WEC ENERGY GROUP, INC., 10-K filed on 2/20/2026
Annual Report
v3.25.4
Cover Page - USD ($)
$ in Billions
12 Months Ended
Dec. 31, 2025
Jan. 31, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Document Transition Report false    
Entity File Number 001-09057    
Entity Registrant Name WEC ENERGY GROUP, INC.    
Entity Tax Identification Number 39-1391525    
Entity Incorporation, State or Country Code WI    
Entity Address, Address Line One 231 West Michigan Street    
Entity Address, Address Line Two P.O. Box 1331    
Entity Address, City or Town Milwaukee    
Entity Address, State or Province WI    
Entity Address, Postal Zip Code 53201    
City Area Code 414    
Local Phone Number 221-2345    
Title of 12(b) Security Common Stock, $.01 Par Value    
Trading Symbol WEC    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction false    
Entity Shell Company false    
Entity Public Float     $ 33.5
Entity Common Stock, Shares Outstanding   325,531,361  
Documents Incorporated by Reference
Portions of WEC Energy Group, Inc.'s Definitive Proxy Statement on Schedule 14A for its Annual Meeting of Shareholders, to be held on May 7, 2026, are incorporated by reference into Part III hereof.
   
Entity Central Index Key 0000783325    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Amendment Flag false    
v3.25.4
Audit Information
12 Months Ended
Dec. 31, 2025
Audit Information [Abstract]  
Auditor Name DELOITTE & TOUCHE LLP
Auditor Location Milwaukee, Wisconsin
Auditor Firm ID 34
v3.25.4
Consolidated Income Statements - USD ($)
shares in Millions, $ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income Statement [Abstract]      
Operating revenues $ 9,800.1 $ 8,599.9 $ 8,893.0
Operating expenses      
Cost of sales 3,265.8 2,656.0 3,191.2
Other operation and maintenance 2,400.8 2,158.0 2,100.5
Impairments related to Illinois segment 130.0 12.1 178.9
Depreciation and amortization 1,478.5 1,354.5 1,264.2
Property and revenue taxes 280.1 266.5 250.2
Total operating expenses 7,555.2 6,447.1 6,985.0
Operating income 2,244.9 2,152.8 1,908.0
Equity in earnings of transmission affiliates 215.8 207.5 177.5
Other income, net 107.9 178.2 177.7
Interest expense 895.1 815.3 727.4
Gain on debt extinguishments 0.0 (23.1) (0.5)
Other expense (571.4) (406.5) (371.7)
Income before income taxes 1,673.5 1,746.3 1,536.3
Income tax expense 118.0 222.0 204.6
Net income 1,555.5 1,524.3 1,331.7
Preferred stock dividends of subsidiary 1.2 1.2 1.2
Net loss attributed to noncontrolling interests 3.2 4.1 1.2
Net income attributed to common shareholders $ 1,557.5 $ 1,527.2 $ 1,331.7
EPS      
Basic (in dollars per share) $ 4.84 $ 4.83 $ 4.22
Diluted (in dollars per share) $ 4.81 $ 4.83 $ 4.22
Weighted average common shares outstanding      
Basic (in shares) 321.9 316.2 315.4
Diluted (in shares) 323.8 316.5 315.9
v3.25.4
Consolidated Statements of Comprehensive Income - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Statement of Other Comprehensive Income [Abstract]      
Net income $ 1,555.5 $ 1,524.3 $ 1,331.7
Derivatives accounted for as cash flow hedges      
Reclassification of realized derivative gains to net income, net of tax (0.2) (0.3) (0.3)
Defined benefit plans      
Pension and OPEB adjustments arising during the period, net of tax 0.2 0.1 (0.6)
Amortization of pension and OPEB costs included in net periodic benefit cost, net of tax 0.2 0.1 0.0
Defined benefit plans, net 0.4 0.2 (0.6)
Other comprehensive income (loss), net of tax 0.2 (0.1) (0.9)
Comprehensive income 1,555.7 1,524.2 1,330.8
Preferred stock dividends of subsidiary 1.2 1.2 1.2
Comprehensive loss attributed to noncontrolling interests 3.2 4.1 1.2
Comprehensive income attributed to common shareholders $ 1,557.7 $ 1,527.1 $ 1,330.8
v3.25.4
Consolidated Balance Sheets - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Current assets    
Cash and cash equivalents $ 27.6 $ 9.8
Accounts receivable and unbilled revenues, net of reserves of $148.7 and $162.8, respectively 2,062.7 1,669.3
Materials, supplies, and inventories 803.4 813.2
Prepaid taxes 178.8 214.9
Other prepayments 92.4 82.6
Other 119.8 121.9
Current assets 3,284.7 2,911.7
Long-term assets    
Property, plant, and equipment, net of accumulated depreciation and amortization of $12,411.5 and $11,611.9, respectively 38,278.1 34,645.4
Regulatory assets (December 31, 2025 and December 31, 2024 include $67.5 and $76.5, respectively, related to WEPCo Environmental Trust) 3,156.3 3,339.7
Equity investment in transmission affiliates 2,280.4 2,108.9
Goodwill 3,052.8 3,052.8
Pension and OPEB assets 1,082.4 968.5
Other 383.6 336.2
Long-term assets 48,233.6 44,451.5
Total assets 51,518.3 47,363.2
Current liabilities    
Short-term debt 1,924.7 1,116.6
Current portion of long-term debt (December 31, 2025 and December 31, 2024 include $9.3 and $9.2, respectively, related to WEPCo Environmental Trust) 1,519.4 1,729.0
Accounts payable 1,140.1 1,137.1
Other 1,009.2 859.2
Current liabilities 5,593.4 4,841.9
Long-term liabilities    
Long-term debt (December 31, 2025 and December 31, 2024 include $67.4 and $76.4, respectively, related to WEPCo Environmental Trust) 18,498.1 17,178.1
Finance lease obligations 372.0 303.3
Deferred income taxes 5,891.7 5,514.7
Deferred revenue, net 314.2 334.6
Regulatory liabilities 4,121.3 3,958.0
Intangible liabilities 580.3 566.8
Environmental remediation liabilities 484.1 445.8
AROs 647.0 580.0
Other 963.4 838.1
Long-term liabilities 31,872.1 29,719.4
Commitments and contingencies (Note 24)
Common shareholders' equity    
Common stock – $0.01 par value; 650,000,000 shares authorized; 325,461,519 and 317,680,855 shares outstanding, respectively 3.3 3.2
Additional paid in capital 5,124.4 4,315.8
Retained earnings 8,493.5 8,083.8
Accumulated other comprehensive loss (7.6) (7.8)
Common shareholders' equity 13,613.6 12,395.0
Preferred stock of subsidiary 30.4 30.4
Noncontrolling interest 408.8 376.5
Total liabilities and equity $ 51,518.3 $ 47,363.2
v3.25.4
Consolidated Balance Sheets (Parenthetical) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Statement of Financial Position [Abstract]    
Accounts receivable and unbilled revenues, reserves $ 148.7 $ 162.8
Property, plant, and equipment, accumulated depreciation and amortization $ 12,411.5 $ 11,611.9
Common stock, par value $ 0.01 $ 0.01
Common stock, shares authorized 650,000,000 650,000,000
Common stock, shares outstanding 325,461,519 317,680,855
Balance sheets    
Regulatory assets (December 31, 2025 and December 31, 2024 include $67.5 and $76.5, respectively, related to WEPCo Environmental Trust) $ 3,156.3 $ 3,339.7
Current portion of long-term debt (December 31, 2025 and December 31, 2024 include $9.3 and $9.2, respectively, related to WEPCo Environmental Trust) 1,519.4 1,729.0
Long-term debt (December 31, 2025 and December 31, 2024 include $67.4 and $76.4, respectively, related to WEPCo Environmental Trust) 18,498.1 17,178.1
WEPCo Environmental Trust    
Balance sheets    
Regulatory assets (December 31, 2025 and December 31, 2024 include $67.5 and $76.5, respectively, related to WEPCo Environmental Trust) 67.5 76.5
Current portion of long-term debt (December 31, 2025 and December 31, 2024 include $9.3 and $9.2, respectively, related to WEPCo Environmental Trust) 9.3 9.2
Long-term debt (December 31, 2025 and December 31, 2024 include $67.4 and $76.4, respectively, related to WEPCo Environmental Trust) $ 67.4 $ 76.4
v3.25.4
Consolidated Statements of Cash Flows - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Operating activities      
Net income $ 1,555.5 $ 1,524.3 $ 1,331.7
Reconciliation to cash provided by operating activities      
Depreciation and amortization 1,478.5 1,354.5 1,264.2
Deferred income taxes and ITCs, net 368.5 529.0 219.4
Impairments related to Illinois segment 130.0 12.1 178.9
Contributions and payments related to pension and OPEB plans (13.7) (14.5) (16.7)
Equity income in transmission affiliates, net of distributions (29.2) (57.4) (33.0)
Change in -      
Accounts receivable and unbilled revenues, net (411.8) (161.5) 340.6
Materials, supplies, and inventories 9.8 (38.0) 41.9
Prepaid taxes 36.1 (41.0) 27.9
Collateral on deposit (25.4) 84.3 22.1
Other current assets 11.4 (34.4) 8.4
Accounts payable 46.4 99.7 (254.0)
Amounts refundable to customers 43.6 (2.2) (9.0)
Other current liabilities 86.5 13.8 56.5
Other, net 93.2 (56.9) (160.5)
Net cash provided by operating activities 3,379.4 3,211.8 3,018.4
Investing activities      
Capital expenditures (4,398.1) (2,781.1) (2,492.9)
Acquisition of Hardin III, net of cash acquired of $0.2 (406.1) 0.0 0.0
Acquisition of Delilah I, net of cash acquired of $0.6 0.0 (462.5) 0.0
Acquisition of Maple Flats, net of cash acquired of $0.5 0.0 (431.2) 0.0
Acquisition of West Riverside 0.0 (97.9) (95.3)
Acquisition of Red Barn 0.0 (2.1) (143.8)
Acquisition of Whitewater 0.0 0.0 (76.0)
Acquisition of Sapphire Sky, net of cash acquired of $0.3 0.0 0.0 (442.6)
Acquisition of Samson I, net of cash acquired of $5.2 0.0 0.0 (257.3)
Capital contributions to transmission affiliates (142.4) (45.5) (63.7)
Reimbursement for ATC's transmission infrastructure upgrades 39.8 8.1 0.1
Other, net 32.1 9.7 13.3
Net cash used in investing activities (4,874.7) (3,802.5) (3,558.2)
Financing activities      
Exercise of stock options 39.1 23.7 6.3
Issuance of common stock, net 761.9 163.4 0.0
Purchase of common stock (1.3) (3.2) (16.6)
Dividends paid on common stock (1,147.8) (1,056.2) (984.2)
Issuance of long-term debt 2,844.5 4,460.9 2,170.0
Retirement of long-term debt (1,728.9) (2,138.0) (1,005.4)
Change in commercial paper 806.9 (902.8) 373.7
Purchase of additional ownership interest in Samson I from noncontrolling interest 0.0 (28.1) 0.0
Payments for debt extinguishment and issuance costs (39.9) (45.9) (14.2)
Other, net (10.5) (6.1) (6.8)
Net cash provided by financing activities 1,524.0 467.7 522.8
Net change in cash, cash equivalents, and restricted cash 28.7 (123.0) (17.0)
Cash, cash equivalents, and restricted cash at beginning of year 42.2 165.2 182.2
Cash, cash equivalents, and restricted cash at end of year $ 70.9 $ 42.2 $ 165.2
v3.25.4
Consolidated Statement of Cash Flows (Parenthetical) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Hardin III      
Acquisitions      
Cash acquired $ 0.2    
Delilah I      
Acquisitions      
Cash acquired   $ 0.6  
Maple Flats      
Acquisitions      
Cash acquired   $ 0.5  
Sapphire Sky      
Acquisitions      
Cash acquired     $ 0.3
Samson I      
Acquisitions      
Cash acquired     $ 5.2
v3.25.4
Consolidated Statements of Equity - USD ($)
$ in Millions
Total
Total common shareholders' equity
Common stock
Additional paid-in capital
Retained earnings
Accumulated other comprehensive loss
Preferred stock of subsidiary
Noncontrolling interests
Balance at Dec. 31, 2022 $ 11,616.6 $ 11,376.9 $ 3.2 $ 4,115.2 $ 7,265.3 $ (6.8) $ 30.4 $ 209.3
Equity                
Net income attributed to common shareholders 1,331.7 1,331.7 0.0 0.0 1,331.7 0.0 0.0 0.0
Net loss attributed to noncontrolling interests 1.2 0.0 0.0 0.0 0.0 0.0 0.0 1.2
Other comprehensive income (loss) (0.9) (0.9) 0.0 0.0 0.0 (0.9) 0.0 0.0
Issuance of common stock, net 0.0              
Common stock dividends (984.2) (984.2) 0.0 0.0 (984.2) 0.0 0.0 0.0
Exercise of stock options 6.3 6.3 0.0 6.3 0.0 0.0 0.0 0.0
Purchase of common stock (16.6) (16.6) 0.0 (16.6) 0.0 0.0 0.0 0.0
Acquisition of noncontrolling interests 114.9 0.0 0.0 0.0 0.0 0.0 0.0 114.9
Distributions to noncontrolling interests (6.0) 0.0 0.0 0.0 0.0 0.0 0.0 (6.0)
Stock-based compensation and other 10.9 11.0 0.0 11.0 0.0 0.0 0.0 (0.1)
Balance at Dec. 31, 2023 12,071.5 11,724.2 3.2 4,115.9 7,612.8 (7.7) 30.4 316.9
Equity                
Net income attributed to common shareholders 1,527.2 1,527.2 0.0 0.0 1,527.2 0.0 0.0 0.0
Net loss attributed to noncontrolling interests 4.1 0.0 0.0 0.0 0.0 0.0 0.0 4.1
Other comprehensive income (loss) (0.1) (0.1) 0.0 0.0 0.0 (0.1) 0.0 0.0
Issuance of common stock, net 163.4 163.4 0.0 163.4 0.0 0.0 0.0 0.0
Common stock dividends (1,056.2) (1,056.2) 0.0 0.0 (1,056.2) 0.0 0.0 0.0
Exercise of stock options 23.7 23.7 0.0 23.7 0.0 0.0 0.0 0.0
Purchase of common stock (3.2) (3.2) 0.0 (3.2) 0.0 0.0 0.0 0.0
Acquisition of noncontrolling interests 99.4 0.0 0.0 0.0 0.0 0.0 0.0 99.4
Purchase of additional ownership interest in Samson I from noncontrolling interest 28.1 (4.3) 0.0 (4.3) 0.0 0.0 0.0 (32.4)
Distributions to noncontrolling interests (3.3) 0.0 0.0 0.0 0.0 0.0 0.0 (3.3)
Stock-based compensation and other 11.7 11.7 0.0 11.7 0.0 0.0 0.0 0.0
Balance at Dec. 31, 2024 12,801.9 12,395.0 3.2 4,315.8 8,083.8 (7.8) 30.4 376.5
Equity                
Net income attributed to common shareholders 1,557.5 1,557.5 0.0 0.0 1,557.5 0.0 0.0 0.0
Net loss attributed to noncontrolling interests 3.2 0.0 0.0 0.0 0.0 0.0 0.0 3.2
Other comprehensive income (loss) 0.2 0.2 0.0 0.0 0.0 0.2 0.0 0.0
Issuance of common stock, net 761.9 761.9 0.1 761.8 0.0 0.0 0.0 0.0
Common stock dividends (1,147.8) (1,147.8) 0.0 0.0 (1,147.8) 0.0 0.0 0.0
Exercise of stock options 39.1 39.1 0.0 39.1 0.0 0.0 0.0 0.0
Purchase of common stock (1.3) (1.3) 0.0 (1.3) 0.0 0.0 0.0 0.0
Acquisition of noncontrolling interests 45.1 0.0 0.0 0.0 0.0 0.0 0.0 45.1
Distributions to noncontrolling interests (9.6) 0.0 0.0 0.0 0.0 0.0 0.0 (9.6)
Stock-based compensation and other 9.0 9.0 0.0 9.0 0.0 0.0 0.0 0.0
Balance at Dec. 31, 2025 $ 14,052.8 $ 13,613.6 $ 3.3 $ 5,124.4 $ 8,493.5 $ (7.6) $ 30.4 $ 408.8
v3.25.4
Consolidated Statements of Equity (Parenthetical) - $ / shares
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Statement of Stockholders' Equity [Abstract]      
Dividends per share (in dollars per share) $ 3.57 $ 3.34 $ 3.12
v3.25.4
Summary of Significant Accounting Policies
12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
(a) Nature of Operations—WEC Energy Group serves approximately 1.7 million electric customers and 3.0 million natural gas customers, owns approximately 60% of ATC, and owns majority interests in multiple renewable generating facilities as part of its non-utility energy infrastructure segment.

As used in these notes, the term "financial statements" refers to the consolidated financial statements. This includes the income statements, statements of comprehensive income, balance sheets, statements of cash flows, and statements of equity, unless otherwise noted. On our financial statements, we consolidate our majority-owned subsidiaries, which we control, and VIEs, of which we are the primary beneficiary. We reflect noncontrolling interests for the portion of entities that we do not own as a component of consolidated equity separate from the equity attributable to our shareholders. The noncontrolling interests that we reported as equity on our balance sheet as of December 31, 2025 related to the minority interests held by third parties in the renewable generating facilities that are included in our non-utility energy infrastructure segment.

Our financial statements include the accounts of WEC Energy Group, a diversified energy holding company, and the accounts of our subsidiaries in the following reportable segments:

Wisconsin segment – Consists of WE, WPS, and WG, which are engaged primarily in the generation of electricity and the distribution of electricity and natural gas in Wisconsin; and UMERC, which generates electricity and distributes electricity and natural gas to customers located in the Upper Peninsula of Michigan.

Illinois segment – Consists of PGL and NSG, which are engaged primarily in the distribution of natural gas in Illinois.

Other states segment – Consists of MERC and MGU, which are engaged primarily in the distribution of natural gas in Minnesota and Michigan, respectively.

Electric transmission segment – Consists of our approximate 60% ownership interest in ATC, a for-profit, electric transmission company regulated by the FERC and certain state regulatory commissions, and our approximate 75% ownership interest in ATC Holdco, which invests in transmission-related projects outside of ATC's traditional footprint.

Non-utility energy infrastructure segment – Consists of We Power, which is principally engaged in the ownership of electric power generating facilities for long-term lease to WE, and Bluewater, which owns underground natural gas storage facilities in Michigan. WECI, which holds our majority interests in multiple renewable generating facilities, is also included in this segment. See Note 2, Acquisitions, for more information on recently acquired WECI renewable generating facilities.

Corporate and other segment – Consists of the WEC Energy Group holding company, the Integrys holding company, the PELLC holding company, Wispark, Wisvest, WECC, and WBS.

Investments in companies not controlled by us, but over which we have significant influence regarding the operating and financial policies of the investee, are accounted for using the equity method. We use the cumulative earnings approach for classifying distributions received in the statements of cash flows. Under the cumulative earnings approach, we compare the distributions received to cumulative equity method earnings since inception. Any distributions received up to the amount of cumulative equity earnings are considered a return on investment and classified in operating activities. Any excess distributions are considered a return of investment and classified in investing activities.

Our financial statements also reflect our proportionate interests in certain jointly owned utility facilities. See Note 8, Jointly-Owned Utility Facilities, for more information.
(b) Basis of Presentation—We prepare our financial statements in conformity with GAAP. We make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from these estimates.
(c) Cash and Cash Equivalents—Cash and cash equivalents include marketable debt securities with an original maturity of three months or less.
(d) Operating Revenues—The following discussion includes our significant accounting policies related to operating revenues. For additional required disclosures on disaggregation of operating revenues, see Note 4, Operating Revenues.

Revenues from Contracts with Customers

Electric Utility Operating Revenues

Electricity sales to residential and commercial and industrial customers are generally accomplished through requirements contracts, which provide for the delivery of as much electricity as the customer needs. These contracts represent discrete deliveries of electricity and consist of one distinct performance obligation satisfied over time, as the electricity is delivered and consumed by the customer simultaneously. For our Wisconsin residential and commercial and industrial customers and the majority of our Michigan residential and commercial and industrial customers, our performance obligation is bundled to consist of both the sale and the delivery of the electric commodity. In our Michigan service territory, a limited number of residential and commercial and industrial customers can purchase the commodity from a third party. In this case, the delivery of the electricity represents our sole performance obligation.

The transaction price of the performance obligations for residential and commercial and industrial customers is valued using the rates, charges, terms, and conditions of service included in the tariffs of our regulated electric utilities, which have been approved by state regulators. These rates often have a fixed component customer charge and a usage-based variable component charge. We recognize revenue for the fixed component customer charge monthly using a time-based output method. We recognize revenue for the usage-based variable component charge using an output method based on the quantity of electricity delivered each month. Our retail electric rates in Wisconsin include base amounts for fuel and purchased power costs, which also impact our revenues. The electric fuel rules set by the PSCW allow us to defer, for subsequent rate recovery or refund, under- or over-collections of actual fuel and purchased power costs beyond a 2% price variance from the costs included in the rates charged to customers. Our electric utilities monitor the deferral of under-collected costs to ensure that it does not cause them to earn a greater ROE than authorized by the PSCW. In contrast, the rates of our Michigan retail electric customers include recovery of fuel and purchased power costs on a one-for-one basis. In addition, the Wisconsin residential tariffs of WE and WPS include a mechanism for cost recovery or refund of uncollectible expense based on the difference between actual uncollectible write-offs and the amounts recovered in rates.

Wholesale customers who resell power can choose to either bundle capacity and electricity services together under one contract with a supplier or purchase capacity and electricity separately from multiple suppliers. Furthermore, wholesale customers can choose to have our utilities provide generation to match the customer's load, similar to requirements contracts, or they can purchase specified quantities of electricity and capacity. Contracts with wholesale customers that include capacity bundled with the delivery of electricity contain two performance obligations, as capacity and electricity are often transacted separately in the marketplace at the wholesale level. When recognizing revenue associated with these contracts, the transaction price is allocated to each performance obligation based on its relative standalone selling price. Revenue is recognized as control of each individual component is transferred to the customer. Electricity is the primary product sold by our electric utilities and represents a single performance obligation satisfied over time through discrete deliveries to a customer. Revenue from electricity sales is generally recognized as units are produced and delivered to the customer within the production month. Capacity represents the reservation of an electric generating facility and conveys the ability to call on a plant to produce electricity when needed by the customer. The nature of our performance obligation as it relates to capacity is to stand ready to deliver power. This represents a single performance obligation transferred over time, which generally represents a monthly obligation. Accordingly, capacity revenue is recognized on a monthly basis.

The transaction price of the performance obligations for wholesale customers is valued using the rates, charges, terms, and conditions of service, which have been approved by the FERC. These wholesale rates include recovery of fuel and purchased power costs from customers on a one-for-one basis. For the majority of our wholesale customers, the price billed for energy and capacity is a formula-based rate. Formula-based rates initially set a customer's current year rates based on the previous year’s expenses. This is a predetermined formula derived from the utility's costs and a reasonable rate of return. Because these rates are eventually trued up to reflect actual current-year costs, they represent a form of variable consideration in certain circumstances. The variable consideration is estimated and recognized over time as wholesale customers receive and consume the capacity and electricity services.
We are an active participant in the MISO Energy Markets, where we bid our generation into the Day Ahead and Real Time markets and procure electricity for our retail and wholesale customers at prices determined by the MISO Energy Markets. Purchase and sale transactions are recorded using settlement information provided by MISO. These purchase and sale transactions are accounted for on a net hourly position. Net purchases in a single hour are recorded as purchased power in cost of sales, and net sales in a single hour are recorded as resale revenues on our income statements. For resale revenues, our performance obligation is created only when electricity is sold into the MISO Energy Markets.

For all of our customers, consistent with the timing of when we recognize revenue, customer billings generally occur on a monthly basis, with payments typically due in full within 30 days.

Natural Gas Utility Operating Revenues

We recognize natural gas utility operating revenues under requirements contracts with residential, commercial and industrial, and transportation customers served under the tariffs of our regulated utilities. Tariffs provide our customers with the standard terms and conditions, including rates, related to the services offered. Requirements contracts provide for the delivery of as much natural gas as the customer needs. These requirements contracts represent discrete deliveries of natural gas and constitute a single performance obligation satisfied over time. Our performance obligation is both created and satisfied with the transfer of control of natural gas upon delivery to the customer. For most of our customers, natural gas is delivered and consumed by the customer simultaneously. A performance obligation can be bundled to consist of both the sale and the delivery of the natural gas commodity. In certain of our service territories, customers can purchase the commodity from a third party. In this case, the performance obligation only includes the delivery of the natural gas to the customer.

The transaction price of the performance obligations for our natural gas customers is valued using the rates, charges, terms, and conditions of service included in the tariffs of our regulated utilities, which have been approved by state regulators. These rates often have a fixed component customer charge and a usage-based variable component charge. We recognize revenue for the fixed component customer charge monthly using a time-based output method. We recognize revenue for the usage-based variable component charge using an output method based on natural gas delivered each month.

The tariffs of our natural gas utilities include various rate mechanisms that allow them to recover or refund changes in prudently incurred costs from rate case-approved amounts. The rates for all of our natural gas utilities include one-for-one recovery mechanisms for natural gas commodity costs. Under normal circumstances, we defer any difference between actual natural gas costs incurred and costs recovered through rates as a current asset or liability. The deferred balance is returned to or recovered from customers at intervals throughout the year.

In addition, the rates of PGL and NSG, and the residential tariffs of WE, WPS, and WG, include riders or other mechanisms for cost recovery or refund of uncollectible expense based on the difference between actual uncollectible write-offs and the amounts recovered in rates. The rates of PGL and NSG include riders for cost recovery of both environmental cleanup costs and energy conservation and management program costs. Finally, through the end of 2023 and effective again starting January 1, 2025, the rates of MGU include a rider to recover costs incurred to replace or modify natural gas facilities.

Consistent with the timing of when we recognize revenue, customer billings generally occur on a monthly basis, with payments typically due in full within 30 days.

Other Natural Gas Operating Revenues

We have other natural gas operating revenues from Bluewater, which is in our non-utility energy infrastructure segment. Bluewater owns underground natural gas storage facilities in southeastern Michigan and provides natural gas storage and hub services to customers. Bluewater has entered into long-term service agreements for natural gas storage services with WE, WPS, and WG, and also provides limited service to unaffiliated customers. We recognize revenues using a time-based output method through a monthly fixed service fee. Typical storage contract rates consist of firm storage reservation charges and firm injection and withdrawal charges. All amounts associated with the service agreements with WE, WPS, and WG have been eliminated at the consolidated level.

Other Non-Utility Operating Revenues

Wind and solar generation revenues from WECI's ownership interests in renewable generation facilities continued to grow in 2025. See Note 2, Acquisitions, for more information on recent acquisitions. Most of these renewable generation facilities have offtake agreements with unaffiliated third parties for all of the energy to be produced by the facility, some of which are bundled with
capacity and RECs. We consider bundled energy, capacity, and RECs within these offtake agreements to be distinct performance obligations as each are often transacted separately in the marketplace.

When recognizing revenue associated with these contracts, the transaction price is allocated to each performance obligation based on its relative standalone selling price. Revenue is recognized as control of each individual component is transferred to the customer. Revenue from the sale of this renewable energy is generally recognized as units are produced and delivered to the customer within the production month. Capacity represents the reservation of the renewable generation facility and conveys the ability to call on the renewable generation facility to produce electricity when needed by the customer. The nature of our performance obligation as it relates to capacity is to stand ready to deliver power. This represents a single performance obligation transferred over time, which generally represents a monthly obligation. Accordingly, capacity revenue is recognized on a monthly basis. The performance obligation for RECs is recognized at a point-in-time; however, the timing of revenue recognition is the same, as the generation of renewable energy and the recognition of REC revenues generally occur concurrently.

Non-utility operating revenues are also derived from servicing appliances for customers at MERC. These contracts customarily have a duration of one year or less and consist of a single performance obligation satisfied over time. We use a time-based output method to recognize revenues monthly for the service fee.

Consistent with the timing of when we recognize revenue, customer billings for the renewable generation and servicing revenues generally occur on a monthly basis, with payments typically due in full within 30 days.

As part of the construction of the We Power electric generating units, we capitalized interest during construction, which is included in property, plant, and equipment. As allowed by the PSCW, we collected these carrying costs from WE's utility customers during construction. The equity portion of these carrying costs was recorded as a contract liability, which is presented as deferred revenue, net on our balance sheets. We continually amortize the deferred carrying costs to revenues over the related lease term that We Power has with WE. During 2025, 2024, and 2023, we recorded $24.6 million, $24.3 million, and $23.5 million, respectively, of revenues related to these deferred carrying costs.

Other Operating Revenues

Bespoke Resources Current Return

We recognize revenues monthly associated with carrying costs, including financing costs, during the construction period of bespoke resources assigned to WE's very large utility customers under payment and cancellation agreements. These amounts are not considered revenues from contracts with customers as electricity is not yet being provided by WE. Consistent with the timing of when we recognize revenue, customer billings for the bespoke resources that are subject to current return (as opposed to AFUDC) occur on a monthly basis, with payments typically due in full within 45 days.

Alternative Revenues

Alternative revenues are created from programs authorized by regulators that allow our utilities to record additional revenues by adjusting rates in the future, usually as a surcharge applied to future billings, in response to past activities or completed events. Alternative revenue programs allow compensation for the effects of weather abnormalities, other external factors, or demand side management initiatives. Alternative revenue programs can also provide incentive awards if the utility achieves certain objectives and in other limited circumstances. We record alternative revenues when the regulator-specified conditions for recognition have been met. We reverse these alternative revenues as the customer is billed, at which time this revenue is presented as revenues from contracts with customers.

Below is a summary of the alternative revenue programs at our utilities:

The rates of PGL, NSG, and MERC include decoupling mechanisms. These mechanisms differ by state and allow the utilities to recover or refund the differences between actual and authorized margins for certain customer classes.
MERC’s rates include a conservation improvement program rider, which includes a financial incentive for meeting energy savings goals.
WE and WPS provide wholesale electric service to customers under market-based rates and FERC formula rates. The customer is charged a base rate each year based upon a formula using prior year actual costs and customer demand. A true-up is calculated based on the difference between the amount billed to customers for the demand component of their rates and what the actual
cost of service was for the year. The true-up can result in an amount that we will recover from or refund to the customer. We consider the true-up portion of the wholesale electric revenues to be alternative revenues.
(e) Credit Losses—The following discussion includes our significant accounting policies related to credit losses. For additional required disclosures on credit losses, see Note 5, Credit Losses.

Our exposure to credit losses is related to our accounts receivable and unbilled revenue balances, which are primarily generated from the sale of electricity and natural gas by our regulated utility operations. Credit losses associated with our utility operations are analyzed at the reportable segment level as we believe contract terms, political and economic risks, and the regulatory environment are similar at this level as our reportable segments are generally based on the geographic location of the underlying utility operations.

We have an accounts receivable and unbilled revenue balance associated with our non-utility energy infrastructure segment, related to the sale of electricity from our majority-owned renewable generating facilities through agreements with several large high credit quality counterparties.

We evaluate the collectability of our accounts receivable and unbilled revenue balances considering a combination of factors. For some of our larger customers and also in circumstances where we become aware of a specific customer's inability to meet its financial obligations to us, we record a specific allowance for credit losses against amounts due in order to reduce the net recognized receivable to the amount we reasonably believe will be collected. For all other customers, we use the accounts receivable aging method to calculate an allowance for credit losses. Using this method, we classify accounts receivable into different aging buckets and calculate a reserve percentage for each aging bucket based upon historical loss rates. The calculated reserve percentages are updated on at least an annual basis, in order to ensure recent macroeconomic, political, and regulatory trends are captured in the calculation, to the extent possible. Risks identified that we do not believe are reflected in the calculated reserve percentages, are assessed on a quarterly basis to determine whether further adjustments are required.

We monitor our ongoing credit exposure through active review of counterparty accounts receivable balances against contract terms and due dates. Our activities include timely account reconciliation, dispute resolution and payment confirmation. To the extent possible, we work with customers with past due balances to negotiate payment plans, but will disconnect customers for non-payment as allowed by our regulators, if necessary, and employ collection agencies and legal counsel to pursue recovery of defaulted receivables. For our larger customers, detailed credit review procedures may be performed in advance of any sales being made. We sometimes require letters of credit, parental guarantees, prepayments or other forms of credit assurance from our larger customers, including VLCs, to mitigate credit risk.
(f) Materials, Supplies, and Inventories—Our inventories as of December 31 consisted of:
(in millions)20252024
Materials and supplies$416.4 $412.5 
Natural gas in storage292.5 300.2 
Fossil fuel94.5 100.5 
Total$803.4 $813.2 

PGL and NSG price natural gas storage injections at the calendar year average of the costs of natural gas supply purchased. Withdrawals from storage are priced on the LIFO cost method. Inventories stated on a LIFO basis represented approximately 17% and 18% of total inventories at December 31, 2025 and 2024, respectively. The estimated replacement cost of natural gas in inventory at December 31, 2025 and 2024, exceeded the LIFO cost by $94.9 million and $77.9 million, respectively. In calculating these replacement amounts, PGL and NSG used a Chicago city-gate natural gas price per Dth of $3.36 at December 31, 2025, and $3.10 at December 31, 2024.

Substantially all other materials and supplies, natural gas in storage, and fossil fuel inventories are recorded using the weighted-average cost method of accounting.
(g) Regulatory Assets and Liabilities—The economic effects of regulation can result in regulated companies recording costs and revenues that are allowed in the ratemaking process in a period different from the period they would have been recognized by a nonregulated company. When this occurs, regulatory assets and liabilities are recorded on the balance sheet. Regulatory assets represent deferred costs probable of recovery from customers that would have otherwise been charged to expense. Regulatory
liabilities represent amounts that are expected to be refunded to customers in future rates or future costs already collected from customers in rates.

The recovery or refund of regulatory assets and liabilities is based on specific periods determined by our regulators or occurs over the normal operating period of the related assets and liabilities. If a previously recorded regulatory asset is no longer probable of recovery, the regulatory asset is reduced to the amount considered probable of recovery, and the reduction is charged to expense in the current period. See Note 6, Regulatory Assets and Liabilities, for more information.
(h) Property, Plant, and Equipment—We record property, plant, and equipment at cost. Cost includes material, labor, overhead, and both debt and equity components of AFUDC. Additions to and significant replacements of property are charged to property, plant, and equipment at cost; minor items are charged to other operation and maintenance expense. The cost of depreciable utility property less salvage value is charged to accumulated depreciation when property is retired.

We record straight-line depreciation expense over the estimated useful life of utility property using depreciation rates approved by the applicable regulators. Annual utility composite depreciation rates are shown below:
Annual Utility Composite Depreciation Rates 202520242023
WE3.07%3.03%3.03%
WPS3.01%2.92%2.93%
WG2.45%2.61%2.61%
PGL3.34%3.36%3.13%
NSG2.49%2.49%2.46%
MERC2.62%2.60%2.60%
MGU2.87%2.87%2.73%
UMERC3.20%3.01%2.97%

We depreciate our We Power assets over the estimated useful life of the various property components. The components have useful lives of between 10 to 45 years for PWGS 1 and PWGS 2 and 10 to 55 years for ER 1 and ER 2.

We depreciate our WECI assets over the estimated useful life of the property, with wind and solar generating facilities being depreciated over 30 and 35 years, respectively.

We capitalize certain costs related to software developed or obtained for internal use and record these costs to amortization expense over the estimated useful life of the related software, which ranges from 3 to 15 years. If software is retired prior to being fully amortized, the difference is recorded as a loss on the income statement.

Third parties reimburse the utilities for all or a portion of expenditures for certain capital projects. Such contributions in aid of construction costs are recorded as a reduction to property, plant, and equipment.

See Note 7, Property, Plant, and Equipment, for more information.
(i) Allowance for Funds Used During Construction—AFUDC is included in utility plant accounts and represents the cost of borrowed funds (AFUDC-Debt) used during plant construction, and a return on shareholders' capital (AFUDC-Equity) used for construction purposes. AFUDC-Debt is recorded as a reduction of interest expense, and AFUDC-Equity is recorded in other income, net.
The majority of AFUDC is recorded at WE, WPS, WG, UMERC, and WBS. Approximately 50% of WE's, WPS's, WG's, UMERC's, and WBS's retail jurisdictional CWIP expenditures are subject to the AFUDC calculation. AFUDC rates are determined by their respective state commissions, each with specific requirements. Average AFUDC rates are shown below:
2025
Average AFUDC Retail RateAverage AFUDC Wholesale Rate
WE8.65%7.51%
WPS7.82%6.62%
WG8.54%N/A
UMERC6.40%N/A
WBS7.82%N/A

Our regulated utilities and WBS recorded the following AFUDC for the years ended December 31:
(in millions)202520242023
AFUDC-Debt
WE$29.8 $14.6 $13.0 
WPS4.7 3.6 2.9 
UMERC3.4 0.4 — 
WG0.5 0.5 3.4 
WBS0.2 0.1 0.1 
Other0.4 0.2 0.1 
Total AFUDC-Debt$39.0 $19.4 $19.5 
AFUDC-Equity
WE$78.9 $46.0 $41.0 
WPS12.2 9.2 7.6 
UMERC6.3 1.0 — 
WG1.2 2.9 9.8 
WBS0.5 0.3 0.4 
Other0.7 0.4 0.3 
Total AFUDC-Equity$99.8 $59.8 $59.1 

See Note 16, Income Taxes, for more information on how AFUDC-Equity is treated for tax purposes and the related impact on total WEC Energy Group income tax expense.
(j) Cloud Computing Hosting Arrangements that are Service Contracts—We have entered into several cloud computing arrangements that are hosted service contracts as part of projects related to the continuous transformation of technology. These projects include, among other things, a centralized repository for data to improve analytics, reporting, work and asset management, targeted enterprise resource planning systems, human resources management, employee scheduling, geospatial information, training, information technology service management, and customer contact systems. We present prepaid hosting fees that are service contracts in either prepayments or other long-term assets on our balance sheets and amortize them as the hosting services are received. Amortization expense, as well as the fees associated with the hosting arrangements, is recorded in other operation and maintenance expense on our income statements.

At December 31, 2025 and 2024, we had $27.0 million and $17.0 million, respectively, of capitalized implementation costs related to cloud computing arrangements that are hosted service contracts. We amortize the implementation costs on a straight-line basis over the cloud computing service arrangement term once the component of the hosted service is ready for its intended use. Accumulated amortization at December 31, 2025 and 2024, was $5.8 million and $4.1 million, respectively. Amortization expense for the years ended December 31, 2025, 2024, and 2023 was not significant. The presentation of the implementation costs, along with the related accumulated amortization, follows the prepaid hosting fees.
(k) Asset Impairment—Goodwill and other intangible assets with indefinite lives are subject to an annual impairment test. Interim impairment tests are performed when impairment indicators are present. During the third quarter of each year, we perform an annual impairment test for all of our reporting units that carried a goodwill balance. The carrying amount of the reporting unit's goodwill is considered not recoverable if the carrying amount of the reporting unit's net assets exceeds the reporting unit's fair
value. An impairment loss is recorded as the excess of the carrying amount of the goodwill over its fair value. For our indefinite-lived intangible assets, an impairment loss is recognized when the carrying amount of an asset is not recoverable and exceeds its fair value. An impairment loss is measured as the excess of the carrying amount of the intangible asset over its fair value. No impairment losses were recorded for our indefinite-lived intangible assets during the years ended December 31, 2025, 2024, and 2023. See Note 10, Goodwill and Intangibles, for more information.

We periodically assess the recoverability of certain long-lived assets when factors indicate the carrying value of such assets may be impaired or such assets are planned to be sold. Long-lived assets that would be subject to an impairment assessment generally include any assets within regulated operations that may not be fully recovered from our customers as a result of regulatory decisions that will be made in the future, as well as assets within nonregulated operations that are proposed to be sold or are currently generating operating losses. An impairment loss is recognized when the carrying amount of an asset is not recoverable and exceeds its fair value. The carrying amount of an asset is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. An impairment loss is measured as the excess of the carrying amount of the asset over its fair value.

We also periodically assess the recoverability of our non-utility long-lived assets, which includes reviewing current activities, changes in the conditions of our renewable generating facilities, and market conditions in which they operate to determine the existence of any indicators requiring an impairment analysis. Indicators of potential impairment for a non-utility long-lived asset group, generally an individual renewable generation project, include adverse changes in the financial condition of a customer to our offtake agreements, a significant decline in the forecasted operating revenues and earnings of our renewable generation projects, and deterioration in the performance of our renewable generation projects.

We assess the likelihood of a disallowance of part of the cost of recently completed plant by considering factors such as applicable regulatory environment changes, our own recent rate orders, as well as recent rate orders of other regulated entities in similar jurisdictions. When it becomes probable that part of the cost of recently completed plant will be disallowed for rate-making purposes, we assess whether a reasonable estimate of the amount of the disallowance can be made. The estimated amount of the probable disallowance will then be deducted from the reported cost of the plant and recognized as an impairment loss.

When it becomes probable that a generating unit will be retired before the end of its useful life, we assess whether the generating unit meets the criteria for abandonment accounting. Generating units that are considered probable of abandonment are expected to cease operations in the near term, significantly before the end of their original estimated useful lives. If a generating unit meets the applicable criteria to be considered probable of abandonment, and the unit has been abandoned, we assess the likelihood of recovery of the remaining net book value of that generating unit at the end of each reporting period. If it becomes probable that regulators will disallow full recovery as well as a return on the remaining net book value of a generating unit that is either abandoned or probable of being abandoned, an impairment loss may be required. An impairment loss would be recorded if the remaining net book value of the generating unit is greater than the present value of the amount expected to be recovered from ratepayers, using an incremental borrowing rate. See Note 6, Regulatory Assets and Liabilities, and Note 7, Property, Plant, and Equipment, for more information.

We periodically assess the recoverability of equity method investments when factors indicate the carrying amount of such assets may be impaired. Equity method investments are assessed for impairment by comparing the fair values of these investments to their carrying amounts if a fair value assessment was completed or by reviewing for the presence of impairment indicators. If an impairment exists, and it is determined to be other-than-temporary, an impairment loss is recognized equal to the amount by which the carrying amount exceeds the investment's fair value.

We recorded the following impairment losses on our income statements in the following segments during the years ended December 31:
(in millions)202520242023
Illinois$130.0 
(1)
$12.1 
(2)
$178.9 
(3)
Non-utility energy infrastructure (4)
15.9 — — 
Total impairment losses$145.9 $12.1 $178.9 

(1)    Represents a probable disallowance of certain capital costs at PGL under the QIP rider. See Note 26, Regulatory Environment, for more information.
(2)    Represents a disallowance of certain previously incurred capital costs at PGL resulting from an ICC order received in August 2024 related to the 2016 annual prudency review of the QIP rider. See Note 26, Regulatory Environment, for more information.

(3)    Represents a disallowance of certain previously incurred capital costs resulting from PGL's and NSG's November 2023 rate orders from the ICC. See Note 26, Regulatory Environment, for more information.

(4)    Represents impairment losses related to storm damage at certain of WECI's renewable generation facilities.
(l) Asset Retirement Obligations—We recognize, at fair value, legal obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development, and normal operation of the assets. An ARO liability is recorded, when incurred, for these obligations as long as the fair value can be reasonably estimated, even if the timing or method of settling the obligation is unknown. The associated retirement costs are capitalized as part of the related long-lived asset and are depreciated over the useful life of the asset. The ARO liabilities are accreted each period using the credit-adjusted risk-free interest rates associated with the expected settlement dates of the AROs. These rates are determined when the obligations are incurred. Subsequent changes resulting from revisions to the timing or the amount of the original estimate of undiscounted cash flows are recognized as an increase or a decrease to the carrying amount of the liability and the associated capitalized retirement costs. For our regulated entities, we recognize regulatory assets or liabilities for the timing differences between when we recover an ARO in rates and when we recognize the associated retirement costs. See Note 9, Asset Retirement Obligations, for more information.
(m) Finite-Lived Intangible Asset and Liabilities—Our finite-lived intangible asset and liabilities include revenue contracts, consisting of PPAs and a proxy revenue swap, in addition to interconnection agreements, which resulted from the acquisitions of renewable generation facilities by WECI in our non-utility energy infrastructure segment. Intangible asset and liabilities are amortized on a straight-line basis over their estimated useful lives, which is the term of the related agreement. Amortization of the revenue intangible asset and liabilities are recorded within operating revenues in the income statements. Amortization of the interconnection agreement intangible liabilities is recorded within other operation and maintenance in the income statements. The straight-line method of amortization is used because it best reflects the pattern in which the economic benefits of the intangibles are consumed or otherwise used. The amounts and useful lives assigned to the intangible asset and liabilities assumed impact the amount and timing of future amortization. See Note 10, Goodwill and Intangibles, for more information.
(n) Stock-Based Compensation—In accordance with the Omnibus Stock Incentive Plan, we provide long-term incentives through our equity interests to our non-employee directors, officers, and other key employees. The plan provides for the granting of stock options, restricted stock, performance shares, and other stock-based awards. Awards may be paid in common stock, cash, or a combination thereof. In addition to those shares of common stock that were subject to awards outstanding as of May 6, 2021, when the plan was last approved by shareholders, 9.0 million shares were reserved for issuance under the plan.

We recognize stock-based compensation expense on a straight-line basis over the requisite service period. Awards classified as equity awards are measured based on their grant-date fair value. Awards classified as liability awards are recorded at fair value each reporting period. We account for forfeitures as they occur.

Stock Options

We grant non-qualified stock options that generally vest on a cliff-basis after three years. The exercise price of a stock option under the plan cannot be less than 100% of our common stock's fair market value on the grant date. Historically, all stock options have been granted with an exercise price equal to the fair market value of our common stock on the date of the grant. Options vest immediately upon retirement, death, or disability; however, they may not be exercised within six months of the grant date except in connection with certain termination of employment events following a change in control. Options expire no later than 10 years from the date of the grant.
Our stock options are classified as equity awards. The fair value of our stock options was calculated using a binomial option-pricing model. The following table shows the estimated weighted-average fair value per stock option granted along with the weighted-average assumptions used in the valuation models:
202520242023
Stock options granted231,024 294,990 257,780 
Estimated weighted-average fair value per stock option$18.23 $16.19 $19.58 
Assumptions used to value the options:
Risk-free interest rate
4.2% – 4.6%
3.9% – 5.4%
3.8% – 4.8%
Dividend yield4.1 %3.8 %3.2 %
Expected volatility22.0 %22.0 %22.0 %
Expected life (years)8.38.48.3

The risk-free interest rate was based on the United States Treasury interest rate with a term consistent with the expected life of the stock options. The dividend yield was based on our dividend rate at the time of the grant and historical stock prices. Expected volatility and expected life assumptions were based on our historical experience.

Restricted Shares

Restricted shares granted to employees generally have a vesting period of three years with one-third of the award vesting on each anniversary of the grant date. Restricted shares granted to non-employee directors fully vest after one year.

Our restricted shares are classified as equity awards.

Performance Units

Officers and other key employees are granted performance units under the WEC Energy Group Performance Unit Plan. All grants of performance units are settled in cash and are accounted for as liability awards accordingly. Performance units accrue forfeitable dividend equivalents in the form of additional performance units. The fair value of the performance units reflects our estimate of the final expected value of the awards, which is based on our stock price and performance achievement under the terms of the award. Stock-based compensation costs are generally recorded over the performance period, which is three years.

Pursuant to the terms of the WEC Energy Group Performance Unit Plan, the Compensation Committee selected multiple performance measures that will be weighted to determine the ultimate payout of the performance unit awards. The ultimate number of units that will be paid out will be based on our total shareholder return compared to the total shareholder return of a peer group of companies over three years (55%), and our performance against the weighted average authorized ROE of all of our utility subsidiaries (45%). In addition, the Compensation Committee selected the level of our stock price to earnings ratio compared to our peer companies as a performance measure that can increase the payout by up to 25%. In no event can the performance unit payout be greater than 200% of the target award.

See Note 11, Common Equity, for more information on our stock-based compensation plans.
(o) Earnings Per Share—We compute basic EPS by dividing our net income attributed to common shareholders by the weighted-average number of common shares outstanding during the period. Diluted EPS is computed in a similar manner, but includes the exercise, settlement, and/or conversion of all potentially dilutive securities. Our potentially dilutive securities include stock options, forward equity sales contracts, and shares issuable upon the conversion of our convertible debt instruments.

The dilutive impacts from our in-the-money stock options and forward equity sales contract are calculated using the treasury stock method. The calculation of diluted EPS for the year ended December 31, 2025 excluded 58,533 shares issuable under our forward equity sales contract as their effect was anti-dilutive. The calculation of diluted EPS for the years ended December 31, 2024 and 2023 excluded 66,870 and 1,716,286 stock options, respectively, that had an anti-dilutive effect. No stock options had an anti-dilutive effect for the year ended December 31, 2025, and we did not have any forward equity sales contracts prior to 2025.
Potentially dilutive common shares issuable upon conversion of our convertible debt instruments are calculated using the if-converted method. For the year ended December 31, 2025, there were no shares of our common stock related to the potential conversion of the 2028 Notes (issued in June 2025) included in our diluted EPS calculation as the impact was anti-dilutive. For the year ended December 31, 2024, there were no shares of our common stock related to the potential conversion of the 2027 Notes and 2029 Notes (both issued in 2024) included in our diluted EPS calculation as the impact was anti-dilutive.

See Note 11, Common Equity, for more information on the computation of our basic and diluted EPS.
(p) Leases—We recognize a right of use asset and lease liability for operating and finance leases with a term of greater than one year. As a policy election, we account for each lease component separately from the nonlease components of a contract.

We are currently party to several easement agreements that allow us access to land we do not own for the purpose of constructing and maintaining certain electric power and natural gas equipment. The majority of payments we make related to easements relate to our renewable generating facilities. We have not classified our easements as leases because we view the entire parcel of land specified in our easement agreements to be the identified asset, not just that portion of the parcel that contains our easement. As such, we have concluded that we do not control the use of an identified asset related to our easement agreements, nor do we obtain substantially all of the economic benefits associated with these shared-use assets.

See Note 15, Leases, for more information.
(q) Income Taxes—In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. The amendments require additional disclosures, primarily related to income taxes paid and the rate reconciliation table. The amendments require disclosures on specific categories in the rate reconciliation table, as well as additional information for reconciling items that meet a quantitative threshold. For income taxes paid, additional disclosures are required to disaggregate federal, state, and foreign income taxes paid, with additional disclosures for income taxes paid that meet a quantitative threshold. We adopted ASU No. 2023-09 on January 1, 2025, on a retroactive basis, with the required disclosures first included in our 2025 Annual Report on Form 10-K.

We follow the liability method in accounting for income taxes. Accounting guidance for income taxes requires the recording of deferred assets and liabilities to recognize the expected future tax consequences of events that have been reflected in our financial statements or tax returns and the adjustment of deferred tax balances to reflect tax rate changes. We are required to assess the likelihood that our deferred tax assets would expire before being realized. If we conclude that certain deferred tax assets are likely to expire before being realized, a valuation allowance would be established against those assets. GAAP requires that, if we conclude in a future period that it is more likely than not that some or all of the deferred tax assets would be realized before expiration, we reverse the related valuation allowance in that period. Any change to the allowance, as a result of a change in judgment about the realization of deferred tax assets, is reported in income tax expense.

ITCs are deferred and amortized over the life of the assets. PTCs are recognized in the period in which such credits are generated. The amount of the credit is based upon power production from our qualifying generation facilities. We file a consolidated federal income tax return. Accordingly, we allocate federal current tax expense, benefits, and credits to our subsidiaries based on their separate tax computations and our ability to monetize all credits on our consolidated federal return.

We recognize interest and penalties accrued, related to unrecognized tax benefits, in income tax expense in our income statements.

The IRA contains a tax credit transferability provision that allows us to sell PTCs and ITCs produced after December 31, 2022, to third parties. Under this transferability provision, we entered into agreements to sell the majority of the PTCs and ITCs we generated in 2023, 2024, and 2025 to third parties. See Note 16, Income Taxes, for more information on the PTCs we sold. We have also entered into an agreement to sell the majority of PTCs that we expect to generate in 2026 to third parties. We elect to account for tax credits transferred under the scope of ASC 740. We include the discount from the sale of tax credits as a component of income tax expense. We also include any expected proceeds from the sale of tax credits in the evaluation of the realizability of deferred tax assets related to PTCs and ITCs. The sale of tax credits is presented in the operating activities section of the statements of cash flows consistent with the presentation of cash taxes paid.

In April 2023, the IRS issued Revenue Procedure 2023-15, which provides a safe harbor method of accounting that taxpayers may use to determine whether expenses to repair, maintain, replace, or improve natural gas transmission and distribution property must be capitalized for tax purposes. We adopted the safe harbor method of accounting for certain of our utilities on our 2023 tax return
and adopted the safe harbor method of accounting for our remaining utilities on our 2024 tax return, which increased our deferred tax liabilities.

See Note 16, Income Taxes, for more information.
(r) Fair Value Measurements—Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price).

Fair value accounting rules provide a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The three levels of the fair value hierarchy are defined as follows:

Level 1 – Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis.

Level 2 – Pricing inputs are observable, either directly or indirectly, but are not quoted prices included within Level 1. Level 2 includes those financial instruments that are valued using external inputs within models or other valuation methods.

Level 3 – Pricing inputs include significant inputs that are generally less observable from objective sources. These inputs may be used with internally developed methods that result in management's best estimate of fair value. Level 3 instruments include those that may be more structured or otherwise tailored to customers' needs.

Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. We use a mid-market pricing convention (the mid-point price between bid and ask prices) as a practical measure for valuing certain derivative assets and liabilities. We primarily use a market approach for recurring fair value measurements and attempt to use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs.

When possible, we base the valuations of our assets and liabilities on quoted prices for identical assets and liabilities in active markets. These valuations are classified in Level 1. The valuations of certain contracts not classified as Level 1 may be based on quoted market prices received from counterparties and/or observable inputs for similar instruments. Transactions valued using these inputs are classified in Level 2. Certain derivatives, such as FTRs and TCRs, are categorized in Level 3 due to the significance of unobservable or internally-developed inputs. FTRs and TCRs are valued using auction prices from the applicable RTO.

See Note 17, Fair Value Measurements, for more information.
(s) Derivative Instruments—We use derivatives as part of our risk management program to manage the risks associated with the price volatility of interest rates, purchased power, generation, and natural gas costs for the benefit of our customers and shareholders. Our approach is non-speculative and designed to mitigate risk. Regulated hedging programs are approved by our state regulators.

We record derivative instruments on our balance sheets as assets or liabilities measured at fair value unless they qualify for the normal purchases and sales exception, and are so designated. We continually assess our contracts designated as normal and will discontinue the treatment of these contracts as normal if the required criteria are no longer met. Changes in the derivative's fair value are recognized currently in earnings unless specific hedge accounting criteria are met or we receive regulatory treatment for the derivative. For most energy-related physical and financial contracts in our regulated operations that qualify as derivatives, our regulators allow the effects of fair value accounting to be offset to regulatory assets and liabilities.

We classify derivative assets and liabilities as current or long-term on our balance sheets based on the maturities of the underlying contracts. Cash flows from derivative activities are presented in the same category as the item being hedged within operating activities on our statements of cash flows.

Derivative accounting rules provide the option to present certain asset and liability derivative positions net on the balance sheets and to net the related cash collateral against these net derivative positions. We elected not to net these items. On our balance sheets, cash collateral provided to others is reflected in other current assets, and cash collateral received is reflected in other current liabilities. See Note 18, Derivative Instruments, for more information.
(t) Guarantees—We follow the guidance of the Guarantees Topic of the FASB ASC, which requires, under certain circumstances, that the guarantor recognize a liability for the fair value of the obligation undertaken in issuing the guarantee at its inception. See Note 19, Guarantees, for more information.
(u) Employee Benefits—The costs of pension and OPEB plans are expensed over the periods during which employees render service. These costs are distributed among our subsidiaries based on current employment status and actuarial calculations, as applicable. Our regulators allow recovery in rates for the utilities' net periodic benefit cost calculated under GAAP. See Note 20, Employee Benefits, for more information.
(v) Customer Deposits and Credit Balances—When utility customers apply for new service, they may be required to provide a deposit for the service. Customer deposits are recorded within other current liabilities on our balance sheets.

Utility customers can elect to be on a budget plan. Under this type of plan, a monthly installment amount is calculated based on estimated annual usage. During the year, the monthly installment amount is reviewed by comparing it to actual usage. If necessary, an adjustment is made to the monthly amount. Annually, the budget plan is reconciled to actual annual usage. Payments in excess of actual customer usage are recorded within other current liabilities on our balance sheets.
(w) Environmental Remediation Costs—We are subject to federal and state environmental laws and regulations that in the future may require us to pay for environmental remediation at sites where we have been, or may be, identified as a potentially responsible party. Loss contingencies may exist for the remediation of hazardous substances at various potential sites, including CCR landfills and manufactured gas plant sites. See Note 9, Asset Retirement Obligations, for more information regarding CCR landfills and Note 24, Commitments and Contingencies, for more information regarding manufactured gas plant sites.

We record environmental remediation liabilities when site assessments indicate remediation is probable, and we can reasonably estimate the loss or a range of losses. The estimate includes both our share of the liability and any additional amounts that will not be paid by other potentially responsible parties or the government. When possible, we estimate costs using site-specific information but also consider historical experience for costs incurred at similar sites. Remediation efforts for a particular site generally extend over a period of several years. During this period, the laws governing the remediation process may change, as well as site conditions, potentially affecting the cost of remediation.

Our utilities have received approval to defer certain environmental remediation costs, as well as estimated future costs, through a regulatory asset. The recovery of deferred costs is subject to the applicable state regulatory commission's approval.

We review our estimated costs of remediation annually for our manufactured gas plant sites and CCR landfills. We adjust the liabilities and related regulatory assets, as appropriate, to reflect the new cost estimates. Any material changes in cost estimates are adjusted throughout the year.
(x) Customer Concentrations of Credit Risk—The geographic concentration of our customers did not contribute significantly to our overall exposure to credit risk. We periodically review customers' credit ratings, financial statements, and historical payment performance and require them to provide collateral or other security as needed. Although we have a comprehensive credit evaluation process and contractual protections, it is possible that one or more counterparties could fail to perform their obligations, and we could recognize financial losses as a result. Credit risk exposure at WE, WPS, WG, PGL, and NSG is mitigated by their recovery mechanisms for uncollectible expense discussed in Note 1(d), Operating Revenues. There were no customers that accounted for more than 10% of our revenues for the year ended December 31, 2025.
As a result, for the majority of our utility companies, we did not have any significant concentrations of credit risk at December 31, 2025. However, WE has contracts with a small number of customers to provide power to large-scale data centers to support AI and other technology capabilities. This concentration of business with a small number of customers in an industry based on emerging technologies presents several risks. WE is incurring significant costs to construct bespoke resources to serve these customers. Although WE requires these customers to enter into payment and cancellation agreements, WE may still experience significant losses or delayed recovery of these costs. Changes in industry practice or advances in these technologies could reduce the demand for electricity to power data centers, which would reduce our forecasted revenues. Significant capital spend to build out required infrastructure or a downturn in business could weaken their financial condition, liquidity and/or creditworthiness, including their ability to satisfy their reimbursement obligations to us.
v3.25.4
Acquisitions
12 Months Ended
Dec. 31, 2025
Asset Acquisition [Abstract]  
Asset Acquisition [Text Block] ACQUISITIONS
In accordance with Topic 805: Clarifying the Definition of a Business (ASU 2017-01), transactions are evaluated and are accounted for as acquisitions of assets or businesses, and transaction costs are capitalized in asset acquisitions. It was determined that all of the below acquisitions met the criteria of asset acquisitions. The purchase price of certain acquisitions below includes intangibles recorded as long-term assets and long-term liabilities related to PPAs. See Note 10, Goodwill and Intangibles, for more information.

Acquisition of a Solar Generation Facility in Ohio

Upon commercial operation in February 2025, WECI completed the acquisition of a 90% ownership interest in Hardin III, a 250 MW solar generating facility located in Hardin County, Ohio for $406.1 million. The project has an offtake agreement for all of the energy to be produced by the facility for a period of 15 years from the date of commercial operation. Hardin III qualifies for PTCs and is included in the non-utility energy infrastructure segment.

The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at the date of the acquisition.
(in millions)
Net property, plant, and equipment$526.5 
Other current assets0.2 
Other current liabilities(0.4)
Other long-term liabilities(75.1)
Noncontrolling interest(45.1)
Total purchase price$406.1 

Acquisitions of Solar Generation Facilities in Texas

Upon commercial operation in December 2024, WECI completed the acquisition of a 90% ownership interest in Delilah I, a 300 MW solar generating facility in Lamar, Franklin, Hopkins, and Red River counties in Texas. Delilah I was acquired for $462.5 million, which included transaction costs and was net of cash acquired. The project has offtake agreements for all of the energy to be produced by the facility for a period of 15 years from the date of commercial operation. Delilah I qualifies for PTCs and is included in the non-utility energy infrastructure segment.

The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at the date of the acquisition.
(in millions)
Other current assets$0.1 
Net property, plant, and equipment579.8 
Other long-term assets12.4 
Other long-term liabilities(78.3)
Noncontrolling interest(51.5)
Total purchase price$462.5 

In February 2023, WECI completed the acquisition of an 80% ownership interest in Samson I, a commercially operational 250 MW solar generating facility in Lamar, Franklin, Hopkins, and Red River counties in Texas. Samson I was acquired for $257.3 million, which included transaction costs and was net of cash acquired. The project has an offtake agreement for all of the energy to be produced by the facility for a period of 15 years from the date of commercial operation in May 2022. Samson I qualifies for PTCs and is included in the non-utility energy infrastructure segment. In January 2024, WECI acquired an additional 10% ownership interest in Samson I for $28.1 million.
The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at the date of the original acquisition.
(in millions)
Accounts receivable$0.5 
Other current assets0.7 
Net property, plant, and equipment497.2 
Other long-term assets12.3 
Accounts payable(0.5)
Other current liabilities(0.8)
Other long-term liabilities(186.4)
Noncontrolling interest(65.7)
Total purchase price$257.3 

Acquisitions of Electric Generation Facilities in Illinois

Upon commercial operation in November 2024, WECI completed the acquisition of a 90% ownership interest in Maple Flats, a 250 MW solar generating facility in Clay County, Illinois. Maple Flats was acquired for $431.2 million, which included transaction costs and was net of cash acquired. The project has an offtake agreement for all of the energy to be produced by the facility for a period of 15 years from the date of commercial operation. Maple Flats qualifies for PTCs and is included in the non-utility energy infrastructure segment.

The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at the date of the acquisition.
(in millions)
Net property, plant, and equipment$469.5 
Other long-term assets44.5 
Other long-term liabilities(34.9)
Noncontrolling interest(47.9)
Total purchase price$431.2 

In February 2023, upon achievement of commercial operation, WECI completed the acquisition of a 90% ownership interest in Sapphire Sky, a 250 MW wind generating facility in McLean County, Illinois, for a total investment of $442.6 million, which includes transaction costs and is net of cash acquired. The project has an offtake agreement for all of the energy to be produced by the facility for a period of 12 years from the date of commercial operation. Sapphire Sky qualifies for PTCs and is included in the non-utility energy infrastructure segment.

The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at the date of the acquisition.
(in millions)
Accounts receivable$0.8 
Net property, plant, and equipment642.6 
Other long-term assets1.4 
Accounts payable(1.0)
Other long-term liabilities(152.0)
Noncontrolling interest(49.2)
Total purchase price$442.6 
Acquisitions of Electric Generation Facilities in Wisconsin

In December 2025, WE and WPS, along with an unaffiliated utility, signed an agreement to acquire Whitetail, a wind-powered electric generation project with a total capacity of 67.2 MW. This project will be located in Grant County, Wisconsin and WE will own 80% and WPS will own 10%. WE's share of the purchase price is expected to be approximately $178 million and WPS's share of the purchase price is expected to be approximately $22 million. The project is expected to close in late 2027 and it is expected to qualify for PTCs.

In May 2024, WE completed the acquisition of an additional 100 MWs of West Riverside's nameplate capacity for $97.9 million. West Riverside is a commercially operational dual fueled combined cycle generation facility in Beloit, Wisconsin. In June 2023, WE completed the first acquisition of 100 MWs for $95.3 million. After the second acquisition, WE owns 200 MWs, or 27.5%, of West Riverside at a total cost of $193.2 million.

In April 2023, WPS, along with an unaffiliated utility, completed the acquisition of Red Barn, a commercially operational utility-scale wind-powered electric generating facility. The project is located in Grant County, Wisconsin and WPS owns 82 MWs of this project. WPS's share of the cost of this project was $145.9 million. Red Barn qualifies for PTCs.

In January 2023, WE and WPS completed the acquisition of Whitewater, a commercially operational 236.5 MW dual fueled (natural gas and low sulfur fuel oil) combined cycle electric generation facility in Whitewater, Wisconsin, for $76.0 million.
v3.25.4
Dispositions
12 Months Ended
Dec. 31, 2025
Discontinued Operations and Disposal Groups [Abstract]  
DISPOSITIONS DISPOSITION
Wisconsin Segment

Sale of Certain Real Estate by Wisconsin Electric Power Company

In June 2023, we sold approximately 192 acres of real estate at WE's former Pleasant Prairie power plant site that was no longer being utilized in its operations, for $23.0 million, which is net of closing costs. As a result of the sale, a pre-tax gain in the amount of $22.2 million was recorded within other operation and maintenance expense on our income statement. The book value of the real estate included in the sale was not material and, therefore, was not presented as held for sale.
v3.25.4
Operating Revenues
12 Months Ended
Dec. 31, 2025
Revenue from Contract with Customer [Abstract]  
OPERATING REVENUES OPERATING REVENUES
For more information about our significant accounting policies related to operating revenues, see Note 1(d), Operating Revenues.

Disaggregation of Operating Revenues

The following tables present our operating revenues disaggregated by revenue source. We do not have any revenues associated with our electric transmission segment, which includes investments accounted for using the equity method. We disaggregate revenues into categories that depict how the nature, amount, timing, and uncertainty of revenues and cash flows are affected by economic factors. For our segments, revenues are further disaggregated by electric and natural gas operations and then by customer class. Each customer class within our electric and natural gas operations has different expectations of service, energy and demand requirements, and can be impacted differently by regulatory activities within their jurisdictions.
(in millions)WisconsinIllinoisOther StatesTotal Utility
Operations
Non-Utility Energy InfrastructureCorporate
and Other
Reconciling
Eliminations
WEC Energy Group Consolidated
Year ended December 31, 2025      
Electric$5,529.6 $ $ $5,529.6 $ $ $ $5,529.6 
Natural gas1,741.6 1,717.6 508.1 3,967.3 47.0  (44.5)3,969.8 
Total regulated revenues7,271.2 1,717.6 508.1 9,496.9 47.0  (44.5)9,499.4 
Other non-utility revenues  21.8 21.8 243.6  (9.2)256.2 
Total revenues from contracts with customers7,271.2 1,717.6 529.9 9,518.7 290.6  (53.7)9,755.6 
Other operating revenues24.3 (34.0)(2.4)(12.1)479.6  (423.0)
(1)
44.5 
Total operating revenues$7,295.5 $1,683.6 $527.5 $9,506.6 $770.2 $ $(476.7)$9,800.1 

(in millions)WisconsinIllinoisOther StatesTotal Utility
Operations
Non-Utility Energy InfrastructureCorporate
and Other
Reconciling
Eliminations
WEC Energy Group Consolidated
Year ended December 31, 2024      
Electric$4,908.4 $— $— $4,908.4 $— $— $— $4,908.4 
Natural gas1,402.4 1,499.6 419.7 3,321.7 48.4 — (46.0)3,324.1 
Total regulated revenues6,310.8 1,499.6 419.7 8,230.1 48.4 — (46.0)8,232.5 
Other non-utility revenues— — 20.4 20.4 223.9 — (9.1)235.2 
Total revenues from contracts with customers6,310.8 1,499.6 440.1 8,250.5 272.3 — (55.1)8,467.7 
Other operating revenues19.7 102.8 9.7 132.2 419.0 — (419.0)
(1)
132.2 
Total operating revenues$6,330.5 $1,602.4 $449.8 $8,382.7 $691.3 $— $(474.1)$8,599.9 

(in millions)WisconsinIllinoisOther StatesTotal Utility
Operations
Non-Utility Energy InfrastructureCorporate
and Other
Reconciling
Eliminations
WEC Energy Group Consolidated
Year Ended December 31, 2023      
Electric$4,994.6 $— $— $4,994.6 $— $— $— $4,994.6 
Natural gas1,606.7 1,480.5 493.7 3,580.9 61.9 — (60.2)3,582.6 
Total regulated revenues6,601.3 1,480.5 493.7 8,575.5 61.9 — (60.2)8,577.2 
Other non-utility revenues— — 19.6 19.6 197.5 0.1 (9.1)208.1 
Total revenues from contracts with customers6,601.3 1,480.5 513.3 8,595.1 259.4 0.1 (69.3)8,785.3 
Other operating revenues24.6 77.3 5.8 107.7 407.1 — (407.1)
(1)
107.7 
Total operating revenues$6,625.9 $1,557.8 $519.1 $8,702.8 $666.5 $0.1 $(476.4)$8,893.0 

(1)    Amounts eliminated represent lease revenues related to certain plants that We Power leases to WE to supply electricity to its customers. Lease payments are billed from We Power to WE and then recovered in WE's rates as authorized by the PSCW and the FERC. WE operates the plants and is authorized by the PSCW and Wisconsin state law to fully recover prudently incurred operating and maintenance costs in electric rates.
Revenues from Contracts with Customers

Electric Utility Operating Revenues

The following table disaggregates electric utility operating revenues into customer class:
Year Ended December 31
(in millions)202520242023
Residential$2,249.6 $1,996.3 $1,992.3 
Small commercial and industrial1,763.6 1,613.0 1,641.1 
Large commercial and industrial1,057.8 942.6 978.4 
Other30.9 30.2 30.5 
Total retail revenues5,101.9 4,582.1 4,642.3 
Wholesale107.6 102.6 120.4 
Resale267.6 176.7 195.4 
Steam28.4 22.4 25.2 
Other utility revenues24.1 24.6 11.3 
Total electric utility operating revenues$5,529.6 $4,908.4 $4,994.6 

Natural Gas Utility Operating Revenues

The following tables disaggregate natural gas utility operating revenues into customer class:
(in millions)WisconsinIllinoisOther StatesTotal Natural Gas Utility Operating Revenues
Year ended December 31, 2025  
Residential$1,100.2 $1,174.9 $316.5 $2,591.6 
Commercial and industrial563.9 320.0 164.4 1,048.3 
Total retail revenues1,664.1 1,494.9 480.9 3,639.9 
Transportation105.1 291.8 38.8 435.7 
Other utility revenues (1) (2)
(27.6)(69.1)(11.6)(108.3)
Total natural gas utility operating revenues$1,741.6 $1,717.6 $508.1 $3,967.3 

(in millions)WisconsinIllinoisOther StatesTotal Natural Gas Utility Operating Revenues
Year ended December 31, 2024   
Residential$893.1 $945.5 $250.5 $2,089.1 
Commercial and industrial416.8 274.5 123.9 815.2 
Total retail revenues1,309.9 1,220.0 374.4 2,904.3 
Transportation96.8 272.2 33.6 402.6 
Other utility revenues (1)
(4.3)7.4 11.7 14.8 
Total natural gas utility operating revenues$1,402.4 $1,499.6 $419.7 $3,321.7 
(in millions)WisconsinIllinoisOther StatesTotal Natural Gas Utility Operating Revenues
Year Ended December 31, 2023   
Residential$1,012.0 $966.0 $324.4 $2,302.4 
Commercial and industrial506.7 267.1 175.3 949.1 
Total retail revenues1,518.7 1,233.1 499.7 3,251.5 
Transportation93.0 231.9 32.5 357.4 
Other utility revenues (1)
(5.0)15.5 (38.5)(28.0)
Total natural gas utility operating revenues$1,606.7 $1,480.5 $493.7 $3,580.9 

(1)    Includes the revenues subject to the purchased gas recovery mechanisms of our utilities, which fluctuate by segment based on actual natural gas costs incurred at our utilities, compared with the recovery of natural gas costs that were anticipated in rates.

(2)    For our Illinois segment, includes a $75.0 million reduction in revenues recorded in the fourth quarter of 2025 for future billing credits to customers, based on the terms of a proposed settlement in February 2026 to resolve open QIP and UEA proceedings.

Other Non-Utility Operating Revenues

Other non-utility operating revenues consist primarily of the following:
Year Ended December 31
(in millions)202520242023
Renewable generation revenues$209.8 $190.5 $164.9 
We Power revenues24.6 24.3 23.5 
Appliance service revenues21.8 20.4 19.6 
Other — 0.1 
Total other non-utility operating revenues$256.2 $235.2 $208.1 

Other Operating Revenues

Other operating revenues consist primarily of the following:
Year Ended December 31
(in millions)202520242023
Late payment charges$48.1 $48.5 $56.5 
Bespoke resources current return (1)
4.1 — — 
Alternative revenues (2)
(67.7)79.8 47.0 
Other60.0 3.9 4.2 
Total other operating revenues$44.5 $132.2 $107.7 

(1)    Bespoke resources current return consists of carrying costs earned during the construction of bespoke resources assigned to WE's VLCs. See Note 1(d), Operating Revenues, for more information.

(2)    Alternative revenues consist of amounts to be recovered or refunded to customers subject to decoupling mechanisms, wholesale true-ups, and conservation improvement rider true-ups. Negative amounts can result from alternative revenues being reversed to revenues from contracts with customers as the customer is billed for these alternative revenues. For more information about our alternative revenues, see Note 1(d), Operating Revenues.
v3.25.4
Credit Losses
12 Months Ended
Dec. 31, 2025
Credit Loss [Abstract]  
CREDIT LOSSES CREDIT LOSSES
We have included tables below that show our gross third-party receivable balances and the related allowance for credit losses at December 31, 2025 and 2024, by reportable segment.
(in millions)WisconsinIllinoisOther StatesTotal Utility
Operations
Non-Utility Energy InfrastructureCorporate
and Other
WEC Energy Group Consolidated
December 31, 2025
Accounts receivable and unbilled revenues$1,368.8 $654.8 $130.2 $2,153.8 $50.3 $7.3 $2,211.4 
Allowance for credit losses61.7 82.3 4.7 148.7   148.7 
Accounts receivable and unbilled revenues, net (1)
$1,307.1 $572.5 $125.5 $2,005.1 $50.3 $7.3 $2,062.7 
Total accounts receivable, net – past due greater than 90 days (1)
$46.4 $36.8 $6.6 $89.8 $ $ $89.8 
Past due greater than 90 days – collection risk mitigated by regulatory mechanisms (1)
94.6 %100.0 % %89.9 % % %89.9 %

(in millions)WisconsinIllinoisOther StatesTotal Utility
Operations
Non-Utility Energy InfrastructureCorporate
and Other
WEC Energy Group Consolidated
December 31, 2024
Accounts receivable and unbilled revenues$1,149.9 $535.6 $100.6 $1,786.1 $40.0 $6.0 $1,832.1 
Allowance for credit losses73.6 83.9 5.3 162.8 — — 162.8 
Accounts receivable and unbilled revenues, net (1)
$1,076.3 $451.7 $95.3 $1,623.3 $40.0 $6.0 $1,669.3 
Total accounts receivable, net – past due greater than 90 days (1)
$51.8 $30.1 $2.5 $84.4 $— $— $84.4 
Past due greater than 90 days – collection risk mitigated by regulatory mechanisms (1)
93.8 %100.0 %— %93.2 %— %— %93.2 %

(1)    Our exposure to credit losses for certain regulated utility customers is mitigated by regulatory mechanisms we have in place. Specifically, rates related to all of the customers in our Illinois segment, as well as the residential rates of WE, WPS, and WG in our Wisconsin segment, include riders or other mechanisms for cost recovery or refund of uncollectible expense based on the difference between the actual provision for credit losses and the amounts recovered in rates. As a result, at December 31, 2025, $1,290.2 million, or 62.5%, of our net accounts receivable and unbilled revenues balance had regulatory protections in place to mitigate the exposure to credit losses. See Note 26, Regulatory Environment, for more information on PGL and NSG's UEA rider for cost recovery or refund of uncollectible expense based on the difference between actual uncollectible write-offs and amounts recovered in rates.

A rollforward of the allowance for credit losses by reportable segment for the years ended December 31, 2025, 2024, and 2023, is included below:
(in millions)
WisconsinIllinoisOther StatesWEC Energy Group Consolidated
Balance at January 1, 2025$73.6 $83.9 $5.3 $162.8 
Provision for credit losses85.0 55.8 2.0 142.8 
Provision for credit losses deferred for future recovery or refund4.9 (28.7) (23.8)
Write-offs charged against the allowance(151.4)(81.2)(8.4)(241.0)
Recoveries of amounts previously written off49.6 52.5 5.8 107.9 
Balance at December 31, 2025$61.7 $82.3 $4.7 $148.7 

On a consolidated basis, there was a $14.1 million decrease in the allowance for credit losses during the year ended December 31, 2025. This decrease is largely driven by customer write-offs in Wisconsin in addition to a decrease in past due account balances in Wisconsin that we believe was related to a continued focus on collection efforts and lower energy bills in the spring and summer months, enabling customers to pay down their arrears.
(in millions)
WisconsinIllinoisOther StatesWEC Energy Group Consolidated
Balance at January 1, 2024$77.4 $109.7 $6.4 $193.5 
Provision for credit losses52.1 52.3 0.5 104.9 
Provision for credit losses deferred for future recovery or refund43.8 (8.0)— 35.8 
Write-offs charged against the allowance(141.8)(95.0)(6.6)(243.4)
Recoveries of amounts previously written off42.1 24.9 5.0 72.0 
Balance at December 31, 2024$73.6 $83.9 $5.3 $162.8 

On a consolidated basis, there was a $30.7 million decrease in the allowance for credit losses during the year ended December 31, 2024, largely driven by customer write-offs. We also believe that the lower energy costs that customers were seeing, which were driven by warmer than normal weather conditions during most of 2024 and low average natural gas prices, contributed to a reduction in past due accounts receivable balances and a related decrease in the allowance for credit losses.
(in millions)
WisconsinIllinoisOther StatesWEC Energy Group Consolidated
Balance at January 1, 2023$82.0 $111.0 $6.3 $199.3 
Provision for credit losses40.9 26.3 4.8 72.0 
Provision for credit losses deferred for future recovery or refund52.5 35.8 — 88.3 
Write-offs charged against the allowance(131.6)(85.4)(6.6)(223.6)
Recoveries of amounts previously written off33.6 22.0 1.9 57.5 
Balance at December 31, 2023$77.4 $109.7 $6.4 $193.5 
On a consolidated basis, there was a $5.8 million decrease in the allowance for credit losses during the year ended December 31, 2023, primarily related to lower customer energy costs (driven by the warmer weather during the fourth quarter of 2023 when compared to the same quarter in 2022 and lower natural gas prices), which contributed to a reduction in past due accounts receivable balances and a related decrease in the allowance for credit losses. Customer write-offs also contributed to the decrease in the allowance for credit losses.
v3.25.4
Regulatory Assets and Liabilities
12 Months Ended
Dec. 31, 2025
Regulatory Assets and Liabilities Disclosure [Abstract]  
REGULATORY ASSETS AND LIABILITIES REGULATORY ASSETS AND LIABILITIES
The following regulatory assets were reflected on our balance sheets as of December 31:
(in millions)20252024See Note
Regulatory assets (1) (2)
Plant retirement related items (3)
$768.6 $810.5 
Environmental remediation costs (4)
566.0 570.1 24
Pension and OPEB costs (5)
564.5 684.9 20, 26
Income tax related items493.4 438.5 16
AROs185.1 166.7 1(l), 9
Uncollectible expense123.9 151.5 5
SSR (6)
92.6 102.9 
Securitization67.5 76.5 23
Derivatives57.7 38.2 1(s)
Decoupling43.8 110.0 1(d)
Bluewater (7)
37.7 57.7 
Finance and operating leases36.0 22.0 15
Electric transmission costs (8)
30.7 0.4 
Energy efficiency programs (9)
11.6 26.5 
Other, net94.5 122.3 
Total regulatory assets$3,173.6 $3,378.7 
Balance sheet presentation
Other current assets$17.3 $39.0 
Regulatory assets3,156.3 3,339.7 
Total regulatory assets$3,173.6 $3,378.7 

(1)    Based on prior and current rate treatment, we believe it is probable that our utilities will continue to recover from customers the regulatory assets in this table. In accordance with GAAP, our regulatory assets do not include the allowance for ROE that is capitalized for regulatory purposes. This allowance was $20.9 million and $26.7 million at December 31, 2025 and 2024, respectively.

(2)    As of December 31, 2025, we had $183.1 million of regulatory assets not earning a return, $1.3 million of regulatory assets earning a return based on short-term interest rates, $106.1 million of regulatory assets earning a return based on long-term interest rates, and $5.5 million of regulatory assets earning a return based on the applicable utility's ROE. The regulatory assets not earning a return primarily relate to certain environmental remediation costs, decoupling mechanisms, electric transmission costs, unamortized loss on reacquired debt, and uncollectible expense. The other regulatory assets in the table either earn a return at the applicable utility's weighted average cost of capital or the cash has not yet been expended, in which case the regulatory assets are offset by liabilities.

(3)    Primarily represents the net book value of power plants we have both abandoned and retired. For all of these plants, we have approval to collect a return of their remaining net book value. We also have approval to collect a return on all but $100 million of their remaining net book value. For information on the securitization of this $100 million, see Note 23, Variable Interest Entities. These regulatory assets are amortized on a straight-line basis, using the composite depreciation rates approved before the plants were retired, and the amortization is included in depreciation and amortization in the income statement.

(4)    As of December 31, 2025, we had made cash expenditures of $81.9 million related to these environmental remediation costs. The remaining $484.1 million represents our estimated future cash expenditures.

(5)    Primarily represents the unrecognized future pension and OPEB costs related to our defined benefit pension and OPEB plans. We are authorized recovery of these regulatory assets over the average remaining service life of each plan.

(6)    This regulatory asset relates to WE's 2014 announcement to retire the PIPP. Despite WE's intent to retire the PIPP, MISO designated the PIPP as a SSR, which meant the PIPP's operation was necessary for reliability, and the plant could not be shut down until new generation or transmission facilities were built. In December 2014, the PSCW authorized escrow accounting for WE's SSR revenues because of the fluctuations in the actual revenues WE received under the PIPP SSR agreements. The rate order WE received from the PSCW in December 2019 authorized recovery of this SSR regulatory asset over a 15-year period that began on January 1, 2020.

(7)    Primarily relates to costs associated with the long-term service agreements our Wisconsin utilities have with Bluewater for natural gas storage services. The PSCW has approved escrow accounting for these costs. As a result, our Wisconsin utilities defer as a regulatory asset or liability the difference between actual storage costs and those included in rates until recovery or refund is authorized in a future rate proceeding.
(8)    In accordance with the PSCW's approval of escrow accounting for ATC and MISO network transmission expenses for our Wisconsin electric utilities, WE and WPS defer as a regulatory asset or liability the difference between actual transmission costs and those included in rates until recovery or refund is authorized in a future rate proceeding.

(9)    Represents amounts recoverable from customers related to programs at the utilities designed to meet energy efficiency standards.

The following regulatory liabilities were reflected on our balance sheets as of December 31:
(in millions)20252024See Note
Regulatory liabilities
Income tax related items$1,802.4 $1,825.4 16
Removal costs (1)
1,584.7 1,458.2 
Pension and OPEB benefits (2)
301.5 308.5 20, 26
Proposed settlement related to QIP and UEA riders125.0 — 26
Energy costs refundable through rate adjustments119.2 160.8 1(d)
Uncollectible expense73.1 47.2 5
Earnings sharing mechanisms35.8 7.1 26
Derivatives27.4 36.9 1(s)
MERC property tax tracker (3)
23.1 19.3 
Revenue requirements of renewable generation facilities (4)
14.5 44.2 
Other, net103.5 95.7 
Total regulatory liabilities$4,210.2 $4,003.3 
Balance sheet presentation
Other current liabilities$88.9 $45.3 
Regulatory liabilities4,121.3 3,958.0 
Total regulatory liabilities$4,210.2 $4,003.3 

(1)    Represents amounts collected from customers to cover the future cost of property, plant, and equipment removals that are not legally required. Legal obligations related to the removal of property, plant, and equipment are recorded as AROs. See Note 9, Asset Retirement Obligations, for more information on our legal obligations.

(2)    Primarily represents the unrecognized future pension and OPEB benefits related to our defined benefit pension and OPEB plans. We will amortize these regulatory liabilities into net periodic benefit cost over the average remaining service life of each plan.

(3)    MERC defers as a regulatory asset or liability the difference between actual property tax expense and the amount included in rates until
recovery or refund is authorized in a future rate proceeding.

(4)    These amounts represent the deferral of the incremental revenue requirement impact from the delayed in-service date of certain renewable generation facilities constructed by our electric utilities.

Oak Creek Power Plant Units 5-6
In May 2024, OCPP Units 5 and 6 were retired. Due to the retirement of these units and the determination that recovery was probable, their net book value of $68.3 million at December 31, 2025 was classified as a regulatory asset. In addition, a $45.0 million cost of removal reserve related to the units continued to be classified as a regulatory liability at December 31, 2025. Not included in these amounts was $6.3 million of deferred tax liabilities previously recorded for the retired units. Effective with its rate order issued by the PSCW in December 2022, WE received approval to collect a return of and on the entire net book value of OCPP Units 5 and 6 and, as a result, will continue to amortize the regulatory asset on a straight-line basis, using the composite depreciation rates approved by the PSCW before the units were retired. The amortization is included in depreciation and amortization on the income statement. WE also has FERC approval to continue to collect the net book value of OCPP Units 5 and 6 using the approved composite depreciation rates, in addition to a return on the remaining net book value.
v3.25.4
Property, Plant, and Equipment
12 Months Ended
Dec. 31, 2025
Property, Plant and Equipment [Abstract]  
PROPERTY, PLANT AND EQUIPMENT PROPERTY, PLANT, AND EQUIPMENT
Property, plant, and equipment consisted of the following at December 31:
(in millions)20252024
Electric – generation$7,998.3 $6,685.0 
Electric – distribution10,048.9 9,298.9 
Natural gas – distribution, storage, and transmission16,175.0 15,673.0 
Property, plant, and equipment to be retired, net621.7 906.3 
Other2,431.2 2,410.8 
Less: Accumulated depreciation10,180.2 9,401.0 
Net27,094.9 25,573.0 
CWIP3,364.4 1,653.6 
Net utility and non-utility property, plant, and equipment30,459.3 27,226.6 
We Power generation3,250.7 3,284.3 
Renewable generation5,252.4 4,720.8 
Natural gas storage299.6 298.6 
Net non-utility energy infrastructure8,802.7 8,303.7 
Corporate services167.6 172.3 
Other11.3 14.1 
Less: Accumulated depreciation1,559.1 1,393.9 
Net7,422.5 7,096.2 
CWIP60.8 41.3 
Net other property, plant, and equipment7,483.3 7,137.5 
Property under finance leases351.8 291.3 
Less: Accumulated amortization16.3 10.0 
Net leased facilities335.5 281.3 
Total property, plant, and equipment$38,278.1 $34,645.4 

Severance Liability for Plant Retirements

We have severance liabilities related to past and future plant retirements recorded in other current and other long-term liabilities on our balance sheets. Activity related to these severance liabilities for the years ended December 31 was as follows:
(in millions)202520242023
Severance liability at January 1$13.4 $17.8 $16.2 
Severance expense (3.9)
(1)
1.6 
Severance payments(0.7)(0.5)— 
Total severance liability at December 31$12.7 $13.4 $17.8 

(1)    The severance accrual was lowered in 2024 due to workforce realignment efforts.

Wisconsin Segment Plant to be Retired

Oak Creek Power Plant Units 7 and 8

As a result of a PSCW approval in December 2022 for the acquisition and construction of Darien, the retirement of OCPP Units 7 and 8 became probable. Subsequently, we have received PSCW approval for several other renewable and other projects and have also acquired additional projects. On June 25, 2025, we announced plans to extend the lives of OCPP Units 7 and 8, and expect to have the units available to meet high energy demand periods through the end of 2026. These units were originally scheduled to be retired at the end of 2025. The total net book value of WE's ownership share of OCPP Units 7 and 8 was $621.7 million at December 31, 2025, which does not include deferred taxes. This amount was classified as plant to be retired within property, plant, and equipment
on our balance sheet. These units are included in rate base, and WE continues to depreciate them on a straight-line basis using the composite depreciation rates approved by the PSCW.

Columbia Energy Center Units 1 and 2

As a result of a MISO ruling received in June 2021, retirement of the jointly-owned Columbia Units 1 and 2 became probable. Through June 30, 2025, Columbia Units 1 and 2 were expected to be retired by the end of 2029 and, therefore, met the criteria to be considered probable of abandonment.

In conjunction with our new capital plan, we and the other co-owners currently plan to continue coal operations at Columbia Units 1 and 2 through at least 2029, and continue to evaluate the conversion of both units to natural gas. As a result, we and the other co-owners concluded that Columbia Units 1 and 2 (net book value of WPS's ownership share of Columbia Units 1 and 2 was $236.8 million at December 31, 2025, which does not include deferred taxes) no longer meet the criteria necessary to be considered probable of abandonment.

At December 31, 2025, these units continue to be included in rate base, and WPS continues to depreciate them on a straight-line basis using the composite depreciation rates approved by the PSCW.

Samson Solar Energy LLC and Delilah Solar Energy LLC Storm Damage

During several storms that occurred in 2023 and 2024, certain sections of our Samson I solar facility incurred damage. We had previously recognized an impairment loss of $2.8 million related to damage from these storms, and recorded an offsetting $2.8 million receivable for future insurance recoveries. However, in the second quarter of 2025, we determined it was no longer probable that we would receive insurance proceeds sufficient to recover our losses associated with the 2023 and 2024 storms. As a result, the insurance receivable balance was written off, resulting in the recognition of the $2.8 million impairment loss within other operation and maintenance expense on our income statement.

In addition, in March 2025, both our Samson I and Delilah I solar facilities experienced damage from a storm. In the second quarter of 2025, we recognized an impairment loss within other operation and maintenance expense on our income statement in the amount of $8.8 million, related to damage incurred associated with the March 2025 storm. The impairment loss associated with the March 2025 storm was increased from $8.8 million to $12.0 million in the third quarter of 2025 as a result of ongoing damage assessment.

The Peoples Gas Light and Coke Company and North Shore Gas Company Impairments

In the fourth quarter of 2025, PGL recorded a $130.0 million impairment to property, plant, and equipment related to the terms of a proposed settlement that would resolve its open QIP proceedings.

In August 2024, the ICC issued a final order on PGL's 2016 QIP annual reconciliation, which included a disallowance of certain capital costs. As a result, we recorded a $12.1 million impairment to property, plant, and equipment in 2024.

In November 2023, the ICC issued written rate orders that disallowed $177.2 million of previously incurred capital costs related to the construction and improvement of PGL’s service centers and $1.7 million of capital costs related to NSG's construction of a gas infrastructure project. As a result of these disallowances, we recorded a $178.9 million non-cash impairment to property, plant, and equipment in 2023.

See Note 26, Regulatory Environment, for more information.
v3.25.4
Jointly Owned Utility Facilities
12 Months Ended
Dec. 31, 2025
Jointly Owned Utility Plant, Net Ownership Amount [Abstract]  
JOINTLY-OWNED UTILITY FACILITIES JOINTLY-OWNED UTILITY FACILITIES
Our electric utilities hold joint ownership interests in certain electric generating facilities. We are entitled to our share of generating capability and output of each facility equal to our respective ownership interest. We have supplied our own financing for all jointly owned projects. We pay our ownership share of additional construction costs, fuel inventory purchases, and operating expenses, unless specific agreements have been executed to limit our maximum exposure to additional costs. We record our proportionate share of significant jointly owned electric generating facilities as property, plant, and equipment on the balance sheets. In addition, our proportionate share of direct expenses for the joint operation of these plants is recorded within operating expenses in the income statements.

Information related to jointly owned utility facilities in-service at December 31, 2025 was as follows:
CompanyJointly-Owned Utility FacilitiesOwnership
Share of Capacity (MW)
In-Service /Acquisition Date
Operating OwnerProperty, Plant, and EquipmentAccumulated DepreciationCWIP
(in millions, except for percentages and MW)
We Power (1)
ER 1 & ER 2 (2)
83.34 %1,083.4 2010 & 2011WE$2,489.4 $(542.0)$4.6 
WPS
Weston Unit 4 (2)
70.0 %379.8 2008WPS600.6 (242.7)4.5 
WPS
Columbia Units 1 & 2 (2)
27.5 %306.2 1975 & 1978WPL439.1 (201.6)5.0 
WPS
Forward Wind (3)
44.6 %61.5 2008WPS120.3 (63.3)13.9 
WPS
Two Creeks (4)
66.7 %100.0 2020WPS135.7 (22.9) 
WPS
Badger Hollow I (4)
66.7 %100.0 2021WPS146.0 (19.0) 
WPS
Red Barn (3)
90.0 %82.4 2023WPS150.7 (12.8) 
WE
West Riverside (2) (5)
27.5 %190.2 2023 & 2024WPL223.6 (36.7)2.2 
WE
Badger Hollow II (4)
66.7 %100.0 2023WE179.3 (11.8) 
WE, WPS
Paris Solar (4)
90.0 %180.0 2024WE359.3 (11.0) 
WE, WPS
Paris Battery
90.0 %99.0 
2025
WE
236.8 (5.5) 
WE, WPS
Darien Solar (4)
90.0 %225.0 
2025
WE
460.1 (10.7) 

(1)    We Power leases its ownership interest in ER 1 and ER 2 to WE.

(2)    Capacity is based on rated capacity, which is the net power output under average operating conditions with equipment in an average state of repair as of a given month in a given year. Values are primarily based on the net dependable expected capacity ratings for summer 2026 established by tests and may change slightly from year to year. The summer period is the most relevant for capacity planning purposes. This is a result of continually reaching demand peaks in the summer months, primarily due to air conditioning demand.

(3)     Capacity for wind generating facilities is based on nameplate capacity, which is the amount of energy a turbine should produce at optimal wind speeds.

(4)     Capacity for solar generating facilities is based on nameplate capacity, which is the maximum output that a generator should produce at continuous full power.

(5)    WE acquired a 13.8% ownership interest in June 2023 and acquired an additional 13.7% ownership interest in May 2024. See Note 2, Acquisitions, for more information.
Information related to jointly owned utility facilities approved by the PSCW at December 31, 2025 was as follows:
CompanyJointly-Owned Utility FacilitiesOwnership
Share of Capacity (MW)
Date of Expected In-Service
CWIP
(in millions, except for percentages and MW)
WE, WPS
Koshkonong Solar
90.0 %270.0 
2026
$460.6 
WE, WPS
Koshkonong Battery
90.0 %149.0 
2027
150.7 
WE, WPS
Darien Battery
90.0 %68.0 
2027
68.3 
WE, WPS
High Noon Solar
90.0 %270.0 
2027
404.2 
WE, WPS
High Noon Battery
90.0 %149.0 
2027
150.8 
WE, WPS
Ursa Solar Electric Generation Facility
90.0 %180.0 
2027
57.1 
WE, WPS
Saratoga Solar
90.0 %135.0 
2028
39.2 
WE, WPS
Saratoga Battery
90.0 %45.0 
2028
53.2 
WE, WPS
Badger Hollow Wind Energy Generation Facility
90.0 %100.0 
2027
50.0 
WE, WPS
Whitetail
90.0 %60.0 
2027
9.0 
v3.25.4
Asset Retirement Obligations
12 Months Ended
Dec. 31, 2025
Asset Retirement Obligation Disclosure [Abstract]  
ASSET RETIREMENT OBLIGATIONS ASSET RETIREMENT OBLIGATIONS
Our utilities have recorded AROs primarily for the removal of natural gas distribution mains and service pipes (including asbestos and PCBs); asbestos abatement at certain generation and substation facilities, office buildings, and service centers; the removal and dismantlement of a biomass generation facility; the dismantling of wind and solar generation projects; the removal and dismantlement of a battery storage facility; the disposal of PCB-contaminated transformers; the closure of CCR landfills at certain generation facilities; and the removal of above ground and underground storage tanks. Regulatory assets and liabilities are established by our utilities to record the differences between ongoing expense recognition under the ARO accounting rules and the ratemaking practices for retirement costs authorized by the applicable regulators.

WECI has also recorded AROs for the dismantling of our non-utility renewable generation projects.

The following table shows changes to our AROs during the years ended December 31:
(in millions)202520242023
Balance as of January 1$580.0 $374.2 $479.3 
Accretion26.6 18.8 17.2 
Additions29.6 192.7 
(1)
24.0 
Revisions to estimated cash flows23.7 6.4 (133.5)
(2)
Liabilities settled(12.9)(12.1)(12.8)
Balance as of December 31$647.0 $580.0 $374.2 

(1)    AROs increased primarily as a result of AROs being recorded related to the new EPA CCR Rule that was enacted in April 2024. See Note 24, Commitments and Contingencies, for more information.

(2)    AROs decreased primarily due to revisions made to estimated cash flows for changes in removal cost estimates and settlements dates for mains and services at PGL and NSG.
v3.25.4
Goodwill and Intangibles
12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
GOODWILL AND INTANGIBLES GOODWILL AND INTANGIBLES
Goodwill

Goodwill represents the excess of the cost of an acquisition over the fair value of the identifiable net assets acquired. The table below shows our goodwill balances by segment at December 31, 2025. We had no changes to the carrying amount of goodwill during the years ended December 31, 2025 and 2024.
(in millions) Wisconsin IllinoisOther StatesNon-Utility Energy InfrastructureTotal
Goodwill (1)
$2,104.3 $758.7 $183.2 $6.6 $3,052.8 

(1)    We had no accumulated impairment losses related to our goodwill as of December 31, 2025.

During the third quarter of 2025, annual impairment tests were completed at all of our reporting units that carried a goodwill balance as of July 1, 2025. No impairments resulted from these tests.

Other Indefinite-Lived Intangible Assets

At December 31, 2025 and 2024, we had $44.4 million and $29.3 million, respectively, of other indefinite-lived intangible assets included in other long-term assets on our balance sheets. These assets consist of $24.1 million of spectrum frequencies, which enable our utilities to transmit data and voice communications over a wavelength dedicated to us throughout our service territories. We also have $5.2 million of other indefinite-lived intangible assets, consisting of a MGU trade name from a previous acquisition. In October 2025, we entered into an option agreement for exclusive rights to purchase land for future generation development in Wisconsin. We made the first annual option payment and incurred costs of $15.1 million during 2025, with a right to exercise our option on or before December 31, 2030.

Finite-Lived Intangible Asset

At December 31, 2025 and 2024, we had a finite-lived intangible asset with a gross carrying amount of $18.8 million and $13.0 million, respectively, related to a PPA for Maple Flats acquired by WECI in November 2024. The PPA will be amortized over a useful life of 15 years and expires in 2039. At December 31, 2025 and 2024, accumulated amortization related to the intangible asset was not material. This finite-lived intangible asset is included in other long-term assets on our balance sheet. Amortization expense related to the intangible asset was not material for the year ended December 31, 2025 and 2024. Amortization expense to be recorded as a decrease to operating revenues is expected to be $1.3 million in each of the next five years. See Note 2, Acquisitions, for more information on the acquisition of Maple Flats.

Intangible Liabilities

The intangible liabilities below were all obtained through acquisitions by WECI.
December 31, 2025December 31, 2024
(in millions)Gross Carrying AmountAccumulated AmortizationNet Carrying AmountGross Carrying AmountAccumulated AmortizationNet Carrying Amount
PPAs (1)
$751.2 $(176.5)$574.7 $679.6 $(119.3)$560.3 
Proxy revenue swap (2)
7.2 (4.9)2.3 7.2 (4.2)3.0 
Interconnection agreements (3)
4.7 (1.4)3.3 4.7 (1.2)3.5 
Total intangible liabilities$763.1 $(182.8)$580.3 $691.5 $(124.7)$566.8 

(1)    Represents PPAs related to the acquisition of Blooming Grove, Tatanka Ridge, Jayhawk, Thunderhead, Samson I, Sapphire Sky, Delilah I, and Hardin III expiring between 2030 and 2040. The weighted-average remaining useful life of the PPAs is 10 years. See Note 2, Acquisitions, for more information on recent WECI acquisitions.

(2)    Represents an agreement with a counterparty to swap the market revenue of Upstream's wind generation for fixed quarterly payments over 10 years, which expires in 2029. The remaining useful life of the proxy revenue swap is three years.
(3)    Represents interconnection agreements related to the acquisitions of Tatanka Ridge and Bishop Hill III, expiring in 2040 and 2041, respectively. These agreements relate to payments for connecting our facilities to the infrastructure of another utility to facilitate the movement of power onto the electric grid. The weighted-average remaining useful life of the interconnection agreements is 15 years.

Amortization related to these intangible liabilities for the years ended December 31, 2025, 2024, and 2023 was $58.1 million, $53.7 million, and $50.6 million, respectively. Amortization for the next five years is estimated to be:
For the Years Ending December 31
(in millions)20262027202820292030
Amortization to be recorded as an increase to operating revenues$59.9 $59.9 $59.9 $59.9 $59.9 
Amortization to be recorded as a decrease to other operation and maintenance0.2 0.2 0.2 0.2 0.2 
v3.25.4
Common Equity
12 Months Ended
Dec. 31, 2025
Stockholders' Equity Note [Abstract]  
COMMON EQUITY COMMON EQUITY
Stock-Based Compensation

The following table summarizes our pre-tax stock-based compensation expense and the related tax benefit recognized in income for the years ended December 31:
(in millions)202520242023
Stock options$4.1 $4.9 $5.3 
Restricted stock6.2 7.6 6.6 
Performance units37.9 26.8 (2.2)
(1)
Stock-based compensation expense$48.2 $39.3 $9.7 
Related tax benefit$13.2 $10.8 $2.7 

(1)    The reduction in expense was due to a decrease in the fair value of the outstanding performance units.

Stock-based compensation costs capitalized during 2025, 2024, and 2023 were not significant.

Stock Options

The following is a summary of our stock option activity during 2025:
Stock OptionsNumber of OptionsWeighted-Average Exercise Price
Weighted-Average Remaining Contractual Life
(in years)
Aggregate Intrinsic Value (in millions)
Outstanding as of January 1, 20252,916,902 $82.32 
Granted231,024 94.55 
Exercised(575,758)67.92 
Forfeited(1,351)91.11 
Expired(1,330)52.90 
Outstanding as of December 31, 20252,569,487 86.65 5.3$48.3 
Exercisable as of December 31, 20251,937,953 85.29 4.4$39.1 

The aggregate intrinsic value of outstanding and exercisable options in the above table represents the total pre-tax intrinsic value that would have been received by the option holders had they exercised all of their options on December 31, 2025. This is calculated as the difference between our closing stock price on December 31, 2025, and the option exercise price, multiplied by the number of in-the-money stock options. The intrinsic value of options exercised during the years ended December 31, 2025, 2024, and 2023 was $22.8 million, $11.2 million, and $5.2 million, respectively. The tax benefit from option exercises for the same years was approximately $6.3 million, $3.1 million, and $1.4 million, respectively. These amounts do not account for the compensation limitations under Internal Revenue Code Section 162(m).

As of December 31, 2025, approximately $1.4 million of unrecognized compensation cost related to unvested and outstanding stock options was expected to be recognized over the next 1.7 years on a weighted-average basis.
During the first quarter of 2026, the Compensation Committee awarded 269,085 non-qualified stock options with a weighted-average exercise price of $106.09 and a weighted-average grant date fair value of $21.20 per option to certain of our officers and other key employees under its normal schedule of awarding long-term incentive compensation.

Restricted Shares

The following restricted stock activity occurred during 2025:
Restricted SharesNumber of SharesWeighted-Average Grant Date Fair Value
Outstanding and unvested as of January 1, 2025105,242 $87.61 
Granted79,170 94.55 
Released(58,725)88.48 
Forfeited(6,774)90.88 
Outstanding and unvested as of December 31, 2025118,913 91.61 

The intrinsic value of restricted stock released was $5.7 million, $8.6 million, and $5.8 million for the years ended December 31, 2025, 2024, and 2023, respectively. The tax benefit from released restricted shares for the same years was $1.6 million, $2.4 million, and $1.6 million, respectively. These amounts do not account for the compensation limitations under Internal Revenue Code Section 162(m).

As of December 31, 2025, approximately $4.9 million of unrecognized compensation cost related to unvested and outstanding restricted stock was expected to be recognized over the next 1.7 years on a weighted-average basis.

During the first quarter of 2026, the Compensation Committee awarded 75,222 restricted shares to certain of our directors, officers, and other key employees under its normal schedule of awarding long-term incentive compensation. The grant date fair value of these awards was $106.09 per share.

Performance Units

During 2025, 2024, and 2023, the Compensation Committee awarded 185,945; 205,051; and 157,035 performance units, respectively, to officers and other key employees under the WEC Energy Group Performance Unit Plan.

Performance units with an intrinsic value of $15.4 million, $2.4 million, and $10.2 million were settled during 2025, 2024, and 2023, respectively. The tax benefit from the distribution of performance units for the same years was $3.8 million, $0.6 million, and $2.6 million, respectively.

At December 31, 2025, we had 502,733 performance units outstanding, including dividend equivalents. A liability of $57.1 million was recorded on our balance sheet at December 31, 2025 related to these outstanding units. As of December 31, 2025, approximately $31.3 million of unrecognized compensation cost related to unvested and outstanding performance units was expected to be recognized over the next 1.7 years on a weighted-average basis.

During the first quarter of 2026, we settled performance units with an intrinsic value of $25.2 million. The tax benefit from the distribution of these awards was $5.7 million. This amount and the tax benefits disclosed above do not account for the compensation limitations under Internal Revenue Code Section 162(m). In January 2026, the Compensation Committee also awarded 182,146 performance units to certain of our officers and other key employees under its normal schedule of awarding long-term incentive compensation.

Restrictions

Our ability as a holding company to pay common stock dividends primarily depends on the availability of funds received from our utility subsidiaries, We Power, Bluewater, ATC Holding, and WECI. Various financing arrangements and regulatory requirements impose certain restrictions on the ability of our subsidiaries to transfer funds to us in the form of cash dividends, loans, or advances. All of our utility subsidiaries, with the exception of UMERC and MGU, are prohibited from loaning funds to us, either directly or indirectly.
In accordance with their most recent rate orders, WE, WPS, and WG may not pay common dividends above the test year forecasted amounts reflected in their respective rate cases, if it would cause their average common equity ratio, on a financial basis, to fall below their authorized level of 53.0%. A return of capital in excess of the test year amount can be paid by each company at the end of the year provided that their respective average common equity ratios do not fall below the authorized level.

WE may not pay common dividends to us under WE's Restated Articles of Incorporation if any dividends on its outstanding preferred stock have not been paid. In addition, pursuant to the terms of WE's 3.60% Serial Preferred Stock, WE's ability to declare common dividends would be limited to 75% or 50% of net income during a 12-month period if its common stock equity to total capitalization, as defined in the preferred stock designation, is less than 25% and 20%, respectively.

NSG's long-term debt obligations contain provisions and covenants restricting the payment of cash dividends and the purchase or redemption of its capital stock.

The long-term debt obligations of UMERC, Bluewater Gas Storage, and ATC Holding contain a provision requiring them to maintain a total funded debt to capitalization ratio of 65% or less.

The long-term debt obligations of WECI Wind Holding I, WECI Wind Holding II, and WECI Energy Holding III contain various conditions that must be met prior to them making any cash distributions. Included in these provisions is a requirement to maintain a debt service coverage ratio of 1.2 or greater prior to the distribution.

WEC Energy Group has the option to defer interest payments on its 2024A Junior Notes, 2024B Junior Notes, and 2025 Junior Notes, from time to time, for one or more periods of up to 10 consecutive years per period. During any period in which it defers interest payments, it may not declare or pay any dividends or distributions on, or redeem, repurchase or acquire, its common stock.

See Note 13, Short-Term Debt and Lines of Credit, for discussion of certain financial covenants related to short-term debt obligations.

As of December 31, 2025, restricted net assets of our consolidated subsidiaries totaled approximately $14 billion. Our equity in undistributed earnings of investees accounted for by the equity method was approximately $615 million.

We do not believe that these restrictions will materially affect our operations or limit any dividend payments in the foreseeable future.

Common Stock

As of January 1, 2024, we began issuing new shares of common stock to fulfill our obligations under various stock-based employee benefit and compensation plans and to provide shares to participants in our dividend reinvestment and stock purchase plan. During 2023, we instructed our independent agents to purchase shares on the open market to fulfill obligations under these plans. As such, no new shares of common stock were issued during the year ended December 31, 2023.

In August 2024, we entered into an EDA, under which we could offer and sell, from time to time, shares of our common stock having an aggregate sales price of up to $1.5 billion through an at-the-market offering program, which included an equity forward sales component. This EDA was terminated on October 31, 2025. Prior to its termination, we issued 7,610,457 shares of common stock under this EDA and received proceeds of $797.3 million, which was net of $9.2 million of commissions and other fees. We did not enter into any forward sales agreements under the August 2024 EDA.

In connection with our termination of the August 2024 EDA, we entered into a new EDA on October 31, 2025, under which we may offer and sell, from time to time, shares of our common stock having an aggregate sales price of up to $3.0 billion through an at-the-market offering program, which also includes an equity forward sales component and a collared forward sales component. We may offer and sell our common shares through the sales agents party to the EDA during the term of the agreement. The October 2025 EDA will terminate upon the earliest of (i) the sale of all common stock subject to the EDA, (ii) termination of the EDA pursuant to its terms, or (iii) October 31, 2028. Actual sales of common stock under the EDA will depend on a variety of factors, including market conditions, the trading price of our common stock, capital needs, and our determination of the appropriate sources of funding. As of December 31, 2025, we had not issued any shares of common stock under the October 2025 EDA.
In November 2025, we entered into a forward sales contract pursuant to our October 2025 EDA. Pursuant to the terms of the contract, 58,533 shares were sold with an initial forward price of $110.7748 per share. The initial forward price is subject to adjustment on a daily basis based on a floating interest rate factor and will decrease by other fixed amounts as specified in the contract. No amounts are recorded on our balance sheet with respect to this contract until actual settlement occurs. The contract requires us to, at our election on or before June 30, 2027, either (i) physically settle the transaction by issuing shares of our stock in exchange for net cash proceeds at the then-applicable forward sales price or (ii) net settle the transaction through the delivery or receipt of cash or shares in accordance with the contract provisions. As of December 31, 2025, no shares were settled under this contract. At December 31, 2025, we could have settled this forward sales contract with physical delivery of 58,533 shares of common stock to the counterparties in exchange for cash proceeds of $6.5 million. The forward sales contract could have alternatively been settled with delivery of approximately $0.3 million of cash or approximately 3,084 shares of common stock to us, if we had elected to net cash or net share settle, respectively, at December 31, 2025.

Any shares offered and sold under our EDAs were done pursuant to our registration statement on Form S-3 filed with the SEC on August 5, 2024 and the related prospectus supplements.

We had the following changes to our outstanding common stock during the years ended December 31, 2025 and 2024:
20252024
Common stock shares outstanding at beginning of period317,680,855 315,434,531 
Shares issued:
At-the-market offering program6,579,783 1,030,674 
Stock-based compensation 609,995 455,474 
401(k)247,889 336,800 
Stock investment plan342,997 423,376 
Common stock shares outstanding at end of period325,461,519 317,680,855 

The following is a summary of shares purchased to fulfill exercised stock options and restricted stock awards during the years ended December 31:
(in millions, except share amounts)202520242023
Shares purchased13,795 23,292 182,795 
Cost of shares purchased$1.3 $3.2 $16.6 

During the year ended December 31, 2025, our Board of Directors declared common stock dividends which are summarized below:
Date DeclaredDate PayablePer SharePeriod
January 16, 2025March 1, 2025$0.8925First quarter
April 17, 2025June 1, 2025$0.8925Second quarter
July 17, 2025September 1, 2025$0.8925Third quarter
October 16, 2025December 1, 2025$0.8925Fourth quarter

On January 22, 2026, our Board of Directors declared a quarterly cash dividend of $0.9525 per share, which equates to an annual dividend of $3.81 per share. The dividend is payable on March 1, 2026, to shareholders of record on February 13, 2026.
Earnings Per Share

The following table shows the computation of our basic and diluted EPS for the years ended December 31:
(in millions, except per share amounts)202520242023
Numerator:
Net income attributed to common shareholders$1,557.5 $1,527.2 $1,331.7 
Denominator:
Weighted average basic shares outstanding321.9316.2315.4
Dilutive effect of stock-based compensation awards0.6 0.3 0.5 
Dilutive effect of convertible senior notes1.3 — — 
Weighted average diluted shares323.8 316.5 315.9 
Basic EPS$4.84 $4.83 $4.22 
Diluted EPS$4.81 $4.83 $4.22 
v3.25.4
Preferred Stock
12 Months Ended
Dec. 31, 2025
Class of Stock Disclosures [Abstract]  
PREFERRED STOCK PREFERRED STOCK
The following table shows preferred stock authorized and outstanding at December 31, 2025 and 2024:
(in millions, except share and per share amounts)Shares AuthorizedShares OutstandingRedemption Price Per ShareTotal
WEC Energy Group
$0.01 par value Preferred Stock
15,000,000   $ 
WE
$100 par value, Six Per Cent. Preferred Stock
45,000 44,498  4.4 
$100 par value, Serial Preferred Stock 3.60% Series
2,286,500 260,000 $101 26.0 
$25 par value, Serial Preferred Stock
5,000,000    
WPS
$100 par value, Preferred Stock
1,000,000    
PGL
$100 par value, Cumulative Preferred Stock
430,000    
NSG
$100 par value, Cumulative Preferred Stock
160,000    
Total$30.4 
v3.25.4
Short-Term Debt and Lines of Credit
12 Months Ended
Dec. 31, 2025
Short-Term Debt [Abstract]  
SHORT-TERM DEBT AND LINES OF CREDIT SHORT-TERM DEBT AND LINES OF CREDIT
The following table shows our short-term borrowings and their corresponding weighted-average interest rates as of December 31:
(in millions, except percentages)20252024
Commercial paper
Amount outstanding at December 31$1,921.3 $1,114.4 
Average interest rate on amounts outstanding at December 313.89 %4.63 %
Operating expense loans
Amount outstanding at December 31 (1)
$3.4 $2.2 

(1)    Coyote Ridge, Tatanka Ridge, Samson I, and Jayhawk have entered into operating expense loans. In accordance with their limited liability company operating agreements, they received loans from the holders of their noncontrolling interests in proportion to their ownership interests.
Our average amount of commercial paper borrowings based on daily outstanding balances during 2025, was $1,124.2 million with a weighted-average interest rate during the period of 4.43%.

WEC Energy Group, WE, PGL, WPS, and WG have entered into bank back-up credit facilities to maintain short-term credit liquidity which, among other terms, require them to maintain, subject to certain exclusions, a total funded debt to capitalization ratio of 70.0%, 65.0%, 65.0%, 65.0%, and 65.0% or less, respectively. As of December 31, 2025, all companies were in compliance with their respective ratio.

The information in the table below relates to our revolving credit facilities used to support our commercial paper borrowing programs, including remaining available capacity under these facilities as of December 31:
(in millions)Maturity2025
Revolving credit facility (WEC Energy Group) (1) (2) (3)
August 2030$1,700.0 
Revolving credit facility (WE) (1) (2)
August 2030800.0 
Revolving credit facility (PGL) (1) (2)
August 2030600.0 
Revolving credit facility (WPS) (1) (2)
August 2030450.0 
Revolving credit facility (WG) (1) (4)
August 2030350.0 
Total short-term credit capacity $3,900.0 
Less:  
Letters of credit issued inside credit facilities $2.3 
Commercial paper outstanding 1,921.3 
Available capacity under existing facilities $1,976.4 

(1)    These revolving credit facilities have a renewal provision for two extensions, subject to lender approval. Each extension is for a period of one year.

(2)    In August 2025, the capacity of the credit facilities for each of WEC Energy Group, WE, PGL, and WPS was increased to $1,700.0 million, $800.0 million, $600.0 million, and $450.0 million, respectively, and the maturity for each facility was extended to August 2030.

(3)    In August 2025, WEC Energy Group terminated its $200.0 million bilateral credit facility.

(4)    In August 2025, WG extended the maturity of its credit facility to August 2030.

The bank back-up credit facilities contain customary covenants, including certain limitations on the respective companies' ability to sell assets. The credit facilities also contain customary events of default, including payment defaults, material inaccuracy of representations and warranties, covenant defaults, bankruptcy proceedings, certain judgments, Employee Retirement Income Security Act of 1974 defaults, and change of control. In addition, pursuant to the terms of WEC Energy Group's credit agreement, we must ensure that certain of our subsidiaries comply with several of the covenants contained therein.
v3.25.4
Long-Term Debt
12 Months Ended
Dec. 31, 2025
Debt Disclosure [Abstract]  
LONG-TERM DEBT LONG-TERM DEBT
The following table is a summary of our long-term debt outstanding as of December 31:
20252024
(in millions)Maturity DateWeighted Average Interest RateBalanceWeighted Average Interest RateBalance
WEC Energy Group Senior Notes (unsecured)2026-20333.96 %$6,325.0 4.13 %$6,045.0 
WEC Energy Group Junior Notes (unsecured) (1) (2)
2055-20566.24 %1,350.0 6.72 %750.0 
WE Debentures (unsecured)2028-20954.55 %4,485.0 4.55 %3,935.0 
WEPCo Environmental Trust (secured, nonrecourse) (5) (10)
2026-20351.58 %78.8 1.58 %88.0 
WPS Senior Notes (unsecured)2028-20513.99 %1,975.0 4.17 %2,275.0 
WG Debentures (unsecured)2028-20464.34 %940.0 3.92 %840.0 
PGL First and Refunding Mortgage Bonds (secured) (3)
2027-20473.56 %1,995.0 3.56 %1,995.0 
NSG First Mortgage Bonds (secured) (4)
2027-20433.81 %177.0 3.81 %177.0 
MERC Senior Notes (unsecured)2027-20473.64 %210.0 3.04 %210.0 
MGU Senior Notes (unsecured)2027-20474.38 %190.0 3.45 %175.0 
UMERC Senior Notes (unsecured)2029-20354.23 %280.0 3.26 %160.0 
Bluewater Gas Storage Senior Notes (unsecured) (5)
2026-20474.07 %128.0 4.07 %131.9 
ATC Holding Senior Notes (unsecured)2028-20304.02 %390.0 4.05 %475.0 
We Power Subsidiaries Notes (secured, nonrecourse) (5) (6)
2026-20415.71 %769.9 5.67 %814.3 
WECC Notes (unsecured)20286.94 %50.0 6.94 %50.0 
WECI Wind Holding I Senior Notes (secured, nonrecourse) (5) (7)
2026-20322.75 %202.1 2.75 %246.4 
WECI Wind Holding II Senior Notes (secured, nonrecourse) (5) (8)
2026-20316.38 %147.9 6.38 %167.6 
WECI Energy Holding III Senior Notes (secured, nonrecourse) (5) (9)
2026-20395.73 %446.2 5.73 %488.7 
Total 20,139.9 19,023.9 
Jayhawk acquisition7.5 7.5 
Unamortized debt issuance costs(110.4)(103.2)
Unamortized discount, net and other(19.5)(21.1)
Total long-term debt, including current portion20,017.5 18,907.1 
Current portion of long-term debt(1,519.4)(1,729.0)
Total long-term debt$18,498.1 $17,178.1 

(1)    In November 2025, we issued our 2025 Junior Notes. Our 2025 Junior Notes are fixed-to-fixed reset rate junior subordinated notes. The rate for our 2025 Junior Notes was 5.625% as of December 31, 2025. The rate for our 2025 Junior Notes will reset on May 15, 2031; provided the reset rate will not be less than 5.625%.

(2)    In December 2024, we issued our 2024A Junior Notes and 2024B Junior Notes. Our 2024A Junior Notes and 2024B Junior Notes are fixed-to-fixed reset rate junior subordinated notes. The rate for our 2024A Junior Notes was 6.69% as of December 31, 2025. The rate for our 2024A Junior Notes will reset on June 15, 2030. The rate for our 2024B Junior Notes was 6.74% as of December 31, 2025. The rate for our 2024B Junior Notes will reset on June 15, 2035.

(3)    PGL's First Mortgage Bonds are subject to the terms and conditions of PGL's First Mortgage Indenture dated January 2, 1926, as supplemented. Under the terms of the Indenture, substantially all property owned by PGL is pledged as collateral for these outstanding debt securities.

PGL has used certain First Mortgage Bonds to secure tax exempt interest rates. The Illinois Finance Authority has issued Tax Exempt Bonds, and the proceeds from the sale of these bonds were loaned to PGL. In return, PGL issued $100 million of collateralized First Mortgage Bonds.

(4)    NSG's First Mortgage Bonds are subject to the terms and conditions of NSG's First Mortgage Indenture dated April 1, 1955, as supplemented. Under the terms of the Indenture, substantially all property owned by NSG is pledged as collateral for these outstanding debt securities.

(5)    The long-term debt of Bluewater, WECI Wind Holding I, WECI Wind Holding II, WECI Energy Holding III, WEPCo Environmental Trust, and We Power's subsidiaries requires periodic principal payments.

(6)    We Power's subsidiaries' senior notes are secured by a collateral assignment of the leases between We Power's subsidiaries and WE related to PWGS and ERGS, as applicable.
(7)    WECI Wind Holding I's Senior Notes are secured by a first priority security interest in the ownership interest of its subsidiaries, as well as a pledge of equity in WECI Wind Holding I.

(8)    WECI Wind Holding II's Senior Notes are secured by a first priority security interest in the ownership interest of its subsidiaries, as well as a pledge of equity in WECI Wind Holding II.

(9)    WECI Energy Holding III's Senior Notes are secured by a first priority security interest in the ownership interest of its subsidiaries, as well as a pledge of equity in WECI Energy Holding III.

(10)    WEPCo Environmental Trust’s ETBs are secured by a pledge of and lien on environmental control property, which includes the right to impose, collect and receive a non-bypassable environmental control charge paid by all of WE's retail electric distribution customers, the right to obtain true-up adjustments of the environmental control charges, and all revenues or other proceeds arising from those rights and interests. See Note 23, Variable Interest Entities, for more information.

We amortize debt premiums, discounts, and debt issuance costs over the life of the debt and we include the costs in interest expense.

In December 2024, the DOE issued to WE a conditional commitment for a federal loan guarantee for up to $2.5 billion of borrowings that would be used by WE to fund a portion of the costs to construct certain utility-scale renewable generation projects. The conditional commitment was issued pursuant to provisions of the IRA. Under the conditional commitment, the guaranteed borrowings would be senior, unsecured borrowings of WE made through the Federal Financing Bank and reduce WE's issuance of senior, unsecured obligations in the capital markets. Final approval and issuance of a loan guarantee by the DOE is subject to numerous conditions, including negotiation of definitive agreements, completion of due diligence by the DOE, receipt of any necessary regulatory approvals, and the satisfaction of other conditions. While we continue to work with the DOE, there can be no assurance that the DOE will issue the loan guarantee for WE.

WEC Energy Group, Inc.

In June 2025, the remaining $120.0 million outstanding of our 3.55% Senior Notes, due June 15, 2025, matured, and principal and accrued interest were paid with proceeds received from issuing commercial paper.

In September 2025, our $500.0 million of 5.00% Senior Notes due September 27, 2025, matured, and principal and accrued interest were paid with proceeds received from issuing commercial paper.

In November 2025, we issued $600.0 million of 5.625% 2025 Junior Notes due May 15, 2056, and used the net proceeds to repay short-term debt and for other general corporate purposes.

In January 2026, our $1,000.0 million of 4.75% Senior Notes due January 9, 2026, matured, and principal and accrued interest were paid with proceeds received from issuing commercial paper.

Convertible Senior Notes

2028 Notes

In June 2025, we issued $900.0 million of 2028 Notes. The 2028 Notes are senior unsecured obligations and bear interest at an annual rate of 3.375%, payable semiannually beginning on December 1, 2025. Proceeds from the offering were used to repay short-term debt and for other general corporate purposes.

The 2028 Notes will mature on June 1, 2028, unless earlier converted or repurchased in accordance with their terms. No sinking fund is provided for the 2028 Notes. Upon the occurrence of a fundamental change, as defined in the related indenture, holders may require us to repurchase for cash all or any portion of their 2028 Notes. We may not redeem the 2028 Notes prior to their maturity date. Any fundamental change repurchases of the 2028 Notes will be at a price equal to 100% of the principal amount, plus accrued and unpaid interest.
Holders may convert all or any portion of their notes at their option at any time prior to the close of business on the business day immediately preceding March 1, 2028, only under the following circumstances:

During any calendar quarter commencing after the calendar quarter ending on September 30, 2025, (and only during such calendar quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price of such series of notes on each applicable trading day;

During the five consecutive business day period immediately after any ten consecutive trading day period (measurement period) in which the trading price per $1,000 principal amount of notes, as determined following a request by a holder or holders, for each trading day of the measurement period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate of such series of notes on each such trading day; or

Upon the occurrence of specified corporate events, as defined in the related indenture.

Holders may convert all or any portion of their notes at any time, regardless of the foregoing circumstances, on or after March 1, 2028, until the close of business on the second scheduled trading day immediately preceding the maturity date.

Upon conversion, we will pay cash up to the aggregate principal amount of the notes to be converted and pay or deliver cash, shares of our common stock, or a combination of cash and shares of our common stock, at our election, in respect of the remainder, if any, of our conversion obligation in excess of the aggregate principal amount of the notes being converted.

The initial conversion rate for the 2028 Notes is 7.7901 shares of common stock per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $128.37 per share of our common stock. The conversion rate is subject to adjustment upon the occurrence of certain specified events, as defined in the related indenture, but will not be adjusted for any accrued and unpaid interest. In addition, upon the occurrence of a make-whole fundamental change, as defined in the related indenture, we will, in certain circumstances, increase the conversion rate by a number of additional shares of common stock for conversions in connection with the make-whole fundamental change.

2027 Notes and 2029 Notes

In the second quarter of 2024, we issued $862.5 million of 2027 Notes and $862.5 million of 2029 Notes. The 2027 Notes and 2029 Notes are senior unsecured obligations and bear interest at an annual rate of 4.375%, payable semiannually beginning on December 1, 2024. Proceeds from the offerings were used to repay short-term debt and for general corporate purposes.

The 2027 Notes will mature on June 1, 2027, and the 2029 Notes will mature on June 1, 2029, unless earlier converted or repurchased in accordance with their terms, or in the case of the 2029 Notes, redeemed by us. No sinking fund is provided for either series of the notes. Upon the occurrence of a fundamental change, as defined in the related indenture, holders may require us to repurchase for cash all or any portion of their 2027 or 2029 Notes. We may not redeem the 2027 Notes prior to their maturity date. We may redeem for cash all or part of the 2029 Notes, at our option, on or after June 1, 2027 and on or before the 41st scheduled trading day immediately preceding their maturity date, if the last reported sale price per share of our common stock has been at least 130% of the conversion price of the 2029 Notes then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period. Any redemptions or fundamental change repurchases of the 2027 Notes or 2029 Notes will be at a price equal to 100% of the principal amount, plus accrued and unpaid interest.

Holders may convert all or any portion of their notes at their option at any time prior to the close of business on the business day immediately preceding March 1, 2027, in the case of the 2027 Notes, and March 1, 2029, in the case of the 2029 Notes, only under the following circumstances:

During any calendar quarter commencing after the calendar quarter ending on September 30, 2024 (and only during such calendar quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price of such series of notes on each applicable trading day;

During the five consecutive business day period immediately after any ten consecutive trading day period (measurement period) in which the trading price per $1,000 principal amount of notes of such series for each trading day of the measurement period
was less than 98% of the product of the last reported sale price of our common stock and the conversion rate of such series of notes on each such trading day;

Upon the occurrence of specified corporate events, as defined in the related indenture;

In the case of the 2029 Notes only, if we call any of the 2029 Notes for redemption, at any time prior to the close of business on the second scheduled trading day prior to the redemption date, but only with respect to the 2029 Notes called (or deemed called) for redemption.

Holders may convert all or any portion of their notes at any time, regardless of the foregoing circumstances, on or after March 1, 2027, in the case of the 2027 Notes, or March 1, 2029, in the case of the 2029 Notes, until the close of business on the second scheduled trading day immediately preceding the maturity date of such series of notes.

Upon conversion, we will pay cash up to the aggregate principal amount of the notes to be converted and pay or deliver cash, shares of our common stock, or a combination of cash and shares of our common stock, at our election, in respect of the remainder, if any, of our conversion obligation in excess of the aggregate principal amount of the notes being converted.

The initial conversion rate for both the 2027 Notes and 2029 Notes is 10.1243 shares of common stock per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $98.77 per share of our common stock. The conversion rate is subject to adjustment upon the occurrence of certain specified events, as defined in the related indenture, but will not be adjusted for accrued and unpaid interest. In addition, upon the occurrence of a make-whole fundamental change, as defined in the related indenture, we will, in certain circumstances, increase the conversion rate by a number of additional shares of common stock for conversions in connection with the make-whole fundamental change.

As of December 31, 2025, the conditions allowing holders to convert their notes were not met. In accordance with the guidance in ASC Subtopic 470-20, Debt – Debt with Conversion and Other Options, the 2027 Notes, 2028 Notes, and 2029 Notes were accounted for in their entirety as a liability on our balance sheet. The following is a summary of our convertible debt instruments as of December 31, 2025:
(in millions)
Principal Amount
Unamortized Debt Issuance Costs
Net Carrying Amount
Fair Value Amount (1)
2027 Notes
$862.5 $(4.7)$857.8 $977.8 
2028 Notes900.0 (8.5)891.5 912.6 
2029 Notes
862.5 (6.8)855.7 1,011.7 

(1)    The fair values are categorized in Level 2 of the fair value hierarchy. See Note 1(r), Fair Value Measurements, for more information on the levels of the fair value hierarchy.

The following table provides a summary of the interest expense recorded for each of the 2027 Notes, 2028 Notes, and 2029 Notes for the year ended December 31:
(in millions)20252024
2027 Notes
Contractual interest expense
$37.7 $22.3 
Amortization of debt issuance costs
3.3 1.9 
Total interest expense – 2027 Notes41.0 24.2 
2028 Notes
Contractual interest expense$17.0 $— 
Amortization of debt issuance costs1.8 — 
Total interest expense – 2028 Notes18.8 — 
2029 Notes
Contractual interest expense
37.7 22.3 
Amortization of debt issuance costs
2.0 1.2 
Total interest expense – 2029 Notes$39.7 $23.5 
Wisconsin Electric Power Company

In June 2025, WE's $250.0 million of 3.10% Debentures, due June 1, 2025, matured, and outstanding principal and accrued interest were paid with proceeds received from issuing commercial paper.

In September 2025, WE issued $500.0 million of 4.15% Debentures, due October 15, 2030, and used the net proceeds to repay short-term debt and for other general corporate purposes.

In December 2025, WE issued $300.0 million of 3.95% Debentures, due March 1, 2029, and used the net proceeds to repay short-term debt and for other general corporate purposes.

Wisconsin Public Service Corporation

In November 2025, WPS's $300.0 million of 5.35% Senior Notes, due November 10, 2025, matured, and outstanding principal and accrued interest were paid with proceeds received from issuing commercial paper.

In January 2026, WPS issued $300.0 million of 4.25% Senior Notes, due January 15, 2031, and used the net proceeds to repay short-term debt and for other general corporate purposes.

Wisconsin Gas LLC

In September 2025, WG issued $175.0 million of 4.70% Debentures, due October 1, 2030, and $125.0 million of 5.39% Debentures, due October 1, 2035, and used the net proceeds to repay $200.0 million of WG's 3.53% Debentures that matured on September 30, 2025, and to repay short-term debt and for other general limited liability company purposes.

Minnesota Energy Resources Corporation

In April 2025, MERC issued $50.0 million of 5.20% Senior Notes, due May 1, 2030, and used the net proceeds to repay MERC's $50.0 million of 2.69% Senior Notes that matured on May 1, 2025.

Michigan Gas Utilities Corporation

In April 2025, MGU issued $75.0 million of 5.20% Senior Notes, due May 1, 2030, and used the net proceeds to repay MGU's $60.0 million of 2.69% Senior Notes that matured on May 1, 2025 and intercompany short-term debt to its parent, Integrys.

Upper Michigan Energy Resources Corporation

In August 2025, UMERC issued $80.0 million of 5.31% Senior Notes, due August 14, 2030, and $40.0 million of 5.93% Senior Notes, due August 14, 2035, and used the net proceeds to repay intercompany short-term debt to its parent, WEC Energy Group, and for other general corporate purposes.

ATC Holding LLC

In December 2025, ATC's $85.0 million of 4.18% Debentures, due December 20, 2025, matured, and outstanding principal and accrued interest were paid with a contribution received from WEC Energy Group.
Maturities of Long-Term Debt Outstanding

The following table shows the long-term debt securities maturing within one year of December 31, 2025:
(in millions)Interest Rate
Maturity Date (1)
Principal Amount
WEC Energy Group Senior Notes (unsecured)4.75%January$1,000.0 
WEC Energy Group Senior Notes (unsecured)5.60%September350.0 
WEPCo Environmental Trust (secured, nonrecourse)1.58%Semi-annually9.3 
Bluewater Gas Storage Senior Notes (unsecured)3.76%Semi-annually3.1 
Bluewater Gas Storage Senior Notes (unsecured)5.41%Semi-annually1.0 
We Power Subsidiaries Notes – PWGS (secured, nonrecourse) 4.91%Monthly8.9 
We Power Subsidiaries Notes – ERGS (secured, nonrecourse)5.209%Semi-annually17.1 
We Power Subsidiaries Notes – ERGS (secured, nonrecourse) 4.673%Semi-annually12.8 
We Power Subsidiaries Notes – PWGS (secured, nonrecourse)6.00%Monthly7.9 
WECI Wind Holding I Senior Notes (secured, nonrecourse)2.75%Semi-annually45.1 
WECI Wind Holding II Senior Notes (secured, nonrecourse)6.38%Semi-annually22.6 
WECI Energy Holding III Senior Notes (secured, nonrecourse)5.73%Semi-annually41.6 
Total $1,519.4 

(1)    Maturity dates listed as semi-annually and monthly are associated with debt that requires periodic principal payments.

The following table shows the future maturities of our long-term debt outstanding as of December 31, 2025:
(in millions)Payments
2026$1,519.4 
20272,137.3 
20283,203.2 
20292,943.4 
20301,691.9 
Thereafter8,644.7 
Total$20,139.9 

Certain long-term debt obligations contain financial and other covenants related to payment of principal and interest when due, maintaining certain total funded debt to capitalization ratios, and various other obligations. Failure to comply with these covenants could result in an event of default, which could result in the acceleration of outstanding debt obligations.
v3.25.4
Leases
12 Months Ended
Dec. 31, 2025
Leases [Abstract]  
LEASES LEASES
In accordance with ASC Subtopic 980-842, Regulated Operations – Leases (Subtopic 980-842), the timing of expense recognition associated with our leases is modified to conform to the rate treatment. The difference between the lease expense that is allowed for rate-making purposes and the unadjusted lease expense calculated under Topic 842 is deferred as a regulatory asset on our balance sheets. For our finance leases, amortization of the right-of-use asset is modified so that the total of the imputed interest and amortization costs equals the lease expense that is allowed for rate-making purposes in accordance with Subtopic 980-842.

Obligations Under Operating Leases

We have recorded right of use assets and lease liabilities primarily associated with the following operating leases:

Leases of office space, primarily related to several floors we are leasing in the Aon Center office building in Chicago, Illinois, through April 2039.
Land we are leasing related to our Rothschild biomass plant through June 2051.
Rail cars we are leasing to transport coal to various generating facilities through June 2027.
Land we are leasing related to our utility and non-utility solar generation projects through May 2075.

The operating leases generally require us to pay property taxes, insurance premiums, and operating and maintenance costs associated with the leased property. Certain of our leases contain options for early termination or to renew past the initial term, as
set forth in the lease agreements. These options are included in our calculation of the lease obligations if it is reasonably certain that they will be exercised.

Obligations Under Finance Leases

Land Leases – Utility Solar Generation

We have various land leases related to our investments in utility solar generation. Each lease has an initial term and one or more optional extensions. We expect the optional extensions to be exercised, and, as a result, all of the land leases are being amortized over an extended term which can range from 40 to 50 years. Once a solar project achieves commercial operation, the lease liability is remeasured to reflect the final total acres being leased. Our payments related to these leases are being recovered through rates.

Land Leases – Non-Utility Energy Infrastructure Solar Generation

We have various land leases related to our investments in non-utility solar generation. Each lease has an initial term and one or more optional extensions. We expect the optional extensions to be exercised, and, as a result, all of the land leases are being amortized over an extended term of approximately 50 years.

Amounts Recognized in the Financial Statements and Other Information

The components of lease expense and supplemental cash flow information related to our leases for the years ended December 31 are as follows:
(in millions)202520242023
Finance lease expense
Amortization of right of use assets (1)
$1.1 $0.2 $— 
Interest on lease liabilities (2)
6.9 1.8 0.8 
Operating lease expense (3)
7.8 5.2 4.7 
Short-term lease expense (3)
0.2 0.6 1.2 
Total lease expense$16.0 $7.8 $6.7 
Other information
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from finance leases$6.4 $1.8 $0.8 
Operating cash flows from operating leases7.5 7.1 6.8 
Financing cash flows from finance leases0.9 — — 
Non-cash activities
Right of use assets obtained in exchange for finance lease liabilities (4)
$63.8 $153.2 $32.8 
Right of use assets obtained in exchange for operating lease liabilities43.5 2.6 18.3 
Weighted-average remaining lease term – finance leases49.6 years50.2 years49.4 years
Weighted-average remaining lease term – operating leases35.8 years25.1 years22.4 years
Weighted-average discount rate – finance lease (5)
6.0 %5.9 %5.3 %
Weighted average discount rate – operating leases (5)
6.3 %5.9 %5.8 %

(1)    Amortization of right of use assets was included as a component of depreciation and amortization expense.

(2)    Interest on lease liabilities was included as a component of interest expense.

(3)    Operating and short-term lease expense were included as a component of other operation and maintenance expense.

(4)    Amounts are net of any reductions to right of use assets and finance lease liabilities resulting from remeasurements.

(5)    Because our leases do not provide an implicit rate of return, we used an estimate of the fully collateralized incremental borrowing rates based upon information available for similarly rated companies in determining the present value of lease payments.
The following table summarizes our finance and operating lease right of use assets and obligations at December 31:
(in millions)20252024Balance Sheet Location
Right of use assets
Operating lease right of use assets, net$69.5 $32.1 Other long-term assets
Finance lease right of use assets, net
Land leases – utility solar generation$291.5 $235.8 
Land leases –non-utility energy infrastructure solar generation42.3 43.5 
Other1.7 2.0 
Total finance lease right of use assets, net (1)
$335.5 $281.3 Property, plant, and equipment, net
Lease obligations
Current operating lease liabilities$3.1 $4.3 Other current liabilities
Long-term operating lease liabilities$73.0 $37.5 Other long-term liabilities
Current finance lease liabilities
Other$0.2 $0.2 Other current liabilities
Long-term finance lease liabilities
Land leases – utility solar generation$327.3 $257.9 
Land leases –non-utility energy infrastructure solar generation43.3 43.8 
Other1.4 1.6 
Total long-term finance lease liabilities$372.0 $303.3 Finance lease obligations

(1)    Amounts are net of accumulated amortization of $16.3 million and $10.0 million at December 31, 2025 and 2024, respectively.

Future minimum lease payments under our operating and finance leases and the present value of our net minimum lease payments as of December 31, 2025, were as follows:
(in millions)Total Operating LeasesLand Leases - Utility Solar GenerationLand Leases - Non-Utility Energy Infrastructure Solar GenerationOtherTotal Finance Leases
2026$7.0 $9.5 $2.2 $0.3 $12.0 
20276.3 13.8 2.3 0.3 16.4 
20285.2 15.9 2.3 0.1 18.3 
20295.2 16.2 2.3 0.1 18.6 
20305.0 16.6 2.4 0.1 19.1 
Thereafter208.2 1,221.0 156.6 2.5 1,380.1 
Total minimum lease payments236.9 1,293.0 168.1 3.4 1,464.5 
Less: Interest(160.8)(965.7)(124.8)(1.8)(1,092.3)
Present value of minimum lease payments76.1 327.3 43.3 1.6 372.2 
Less: Short-term lease liabilities(3.1)— — (0.2)(0.2)
Long-term lease liabilities$73.0 $327.3 $43.3 $1.4 $372.0 

As of February 20, 2026, we have not entered into any material leases that have not yet commenced.
v3.25.4
Income Taxes
12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Income Tax Disclosure INCOME TAXES
We adopted the new disclosure provisions of ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, effective January 1, 2025. See Note 1(q), Income Taxes, for more information on the adoption of this ASU.
Income Tax Expense

The following table is a summary of the components of income tax expense for the years ended December 31:
(in millions)202520242023
Current tax expense (benefit)
Federal$(242.5)$(178.5)$(36.7)
State(8.0)(128.5)21.9 
Deferred tax expense, net
Federal240.9 386.2 130.1 
State135.6 152.5 99.8 
ITCs, net(8.0)(9.7)(10.5)
Total income tax expense$118.0 $222.0 $204.6 

Statutory Rate Reconciliation

The provision for income taxes for each of the years ended December 31 differs from the amount of income tax determined by applying the applicable United States statutory federal income tax rate to income before income taxes as a result of the following:
202520242023
(in millions)AmountEffective Tax RateAmountEffective Tax RateAmountEffective Tax Rate
Income before income taxes
$1,673.5 $1,746.3 $1,536.3 
US federal statutory income tax rate
$351.9 21.0 %$367.3 21.0 %$322.6 21.0 %
State and local income taxes net of federal tax effect (1)
101.2 6.0 %108.0 6.2 %94.3 6.1 %
Tax credits
PTCs, net (2)
(261.3)(15.6)%(200.1)(11.5)%(168.2)(10.9)%
Other(8.2)(0.5)%(10.0)(0.6)%(10.9)(0.7)%
Nontaxable or nondeductible items
AFUDC-Equity (3)
(21.0)(1.3)%(12.6)(0.7)%(12.4)(0.8)%
Other11.0 0.7 %4.0 0.2 %4.4 0.2 %
Changes in unrecognized tax benefits
(2.0)(0.1)%(0.4)— %(1.8)(0.1)%
Other adjustments
Federal excess deferred tax amortization (4)
(43.0)(2.6)%(36.7)(2.1)%(37.6)(2.4)%
Other, net(10.6)(0.5)%2.5 0.2 %14.2 0.9 %
Total income tax expense$118.0 7.1 %$222.0 12.7 %$204.6 13.3 %

(1)    State taxes in Wisconsin made up the majority of the tax effect in this category.

(2)    PTCs are an inflation adjusted US federal income tax credit for each kilowatt hour of electricity generated by certain renewable energy projects.

(3)    AFUDC-Equity represents the cost of capital (i.e. ROE) that is added to the construction cost of an asset while it is being built. The tax benefit for regulated utilities from AFUDC-Equity is a regulatory gross-up to allow the recovery of income taxes on the equity portion of construction costs, even though it is not a tax deductible expense.

(4)    The Tax Legislation required our regulated utilities to remeasure their deferred income taxes and we began to amortize the resulting excess deferred income taxes beginning in 2018, in accordance with normalization requirements. The decrease in income tax expense related to the amortization of the deferred tax benefits is offset by a decrease in revenue as the benefits are returned to customers, resulting in no impact on net income.
Deferred Income Tax Assets and Liabilities

The components of deferred income taxes as of December 31 were as follows:
(in millions)20252024
Deferred tax assets
Tax gross up – regulatory items$416.9 $420.1 
Future tax benefits240.9 165.4 
Deferred revenues76.8 76.0 
Other206.1 167.9 
Total deferred tax assets940.7 829.4 
Valuation allowance(1.1)(1.1)
Net deferred tax assets$939.6 $828.3 
Deferred tax liabilities
Property-related$5,041.5 $4,545.2 
Investment in affiliates1,143.6 1,103.9 
Employee benefits and compensation229.2 231.4 
Deferred costs – plant retirements178.0 194.3 
Other239.0 268.2 
Total deferred tax liabilities6,831.3 6,343.0 
Deferred tax liability, net$5,891.7 $5,514.7 

Consistent with ratemaking treatment, deferred taxes related to our regulated utilities in the table above are offset for temporary differences that have related regulatory assets and liabilities.

The components of net deferred tax assets associated with federal and state tax benefit carryforwards as of December 31, 2025 and 2024 are summarized in the tables below:
2025 (in millions)
Gross ValueDeferred Tax EffectValuation AllowanceEarliest Year of Expiration
Future tax benefits as of December 31, 2025
Federal tax credit$ $206.5 $ 2042
State net operating loss685.6 34.1 (1.1)2032
Other state benefits 0.3  2029
Balance as of December 31, 2025
$685.6 $240.9 $(1.1)

2024 (in millions)
Gross ValueDeferred Tax EffectValuation AllowanceEarliest Year of Expiration
Future tax benefits as of December 31, 2024
Federal tax credit$— $157.9 $— 2042
State net operating loss107.5 7.2 (1.1)2032
Other state benefits— 0.3 — 2028
Balance as of December 31, 2024
$107.5 $165.4 $(1.1)

Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:
(in millions)202520242023
Balance as of January 1$4.4 $4.6 $6.3 
Additions for tax positions of prior years0.1 — 0.2 
Reductions for tax positions of prior years(1.5)(0.2)(1.9)
Balance as of December 31$3.0 $4.4 $4.6 
The amount of unrecognized tax benefits as of December 31, 2025 and 2024, excludes deferred tax assets related to uncertainty in income taxes of $0.7 million and $1.0 million, respectively. As of December 31, 2025 and 2024, the net amount of unrecognized tax benefits that, if recognized, would impact the effective tax rate for continuing operations was $2.3 million and $3.4 million, respectively.

Interest accrued related to unrecognized tax benefits is as follows:
(in millions)202520242023
Balance as of January 1$0.9 $0.6 $0.5 
Interest expense (income) related to unrecognized tax benefits(0.6)0.3 0.1 
Balance as of December 31$0.3 $0.9 $0.6 

For the years ended December 31, 2025, 2024, and 2023, we recognized no penalties related to unrecognized tax benefits in our consolidated income statements. At December 31, 2025 and 2024, we had no amounts accrued for penalties related to unrecognized tax benefits.

We file income tax returns in the United States federal jurisdiction and state tax returns based on income in our major state operating jurisdictions of Wisconsin, Illinois, Michigan, and Minnesota. We also file tax returns in other state and local jurisdictions with varying statutes of limitations. As of December 31, 2025, with a few exceptions, we were subject to examination by federal and state or local tax authorities for the 2021 through 2025 tax years in our major operating jurisdictions as follows:
JurisdictionYears
Federal
2022–2025
Illinois
2021–2025
Michigan
2021–2025
Minnesota
2021–2025
Wisconsin
2021–2025

Cash Received For Income Taxes, Net

The table below is a summary of income taxes paid (received) by jurisdiction for the years ended December 31:
(in millions)202520242023
Federal
$(256.3)
(1)
$(265.0)
(2)
$(75.0)
(3)
State
(25.0)0.8 16.1 
Total income taxes received, net
$(281.3)$(264.2)$(58.9)

(1)    Includes $256.3 million related to 2025 and 2024 PTCs that were sold to third parties.

(2)    Includes $269.1 million related to 2024 and 2023 PTCs that were sold to third parties.

(3)    Includes $75.0 million related to 2023 PTCs that were sold to third parties.

Income taxes received or paid (net of refunds) exceeded 5 percent of total income taxes received or paid (net of refunds) in the following jurisdiction:
(in millions)202520242023
Wisconsin
$(25.0)$— 
(1)
$12.0 

(1)    Jurisdiction below the threshold for the period presented.
v3.25.4
Fair Value Measurements
12 Months Ended
Dec. 31, 2025
Fair Value Disclosures [Abstract]  
FAIR VALUE MEASUREMENTS FAIR VALUE MEASUREMENTS
The following tables summarize our financial assets and liabilities that were accounted for at fair value on a recurring basis, categorized by level within the fair value hierarchy:
December 31, 2025
(in millions)Level 1Level 2Level 3Total
Derivative assets
Natural gas contracts$1.5 $18.3 $ $19.8 
FTRs and TCRs  6.5 6.5 
Total derivative assets$1.5 $18.3 $6.5 $26.3 
Investments held in rabbi trust $42.0 $ $ $42.0 
Derivative liabilities
Natural gas contracts$23.3 $8.4 $ $31.7 
FTRs and TCRs  0.8 0.8 
Total derivative liabilities$23.3 $8.4 $0.8 $32.5 

December 31, 2024
(in millions)Level 1Level 2Level 3Total
Derivative assets
Natural gas contracts$19.6 $13.7 $— $33.3 
FTRs and TCRs— — 7.8 7.8 
Total derivative assets$19.6 $13.7 $7.8 $41.1 
Investments held in rabbi trust $52.1 $— $— $52.1 
Derivative liabilities
Natural gas contracts$7.1 $6.8 $— $13.9 

The derivative assets and liabilities listed in the tables above include options, futures, physical commodity contracts, and other instruments used to manage market risks related to changes in commodity prices. They also include FTRs and TCRs, which are used at our electric utilities and certain of our non-utility wind parks to manage electric transmission congestion costs in the MISO Energy Markets and the Southwest Power Pool, Inc. Integrated Marketplace, respectively.

We hold investments in the Integrys rabbi trust. These investments are used to fund participants' benefits under the Integrys deferred compensation plan and certain Integrys non-qualified pension plans. These investments are included in other long-term assets on our balance sheets. During the years ended December 31, 2025, 2024, and 2023, the net unrealized gains included in earnings related to the investments held at the end of the period were $5.8 million, $9.0 million, and $10.0 million, respectively.

The following table summarizes the changes to derivatives classified as Level 3 in the fair value hierarchy at December 31:
(in millions)202520242023
Balance at the beginning of the period$7.8 $7.2 $7.8 
Purchases23.7 28.7 21.0 
Net realized and unrealized losses included in earnings (1)
 (0.7)(0.5)
Sales(1.0)— — 
Settlements(24.8)(27.4)(21.1)
Balance at the end of the period$5.7 $7.8 $7.2 
Net unrealized gains included in earnings attributable to Level 3 derivatives held at the end of the reporting period (1)
$0.1 $— $0.5 

(1)    Amounts relate to FTRs and TCRs included in our non-utility energy infrastructure segment. These net realized and unrealized gains and losses are recorded in operating revenues on our income statements.
Fair Value of Financial Instruments

The following table shows the financial instruments included on our balance sheets that are not recorded at fair value at December 31:
20252024
(in millions)Carrying AmountFair ValueCarrying AmountFair Value
Preferred stock of subsidiary$30.4 $21.2 $30.4 $21.2 
Long-term debt, including current portion20,017.5 19,609.1 18,907.1 17,840.8 

The fair values of our long-term debt and preferred stock are categorized within Level 2 of the fair value hierarchy.
v3.25.4
Derivative Instruments
12 Months Ended
Dec. 31, 2025
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
DERIVATIVE INSTRUMENTS DERIVATIVE INSTRUMENTS
Derivative assets and liabilities are included in the other current and other long-term line items on our balance sheets. The following table shows our derivative assets and derivative liabilities. None of the derivatives shown below were designated as hedging instruments.
December 31, 2025December 31, 2024
(in millions)Derivative
Assets
Derivative
Liabilities
Derivative
Assets
Derivative
Liabilities
Current
Natural gas contracts$19.7 $30.0 $29.2 $13.9 
FTRs and TCRs6.5 0.8 7.8 — 
Total current26.2 30.8 37.0 13.9 
Long-term
Natural gas contracts0.1 1.7 4.1 — 
Total$26.3 $32.5 $41.1 $13.9 

Realized gains and losses on derivatives used in our regulated utility operations are recorded in cost of sales upon settlement; however, they may be subsequently deferred for future rate recovery or refund as the gains and losses are included in our utilities’ fuel and natural gas cost recovery mechanisms. Realized gains and losses on FTRs and TCRs used in our non-utility operations are recorded in operating revenues on the income statements. Our realized gains and losses and the estimated notional volumes related to these settlements were as follows for the years ended:
December 31, 2025December 31, 2024December 31, 2023
(in millions)VolumesGains (Losses)VolumesGains (Losses)VolumesGains (Losses)
Natural gas contracts
202.4 Dth
$(19.2)
206.3 Dth
$(127.8)
198.0 Dth
$(259.1)
FTRs and TCRs
Regulated utility operations
26.3 MWh
18.9 
28.4 MWh
8.3 
29.3 MWh
27.4 
Non-utility operations
0.7 MWh
(0.1)
1.3 MWh
(0.1)
0.9 MWh
(1.5)
Total$(0.4)$(119.6)$(233.2)

At December 31, 2025 and 2024, we had posted cash collateral of $41.4 million and $16.0 million, respectively. We had also received cash collateral of $4.2 million at December 31, 2024.
The following table shows derivative assets and derivative liabilities if derivative instruments by counterparty were presented net on our balance sheets:
December 31, 2025December 31, 2024
(in millions)Derivative
Assets
Derivative
Liabilities
Derivative
Assets
Derivative
Liabilities
Gross amount recognized on the balance sheet$26.3 $32.5 $41.1 $13.9 
Gross amount not offset on the balance sheet (2.0)(23.8)
(1)
(11.5)
(2)
(7.3)
Net amount$24.3 $8.7 $29.6 $6.6 

(1)    Includes cash collateral posted of $21.8 million.

(2)    Includes cash collateral received of $4.2 million.

Cash Flow Hedges

We previously entered into forward interest rate swap agreements to mitigate the interest rate exposure associated with the issuance of long-term debt related to the acquisition of Integrys. These swap agreements were settled in 2015, and we continue to amortize amounts out of accumulated other comprehensive loss into interest expense over the periods in which the interest costs are recognized in earnings. The derivative gains related to these swap agreements reclassified from accumulated other comprehensive loss to interest expense during the years ended December 31, 2025, 2024, and 2023 were not significant. At December 31, 2025, the amount expected to be reclassified from accumulated other comprehensive loss to interest expense over the next twelve months was also not significant.
v3.25.4
Guarantees
12 Months Ended
Dec. 31, 2025
Guarantees [Abstract]  
GUARANTEES GUARANTEES
The following table shows our outstanding guarantees:
Total Amounts Committed at December 31, 2025Expiration
(in millions)
Less Than 1 Year1 to 3 YearsOver 3 Years
Standby letters of credit (1)
$188.2 $30.7 $30.2 $127.3 
Surety bonds (2)
46.5 46.4 0.1 — 
Other guarantees (3)
9.6 — — 9.6 
Total guarantees$244.3 $77.1 $30.3 $136.9 

(1)    At our request or the request of our subsidiaries, financial institutions have issued standby letters of credit for the benefit of third parties that have extended credit to our subsidiaries. These amounts are not reflected on our balance sheets.

(2)    Primarily for environmental remediation, workers compensation self-insurance programs, and obtaining various licenses, permits, and rights-of-way. These amounts are not reflected on our balance sheets.

(3)    Related to workers compensation coverage for which a liability was recorded on our balance sheets.
v3.25.4
Employee Benefits
12 Months Ended
Dec. 31, 2025
Retirement Benefits [Abstract]  
EMPLOYEE BENEFITS EMPLOYEE BENEFITS
Pension and Other Postretirement Employee Benefits

We and our subsidiaries have defined benefit pension plans that cover substantially all of our employees, as well as several unfunded non-qualified retirement plans. In addition, we and our subsidiaries offer multiple OPEB plans to employees. The benefits for a portion of these plans are funded through irrevocable trusts, as allowed for income tax purposes. We also offer medical, dental, and life insurance benefits to active employees and their dependents. We expense the costs of these benefits as incurred.

Generally, other than those employees who receive a contribution to their 401(k) savings plan as described below, former Wisconsin Energy Corporation employees receive a benefit based on a percentage of their annual salary plus an interest credit. Wisconsin Energy Corporation management employees hired after December 31, 2014, and certain new represented employees hired after May 1, 2017, receive an annual company contribution to their 401(k) savings plan instead of being enrolled in the defined benefit plans.
For former Integrys employees, the defined benefit pension plans are closed to all new hires. In addition, the service accruals for the defined benefit pension plans were frozen for non-union employees as of January 1, 2013. These employees receive an annual company contribution to their 401(k) savings plan, which is calculated based on age, wages, and full years of vesting service as of December 31 each year.

We use a year-end measurement date to measure the funded status of all of our pension and OPEB plans. Due to the regulated nature of our business, we have concluded that substantially all of the unrecognized costs resulting from the recognition of the funded status of our pension and OPEB plans qualify as a regulatory asset.

The following tables provide a reconciliation of the changes in our plans' benefit obligations and fair value of assets:
Pension BenefitsOPEB Benefits
(in millions)2025202420252024
Change in benefit obligation
Obligation at January 1$2,209.2 $2,352.4 $460.9 $448.1 
Service cost20.8 24.2 11.3 10.9 
Interest cost118.6 116.6 25.7 22.7 
Participant contributions — 11.5 11.2 
Plan amendments — (0.4)— 
Actuarial (gain) loss8.2 (99.6)28.3 6.9 
Benefit payments(193.7)(184.4)(46.8)(41.7)
Federal subsidy on benefits paidN/AN/A1.4 1.4 
Transfer — 1.5 1.4 
Obligation at December 31$2,163.1 $2,209.2 $493.4 $460.9 
Change in fair value of plan assets
Fair value at January 1$2,624.3 $2,665.8 $850.0 $829.6 
Actual return on plan assets221.6 129.8 87.9 49.5 
Employer contributions net of plan transfer
11.8 13.1 1.9 1.4 
Participant contributions — 11.5 11.2 
Benefit payments(193.7)(184.4)(46.8)(41.7)
Fair value at December 31$2,664.0 $2,624.3 $904.5 $850.0 
Funded status at December 31$500.9 $415.1 $411.1 $389.1 

In 2025, we had actuarial losses related to our pension benefit obligations of $8.2 million and actuarial gains in 2024 of $99.6 million. The primary driver for the actuarial loss was the decrease in discount rate. The primary driver for the actuarial gain was a higher discount rate in 2024. Partially offsetting the gain in 2024, was lower than expected asset returns. The discount rate for our pension benefits was 5.50%, 5.69%, and 5.19% in 2025, 2024, and 2023, respectively.

In 2025 and 2024, we had actuarial losses related to our OPEB benefit obligation of $28.3 million and $6.9 million, respectively, both of which were driven by changes to medical trend assumptions and claims and premium updates. The 2025 loss was also driven by a lower discount rate. Partially offsetting the loss in 2024, was a higher discount rate. The discount rate for our OPEB benefits was 5.54%, 5.71%, and 5.16% in 2025, 2024, and 2023, respectively.

The amounts recognized on our balance sheets at December 31 related to the funded status of the benefit plans were as follows:
Pension BenefitsOPEB Benefits
(in millions)2025202420252024
Pension and OPEB assets$646.3 $562.4 $436.1 $406.1 
Other long-term liabilities145.4 147.3 25.0 17.0 
Total net assets$500.9 $415.1 $411.1 $389.1 

The accumulated benefit obligation for all defined benefit pension plans was $2,112.5 million and $2,156.8 million as of December 31, 2025 and 2024, respectively.
The following table shows information for pension plans with an accumulated benefit obligation in excess of plan assets. Amounts presented are as of December 31:
(in millions)20252024
Accumulated benefit obligation$283.0 $286.0 
Fair value of plan assets141.7 143.2 

The following table shows information for pension plans with a projected benefit obligation in excess of plan assets. Amounts presented are as of December 31:
(in millions)20252024
Projected benefit obligation$287.1 $290.5 
Fair value of plan assets141.7 143.2 

The following table shows information for OPEB plans with an accumulated benefit obligation in excess of plan assets. Amounts presented are as of December 31:
(in millions)20252024
Accumulated benefit obligation$205.5 $194.0 
Fair value of plan assets180.5 177.0 

The following table shows the amounts that had not yet been recognized in our net periodic benefit cost (credit) as of December 31:
Pension BenefitsOPEB Benefits
(in millions)2025202420252024
Pre-tax accumulated other comprehensive income (loss) (1)
Net actuarial loss (gain)$11.6 $12.3 $(1.0)$(1.1)
Net regulatory assets (liabilities) (2)
Net actuarial loss (gain)$501.1 $578.7 $(146.1)$(148.8)
Prior service credits(2.0)(2.1)(8.4)(15.8)
Total$499.1 $576.6 $(154.5)$(164.6)

(1)    Amounts related to the nonregulated entities are included in accumulated other comprehensive loss.

(2)    Amounts related to the utilities and WBS are recorded as net regulatory assets or liabilities.

The components of net periodic benefit cost (credit) (including amounts capitalized to our balance sheets) for the years ended December 31 were as follows:
Pension BenefitsOPEB Benefits
(in millions)202520242023202520242023
Service cost$20.8 $24.2 $24.0 $11.3 $10.9 $9.8 
Interest cost118.6 116.6 122.3 25.7 22.7 21.6 
Expected return on plan assets(175.1)(182.1)(187.4)(54.3)(52.7)(53.0)
Plan settlement(1.2)4.0 1.3  — — 
Amortization of prior service cost (credit)(0.1)(0.1)— (7.8)(13.5)(14.8)
Amortization of net actuarial loss (gain)41.1 59.5 33.0 (8.2)(7.6)(12.3)
Net periodic benefit cost (credit)$4.1 $22.1 $(6.8)$(33.3)$(40.2)$(48.7)

Effective January 1, 2023, the PSCW approved escrow accounting for pension and OPEB costs. As a result, as of December 31, 2025 and 2024, our balance sheet included a $14.7 million regulatory liability and a $24.9 million regulatory asset for pension costs, respectively, and a $0.7 million and a $38.2 million regulatory asset for OPEB costs, respectively.
The weighted-average assumptions used to determine the benefit obligations for the plans were as follows for the years ended December 31:
Pension BenefitsOPEB Benefits
2025202420252024
Discount rate5.50%5.69%5.54%5.71%
Rate of compensation increase4.00%4.00%N/AN/A
Interest credit rate4.83%4.85%N/AN/A
Assumed medical cost trend rate (Pre 65)N/AN/A8.00%7.00%
Ultimate trend rate (Pre 65)N/AN/A5.00%5.00%
Year ultimate trend rate is reached (Pre 65)N/AN/A20322033
Assumed medical cost trend rate (Post 65)N/AN/A9.92%6.10%
Ultimate trend rate (Post 65)N/AN/A5.00%5.00%
Year ultimate trend rate is reached (Post 65)N/AN/A20342030

The weighted-average assumptions used to determine the net periodic benefit cost for the plans were as follows for the years ended December 31:
Pension Benefits
202520242023
Discount rate5.69%5.18%5.49%
Expected return on plan assets6.61%6.61%6.62%
Rate of compensation increase4.00%4.00%4.00%
Interest credit rate4.85%4.84%4.62%

OPEB Benefits
202520242023
Discount rate5.71%5.16%5.50%
Expected return on plan assets6.50%6.50%6.50%
Assumed medical cost trend rate (Pre 65)7.00%6.25%6.50%
Ultimate trend rate (Pre 65)5.00%5.00%5.00%
Year ultimate trend rate is reached (Pre 65)203320312031
Assumed medical cost trend rate (Post 65)6.10%6.39%6.00%
Ultimate trend rate (Post 65)5.00%5.00%5.00%
Year ultimate trend rate is reached (Post 65)203020302031

We consult with our investment advisors on an annual basis to help us forecast expected long-term returns on plan assets by reviewing historical returns as well as calculating expected total trust returns using the weighted-average of long-term market returns for each of the major target asset categories utilized in the trust. For 2026, the expected return on assets assumption is 6.61% for the pension plans and 6.50% for the OPEB plans.

Plan Assets

Current pension trust assets and amounts which are expected to be contributed to the trusts in the future are expected to be adequate to meet pension payment obligations to current and future retirees.

The Investment Trust Policy Committee oversees investment matters related to all of our funded benefit plans. The Committee works with external actuaries and investment consultants on an on-going basis to establish and monitor investment strategies and target asset allocations. Forecasted cash flows for plan liabilities are regularly updated based on annual valuation results. Target allocations are determined utilizing projected benefit payment cash flows and risk analyses of appropriate investments. They are intended to reduce risk, provide long-term financial stability for the plans and maintain funded levels which meet long-term plan obligations while preserving sufficient liquidity for near-term benefit payments.

The target asset allocations are 25% equity investments, 55% fixed income investments, and 20% private equity and real estate investments for both the legacy Wisconsin Energy Corporation and legacy Integrys pension trusts. The legacy Wisconsin Energy Corporation OPEB trust target asset allocations are 45% equity investments, 45% fixed income investments, and 10% real estate
investments. The two largest legacy OPEB trusts for Integrys have the same target asset allocations of 45% equity investments, 45% fixed income investments, and 10% real estate investments. Equity securities include investments in large-cap, mid-cap, and small-cap companies. Fixed income securities include corporate bonds of companies from diversified industries, mortgage and other asset backed securities, commercial paper, and United States Treasuries.

Pension and OPEB plan investments are recorded at fair value. See Note 1(r), Fair Value Measurements, for more information regarding the fair value hierarchy and the classification of fair value measurements based on the types of inputs used.

The following tables provide the fair values of our investments by asset class:
December 31, 2025
Pension Plan AssetsOPEB Assets
(in millions)Level 1Level 2Level 3TotalLevel 1Level 2Level 3Total
Asset Class
Equity securities:
United States equity$160.8 $ $ $160.8 $97.3 $ $ $97.3 
International equity173.7   173.7 100.8   100.8 
Fixed income securities: (1)
United States bonds 933.5 1.4 934.9 110.6 219.3 0.1 330.0 
International bonds 63.5  63.5  7.7  7.7 
$334.5 $997.0 $1.4 $1,332.9 $308.7 $227.0 $0.1 $535.8 
Investments measured at net asset value:
Equity securities412.6 206.0 
Fixed income securities127.6 55.3 
Other790.9 107.4 
Total$2,664.0 $904.5 

(1)    This category represents investment grade bonds of United States and foreign issuers denominated in United States dollars from diverse industries.
December 31, 2024
Pension Plan AssetsOPEB Assets
(in millions)Level 1Level 2Level 3TotalLevel 1Level 2Level 3Total
Asset Class
Equity securities:
United States equity$168.4 $— $— $168.4 $93.8 $— $— $93.8 
International equity158.2 — — 158.2 86.4 — — 86.4 
Fixed income securities: (1)
United States bonds— 880.1 — 880.1 99.0 205.6 — 304.6 
International bonds— 81.6 — 81.6 — 11.2 — 11.2 
$326.6 $961.7 $— $1,288.3 $279.2 $216.8 $— $496.0 
Investments measured at net asset value:
Equity securities414.9 190.4 
Fixed income securities126.0 51.8 
Other795.1 111.8 
Total$2,624.3 $850.0 

(1)    This category represents investment grade bonds of United States and foreign issuers denominated in United States dollars from diverse industries.
The following tables set forth a reconciliation of changes in fair values of pension and OPEB plan assets categorized as Level 3 in the fair value hierarchy:
United States Bonds
(in millions)PensionOPEB
Beginning balance at January 1, 2025
$ $ 
Purchases1.4 0.1 
Ending balance at December 31, 2025$1.4 $0.1 

Cash Flows

We expect to contribute $16.5 million to the pension plans and $2.8 million to the OPEB plans in 2026, dependent upon various factors affecting us, including our liquidity position and possible tax law changes.

The following table shows the payments, reflecting expected future service, that we expect to make for pension and OPEB over the next 10 years:
(in millions)Pension BenefitsOPEB Benefits
2026$213.5 $35.5 
2027203.1 37.6 
2028193.5 38.7 
2029187.5 39.5 
2030182.1 39.8 
2031-2035801.3 197.8 

Savings Plans

We sponsor 401(k) savings plans which allow employees to contribute a portion of their pre-tax and/or after-tax income in accordance with plan-specified guidelines. A percentage of employee contributions are matched by us through a contribution into the employee's savings plan account, up to certain limits. The 401(k) savings plans include an Employee Stock Ownership Plan. Certain employees receive a retirement contribution in lieu of receiving a pension benefit. Total costs incurred under all of these plans were $67.3 million, $61.6 million, and $57.5 million in 2025, 2024, and 2023, respectively.
v3.25.4
Investment in Transmission Affiliates
12 Months Ended
Dec. 31, 2025
Equity Method Investments and Joint Ventures [Abstract]  
INVESTMENT IN TRANSMISSION AFFILATES INVESTMENT IN TRANSMISSION AFFILIATES
We own approximately 60% of ATC, a for-profit, transmission-only company regulated by the FERC for cost of service and certain state regulatory commissions for routing and siting of transmission projects. We also own approximately 75% of ATC Holdco, a separate entity formed in December 2016 to invest in transmission-related projects outside of ATC's traditional footprint. ATC's corporate manager has an 11-member board of directors, and ATC Holdco's corporate manager has a four-member board of directors. We have one representative on each board. Each member of the board has only one vote. The following tables provide a reconciliation of the changes in our investments in ATC and ATC Holdco:
2025
(in millions)ATCATC HoldcoTotal
Balance at January 1$2,085.1 $23.8 $2,108.9 
Add: Earnings from equity method investment209.7 6.1 215.8 
Add: Capital contributions142.4  142.4 
Less: Distributions180.2 6.4 186.6 
Less: Other0.1  0.1 
Balance at December 31$2,256.9 $23.5 $2,280.4 
2024
(in millions)ATCATC HoldcoTotal
Balance at January 1$1,980.8 $25.1 $2,005.9 
Add: Earnings from equity method investment205.4 2.1 207.5 
Add: Capital contributions45.5 — 45.5 
Less: Distributions146.7 3.4 150.1 
Add: Other0.1 — 0.1 
Balance at December 31$2,085.1 $23.8 $2,108.9 

2023
(in millions)ATCATC HoldcoTotal
Balance at January 1$1,884.6 $24.6 $1,909.2 
Add: Earnings from equity method investment175.1 2.4 177.5 
Add: Capital contributions63.7 — 63.7 
Less: Distributions142.6 1.9 144.5 
Balance at December 31$1,980.8 $25.1 $2,005.9 

The ROE allowed by the FERC helps determine how much transmission owners, such as ATC, earn on their transmission assets as well as how much consumers pay for those assets. In November 2013, a complaint was filed arguing the base ROE for MISO transmission owners was too high. The D.C. Circuit Court of Appeals issued an opinion in August 2022 for this ROE complaint that resulted in ATC recording a reserve for potential refunds based on a 9.88% base ROE. In response to this opinion, the FERC issued an order in October 2024 that required ATC to adopt a 9.98% base ROE. Due to the change between the 9.88% base ROE originally reflected in ATC's reserve and the 9.98% base ROE authorized in the October 2024 FERC order, ATC reduced its refund liability, which increased our pre-tax equity earnings by $20.1 million during 2024.

We pay ATC for network transmission and other related services it provides. In addition, we provide a variety of operational, maintenance, and project management work for ATC, which is reimbursed by ATC. We are also required to initially fund the construction of transmission infrastructure upgrades needed for new generation projects. ATC owns these transmission assets and reimburses us for these costs when the new generation is placed in service.

The following table summarizes our significant related party transactions with ATC during the years ended December 31:
(in millions)202520242023
Charges to ATC for services and construction$20.2 $21.6 $17.4 
Charges from ATC for network transmission services466.9 413.3 377.5 
Refund from ATC related to FERC ROE orders
5.2 — — 

As of December 31, 2025 and 2024, our balance sheets included the following receivables and payables for services provided to or received from ATC:
(in millions)20252024
Accounts receivable for services provided to ATC$1.6 $1.4 
Accounts payable for services received from ATC38.4 34.4 
Amounts due from ATC for transmission infrastructure upgrades (1)
32.2 54.5 

(1)    The transmission infrastructure upgrades were primarily related to the construction of WE's, WPS's, and UMERC's renewable energy projects.
Summarized financial data for ATC is included in the tables below:
Year Ended December 31
(in millions)202520242023
Income statement data
Operating revenues$975.0 $911.3 $818.9 
Operating expenses472.6 442.4 407.6 
Other expense, net165.8 137.7 131.7 
Net income$336.6 $331.2 $279.6 

(in millions)December 31, 2025December 31, 2024
Balance sheet data
Current assets$137.5 $126.6 
Noncurrent assets7,590.8 6,792.6 
Total assets$7,728.3 $6,919.2 
Current liabilities$839.8 $482.4 
Long-term debt3,156.3 3,083.4 
Other noncurrent liabilities638.9 545.0 
Members' equity3,093.3 2,808.4 
Total liabilities and members' equity$7,728.3 $6,919.2 
v3.25.4
Segment Information
12 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
SEGMENT INFORMATION SEGMENT INFORMATION
Our President and CEO, who is our CODM, reviews financial information presented on a segment basis for purposes of making operating decisions and assessing performance. The CODM regularly reviews net income attributed to common shareholders to measure segment profitability and to allocate resources, including assets, to our businesses. Net income attributed to common shareholders best measures our segment profitability as it reflects all revenues and costs, including the impact on our tax provision from tax credits generated through investments in renewable generation facilities.

Our CODM allocates resources, such as employees, as well as financial and capital resources, to our segments during the annual review of budgets and the capital plan. Our CODM also reviews and revises the resources throughout the year during the monthly forecasting process in order to make timely decisions that align with our overall corporate strategy. The CODM uses each segment’s net income to evaluate performance by comparing actual results to budgeted and forecasted amounts, as well as the ROE earned for each utility within the various utility segments.

Segments were determined based on a combination of factors, including the regulatory environment of each geographical jurisdiction in which the segment operates, equity investment interests, as well as the revenue streams for the products or services provided to customers through electric, natural gas, and renewable operations. See Note 4, Operating Revenues, for more information on disaggregation of operating revenues, including intercompany eliminations. The accounting policies of the segments are the same as those described in Note 1, Summary of Significant Accounting Policies.

At December 31, 2025, we reported six segments, which are described below. All of our operations are located within the United States.

The Wisconsin segment includes the electric and natural gas utility operations of WE, WPS, WG, and UMERC.

The Illinois segment includes the natural gas utility operations of PGL and NSG.

The other states segment includes the natural gas utility operations of MERC and MGU and the non-utility operations of MERC.
The electric transmission segment includes our approximate 60% ownership interest in ATC, a for-profit, transmission-only company regulated by the FERC for cost of service and certain state regulatory commissions for routing and siting of transmission projects, and our approximate 75% ownership interest in ATC Holdco, which was formed to invest in transmission-related projects outside of ATC's traditional footprint. See Note 21, Investment in Transmission Affiliates, for more information on ATC and ATC Holdco.

The non-utility energy infrastructure segment includes:
We Power, which owns and leases generating facilities to WE,
Bluewater, which owns underground natural gas storage facilities in Michigan that provide approximately one-third of the current storage needs for our Wisconsin natural gas utilities, and
WECI, which owns majority interests in multiple renewable generating facilities.

See Note 2, Acquisitions, for more information on recent WECI acquisitions.

The corporate and other segment includes the operations of the WEC Energy Group holding company, the Integrys holding company, the PELLC holding company, Wispark, Wisvest, WECC, and WBS.
The following tables show summarized financial information related to our reportable segments for the years ended December 31, 2025, 2024, and 2023.
 Utility Operations  
2025 (in millions)
WisconsinIllinoisOther States
Total Utility Operations
Electric TransmissionNon-Utility Energy Infrastructure
Corporate and Other
Reconciling Eliminations
WEC Energy Group Consolidated
External revenues $7,295.5 $1,683.6 $527.5 $9,506.6 $ $293.5 $ $ $9,800.1 
Intersegment revenues     476.7  (476.7) 
Fuel and purchased power
1,674.9   1,674.9     1,674.9 
Cost of natural gas sold
871.5 508.0 246.3 1,625.8  9.6  (44.5)1,590.9 
Other operation and maintenance1,737.9 482.2 104.6 2,324.7  95.5 (10.2)(9.2)2,400.8 
Impairments related to Illinois segment 130.0  130.0     130.0 
Depreciation and amortization1,008.1 259.7 49.8 1,317.6  240.2 21.6 (100.9)1,478.5 
Property and revenue taxes
178.7 55.5 26.2 260.4  19.6 0.1  280.1 
Equity in earnings of transmission affiliates    215.8    215.8 
Other income, net (1)
96.5 8.6 0.4 105.5  2.8 30.6 (31.0)107.9 
Interest expense638.7 88.9 19.2 746.8 19.3 123.1 359.0 (353.1)895.1 
Income tax expense (benefit)226.2 45.8 21.0 293.0 48.9 (122.9)(101.0) 118.0 
Preferred stock dividends of subsidiary
1.2   1.2     1.2 
Net loss attributed to noncontrolling interests
     3.2   3.2 
Net income (loss) attributed to common shareholders$1,054.8 $122.1 $60.8 $1,237.7 $147.6 $411.1 $(238.9)$ $1,557.5 
Other Segment Disclosures
Capital expenditures and asset acquisitions$3,860.1 $306.1 $112.5 $4,278.7 $ $504.7 $20.8 $ $4,804.2 
Equity method investments
17.8   17.8 2,280.4  55.7  2,353.9 
Total assets (2)
33,984.7 8,167.7 1,733.3 43,885.7 2,282.8 7,762.9 1,227.6 (3,640.7)51,518.3 

(1)Includes amounts that are not material for interest income and other equity earnings from investments other than from transmission affiliates.

(2)    Total assets at December 31, 2025 reflect an elimination of $2,594.8 million for all lease activity between We Power and WE.
Utility Operations  
2024 (in millions)
WisconsinIllinoisOther States
Total Utility Operations
Electric TransmissionNon-Utility Energy Infrastructure
Corporate and Other
Reconciling Eliminations
WEC Energy Group Consolidated
External revenues $6,330.5 $1,602.4 $449.8 $8,382.7 $— $217.2 $— $— $8,599.9 
Intersegment revenues— — — — — 474.1 — (474.1)— 
Fuel and purchased power
1,455.7 — — 1,455.7 — — — — 1,455.7 
Cost of natural gas sold
661.9 376.7 198.6 1,237.2 — 9.1 — (46.0)1,200.3 
Other operation and maintenance1,547.9 461.5 93.9 2,103.3 — 75.1 (11.3)(9.1)2,158.0 
Impairments related to Illinois segment— 12.1 — 12.1 — — — — 12.1 
Depreciation and amortization919.9 255.4 47.0 1,222.3 — 198.4 22.3 (88.5)1,354.5 
Property and revenue taxes
169.6 59.9 21.0 250.5 — 15.7 0.3 — 266.5 
Equity in earnings of transmission affiliates— — — — 207.5 — — — 207.5 
Other income, net (1)
146.6 7.6 0.3 154.5 — 1.0 54.4 (31.7)178.2 
Interest expense637.3 94.7 16.4 748.4 19.4 99.7 310.0 (362.2)815.3 
Gain on debt extinguishments
— — — — — — (23.1)— (23.1)
Income tax expense (benefit)220.5 97.6 18.7 336.8 47.1 (82.4)(79.5)— 222.0 
Preferred stock dividends of subsidiary
1.2 — — 1.2 — — — — 1.2 
Net loss attributed to noncontrolling interests
— — — — — 4.1 — — 4.1 
Net income (loss) attributed to common shareholders$863.1 $252.1 $54.5 $1,169.7 $141.0 $380.8 $(164.3)$— $1,527.2 
Other Segment Disclosures
Capital expenditures and asset acquisitions$2,347.1 $343.0 $118.3 $2,808.4 $— $945.8 $20.6 $— $3,774.8 
Equity method investments
15.7 — — 15.7 2,108.9 — 67.0 — 2,191.6 
Total assets (2)
30,622.7 8,168.8 1,646.0 40,437.5 2,126.0 7,316.0 1,037.3 (3,553.6)47,363.2 

(1)Includes amounts that are not material for interest income and other equity earnings from investments other than from transmission affiliates.

(2)    Total assets at December 31, 2024 reflect an elimination of $1,525.4 million for all lease activity between We Power and WE.
 Utility Operations  
2023 (in millions)
WisconsinIllinoisOther States
Total Utility Operations
Electric TransmissionNon-Utility Energy Infrastructure
Corporate and Other
Reconciling Eliminations
WEC Energy Group Consolidated
External revenues $6,625.9 $1,557.8 $519.1 $8,702.8 $— $190.1 $0.1 $— $8,893.0 
Intersegment revenues— — — — — 476.4 — (476.4)— 
Fuel and purchased power
1,615.9 — — 1,615.9 — — — — 1,615.9 
Cost of natural gas sold
894.7 443.0 277.2 1,614.9 — 20.5 — (60.1)1,575.3 
Other operation and maintenance1,531.3 397.9 94.5 2,023.7 — 80.1 5.8 (9.1)2,100.5 
Impairments related to Illinois segment— 178.9 — 178.9 — — — — 178.9 
Depreciation and amortization851.5 237.3 43.3 1,132.1 — 188.7 20.9 (77.5)1,264.2 
Property and revenue taxes
179.2 29.9 24.4 233.5 — 16.5 0.2 — 250.2 
Equity in earnings of transmission affiliates— — — — 177.5 — — — 177.5 
Other income, net (1)
137.6 6.7 0.6 144.9 — — 53.3 (20.5)177.7 
Interest expense601.0 88.9 15.9 705.8 19.4 94.3 258.1 (350.2)727.4 
Gain on debt extinguishments— — — — — — (0.5)— (0.5)
Income tax expense (benefit)237.4 48.6 16.3 302.3 39.0 (68.4)(68.3)— 204.6 
Preferred stock dividends of subsidiary1.2 — — 1.2 — — — — 1.2 
Net loss attributed to noncontrolling interests— — — — — 1.2 — — 1.2 
Net income (loss) attributed to common shareholders$851.3 $140.0 $48.1 $1,039.4 $119.1 $336.0 $(162.8)$— $1,331.7 
Other Segment Disclosures
Capital expenditures and asset acquisitions$2,134.4 $489.8 $103.5 $2,727.7 $— $754.4 $25.8 $— $3,507.9 
Equity method investments
14.4 — — 14.4 2,005.9 — 61.3 — 2,081.6 
Total assets (2)
28,527.3 7,970.2 1,571.5 38,069.0 2,006.0 6,404.7 1,100.1 (3,640.1)43,939.7 

(1)    Includes amounts that are not material for interest income and other equity earnings from investments other than from transmission affiliates.

(2)    Total assets at December 31, 2023 reflect an elimination of $1,630.6 million for all lease activity between We Power and WE.
v3.25.4
Variable Interest Entities
12 Months Ended
Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
VARIABLE INTEREST ENTITIES VARIABLE INTEREST ENTITIES
The primary beneficiary of a VIE must consolidate the entity's assets and liabilities. In addition, certain disclosures are required for significant interest holders in VIEs.

We assess our relationships with potential VIEs, such as our coal suppliers, natural gas suppliers, coal transporters, natural gas transporters, and other counterparties related to PPAs, investments, and joint ventures. In making this assessment, we consider, along with other factors, the potential that our contracts or other arrangements provide subordinated financial support, the
obligation to absorb the entity's losses, the right to receive residual returns of the entity, and the power to direct the activities that most significantly impact the entity's economic performance.

WEPCo Environmental Trust Finance I, LLC

In November 2020, the PSCW issued a financing order approving the securitization of $100 million of undepreciated environmental control costs related to WE's retired Pleasant Prairie power plant, the carrying costs accrued on the $100 million during the securitization process, and the related financing fees. The financing order also authorized WE to form WEPCo Environmental Trust, a bankruptcy-remote special purpose entity, for the sole purpose of issuing ETBs to recover the costs approved in the financing order. WEPCo Environmental Trust is a wholly owned subsidiary of WE.

In May 2021, WEPCo Environmental Trust issued ETBs and used the proceeds to acquire environmental control property from WE. The environmental control property is recorded as a regulatory asset on our balance sheets and includes the right to impose, collect, and receive a non-bypassable environmental control charge from WE's retail electric distribution customers until the ETBs are paid in full and all financing costs have been recovered. The ETBs are secured by the environmental control property. Cash collections from the environmental control charge and funds on deposit in trust accounts are the sole sources of funds to satisfy the debt obligation. The bondholders do not have any recourse to WE or any of WE's affiliates.

WE acts as the servicer of the environmental control property on behalf of WEPCo Environmental Trust and is responsible for metering, calculating, billing, and collecting the environmental control charge. As necessary, WE is authorized to implement periodic adjustments of the environmental control charge. The adjustments are designed to ensure the timely payment of principal, interest, and other ongoing financing costs. WE remits all collections of the environmental control charge to WEPCo Environmental Trust's indenture trustee.

WEPCo Environmental Trust is a VIE primarily because its equity capitalization is insufficient to support its operations. As described above, WE has the power to direct the activities that most significantly impact WEPCo Environmental Trust's economic performance. Therefore, WE is considered the primary beneficiary of WEPCo Environmental Trust, and consolidation is required.

The following table summarizes the impact of WEPCo Environmental Trust on our balance sheets:
(in millions)December 31, 2025December 31, 2024
Assets
Other current assets (restricted cash)$2.0 $1.5 
Regulatory assets67.5 76.5 
Other long-term assets (restricted cash)0.6 0.6 
Liabilities
Current portion of long-term debt9.3 9.2 
Accounts payable0.1 — 
Other current liabilities (accrued interest)0.1 0.1 
Long-term debt67.4 76.4 

Investment in Transmission Affiliates

We own approximately 60% of ATC, a for-profit, electric transmission company regulated by the FERC and certain state regulatory commissions. We have determined that ATC is a VIE but consolidation is not required since we are not ATC's primary beneficiary. As a result of our limited voting rights, we do not have the power to direct the activities that most significantly impact ATC's economic performance. Therefore, we account for ATC as an equity method investment. At December 31, 2025 and 2024, our equity investment in ATC was $2,256.9 million and $2,085.1 million, respectively, which approximates our maximum exposure to loss as a result of our involvement with ATC.

We also own approximately 75% of ATC Holdco, a separate entity formed in December 2016 to invest in transmission-related projects outside of ATC's traditional footprint. We have determined that ATC Holdco is a VIE but consolidation is not required since we are not ATC Holdco's primary beneficiary. As a result of our limited voting rights, we do not have the power to direct the activities that most significantly impact ATC Holdco's economic performance. Therefore, we account for ATC Holdco as an equity
method investment. At December 31, 2025 and 2024, our equity investment in ATC Holdco was $23.5 million and $23.8 million, respectively, which approximates our maximum exposure to loss as a result of our involvement with ATC Holdco.

See Note 21, Investment in Transmission Affiliates, for more information, including any significant assets and liabilities related to ATC and ATC Holdco recorded on our balance sheets.
v3.25.4
Commitments and Contingencies
12 Months Ended
Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]  
COMMITMENTS AND CONTINGENCIES COMMITMENTS AND CONTINGENCIES
We and our subsidiaries have significant commitments and contingencies arising from our operations, including those related to unconditional purchase obligations, environmental matters, and enforcement and litigation matters.

Unconditional Purchase Obligations

Our electric utilities have obligations to distribute and sell electricity to their customers, and our natural gas utilities have obligations to distribute and sell natural gas to their customers. The utilities expect to recover costs related to these obligations in future customer rates. In order to meet these obligations, we routinely enter into long-term purchase and sale commitments for various quantities and lengths of time.

The renewable generation facilities that are part of our non-utility energy infrastructure segment have obligations to distribute and sell electricity through long-term offtake agreements with their customers for all of the energy produced. In order to support these sales obligations, these companies enter into easements and other service agreements associated with the generating facilities.

The following table shows our minimum future commitments related to these purchase obligations as of December 31, 2025, including those of our subsidiaries:
Payments Due By Period
(in millions)Date Contracts Extend ThroughTotal Amounts Committed20262027202820292030Later Years
Electric utility:
Nuclear2033$5,045.8 $681.6 $730.4 $782.6 $838.5 $898.5 $1,114.2 
Coal supply and transportation2028412.1 242.2 127.7 37.0 3.5 1.7 — 
Purchased power2063335.3 61.6 56.3 52.4 25.6 5.9 133.5 
Other204385.5 12.0 12.1 9.6 8.4 8.5 34.9 
Natural gas utility:
Supply and transportation20482,921.3 487.0 478.8 426.8 323.6 203.0 1,002.1 
Non-utility energy infrastructure:
Purchased power2055720.7 55.0 56.3 57.6 50.7 48.4 452.7 
Natural gas storage and transportation20484.6 3.9 — 0.1 — — 0.6 
Total$9,525.3 $1,543.3 $1,461.6 $1,366.1 $1,250.3 $1,166.0 $2,738.0 

Environmental Matters

Consistent with other companies in the energy industry, we face significant ongoing environmental compliance and remediation obligations related to current and past operations. Specific environmental issues affecting us include, but are not limited to, current and future regulation of air emissions such as SO2, NOx, fine particulates, ozone, mercury, and GHGs; water intake and discharges; management of coal combustion products such as fly ash; and remediation of impacted properties, including former manufactured gas plant sites.

We have continued to pursue a proactive strategy to manage our environmental compliance obligations, including:

the development of additional sources of renewable electric energy supply, battery storage, and natural gas and LNG storage facilities;
the addition of improvements for water quality matters such as treatment technologies to meet regulatory discharge limits and improvements to our cooling water intake systems;
the addition of emission control equipment to existing facilities to comply with ambient air quality standards and federal clean air rules;
the protection of wetlands and waterways, biodiversity including threatened and endangered species, and cultural resources associated with construction projects;
the retirement of older coal-fired power plants and conversion to modern, efficient, natural gas generation, super-critical pulverized coal generation, and/or replacement with renewable generation;
the beneficial use of ash and other products from coal-fired and biomass generating units;
the remediation of former manufactured gas plant sites;
the reduction of methane emissions across our natural gas distribution system by upgrading infrastructure; and
the tracking and reporting of GHG emissions.

Federal Deregulatory Actions

In March 2025, the EPA announced a large-scale deregulatory effort that will likely take multiple years to complete. Of the proposed deregulatory actions, those that would apply to us include actions impacting the Good Neighbor Rule, MATS, the PM2.5 Standard, the GHG Power Plant Rule, the Mandatory Greenhouse Gas Reporting Rule, the ELG, and the CCR Rule. Any EPA actions will require formal rulemaking proceedings and are likely to be subject to legal challenges. We continue to monitor and evaluate these deregulatory actions for potential risks and benefits.

In February 2026, the EPA published a final rule rescinding the 2009 declaration that determined that CO2 and other GHGs endanger public health and welfare. The "endangerment finding" has been the legal underpinning of a host of climate regulations under the CAA. The rule is expected to face litigation.

Air Quality

Cross State Air Pollution Rule – Good Neighbor Rule

In 2023, the EPA issued a final Good Neighbor Rule, which required significant reductions in ozone-forming emissions of NOx from power plants and industrial facilities. In June 2024, the rule was stayed by the Supreme Court with respect to the specific applicant states, pending ongoing judicial review.

In response to the Supreme Court's order, in November 2024, the EPA administratively stayed the effectiveness of the Good Neighbor Rule through an interim final rule which extends a stay to all states to which the rule originally applied, including states in which we operate. The interim final rule also includes provisions to ensure that covered facilities in states with previously established requirements to mitigate interstate air pollution with respect to the 2008 ozone NAAQS will remain subject to equivalent requirements while the Good Neighbor Rule's effectiveness is stayed. Regardless of the outcome, we believe we are well positioned to comply with either standard. See the Federal Deregulatory Actions discussion above for more information regarding potential deregulatory actions regarding this rule.

Mercury and Air Toxics Standards

The EPA issued the MATS rule to limit emissions of mercury, acid gases, and other hazardous air pollutants. In May 2024, the EPA finalized amendments to the MATS rule (the "2024 Amendments") which among other things, lowered the PM limit from 0.03 lb/MMBtu to 0.01 lb/MMBtu. We believe we are well positioned to comply with the requirements of the 2024 Amendments.

In June 2025, the EPA proposed to repeal the 2024 Amendments which would result in a return of the PM limit to 0.03 lb/MMBtu. In December 2025, the EPA submitted a draft of the rule to the OMB for interagency review. Following completion of the OMB review process, the EPA has stated it expects the rule to be finalized in the first quarter of 2026.

National Ambient Air Quality Standards

Ozone

After completing its review of the 2008 ozone standard, the EPA released a final rule in October 2015, creating a more stringent standard than the 2008 NAAQS. The 2015 ozone standard lowered the 8-hour limit for ground-level ozone. The EPA's initial ozone nonattainment area designation was effective August 2018, and the attainment status is evaluated every 3 years thereafter until attainment is achieved. The Milwaukee, Sheboygan, and Chicago, IL-IN-WI nonattainment areas did not meet the marginal attainment deadline of August 2021, so in April 2022 the EPA proposed "moderate" nonattainment status based on the 2015
standard. In October 2022, the EPA published its final reclassifications from "marginal" to "moderate" for these areas, effective November 2022.

After the most recent evaluation, the EPA issued a final rule in December 2024 that determined that parts of Southeast Wisconsin failed to attain 2015 ozone NAAQS and consequently would be reclassified from "moderate" to "serious", effective January 2025.

In February 2025, the State of Wisconsin filed a petition for review of this reclassification in the United States Court of Appeals for the Seventh Circuit. Wisconsin subsequently moved for a stay of the reclassification, which was granted in September 2025, pending the Court's review. This means that Southeast Wisconsin has returned to "moderate" status while the underlying lawsuit proceeds.

A nonattainment status of "serious" could have a material adverse effect on future permitting activities for our facilities in applicable locations, including additional costs associated with more strenuous emission control requirements or the need to purchase emission reduction credits.

Particulate Matter

All counties within our service territories are currently in attainment with current 2012 NAAQS for PM2.5. In February 2024, the EPA finalized a rule which lowered the primary (health-based) annual PM2.5 NAAQS from 12 µg/m3 to 9 µg/m3 (the "2024 PM2.5 Standard"). In February 2025, the WDNR submitted a State Implementation Plan to the EPA recommending Wisconsin be designated as an attainment area under the 2024 PM2.5 Standard. The EPA has not yet issued its attainment designations and has indicated it may extend the designation period. A designation of nonattainment status could impact future permitting activities for facilities in applicable locations, including the potential need for improved or new air pollution control equipment. With our planned transition from coal-fired plants to natural gas-fired plants and renewable generating facilities, we do not expect the 2024 PM2.5 Standard to have a material impact on our units.

In November 2025, the EPA filed a motion with the D.C. Circuit Court of Appeals to vacate the 2024 PM2.5 Standard. The 2024 PM2.5 Standard remains in effect while the motion is being considered. See the Federal Deregulatory Actions discussion above for more information regarding potential deregulatory actions regarding this rule.

New Source Performance Standards

Nitrogen Oxides

In January 2026, the EPA released a pre-publication version of its final rule regulating NOx for CTs constructed, modified, or reconstructed after December 13, 2024. The final rule, which became effective January 15, 2026 and established NOx emissions standards for several subcategories of new, modified, and reconstructed CTs based on the size, rates of utilization, design efficiency, and fuel type of these turbines. We believe we are well positioned to comply with this rule.

Climate Change

Pursuant to the final GHG Power Plant Rule, there are no applicable GHG emission standards for coal plants until the end of 2031. Thereafter, the applicable standard is dependent upon the unit's retirement date. Numerous parties have challenged the GHG Power Plant Rule through litigation pending in the D.C. Circuit Court of Appeals, and it is being held in abeyance at the request of the parties.

In March 2024, the EPA announced it had removed regulations on existing natural gas CTs from the rule. At that time, the EPA indicated it would work on new rulemaking in phases, focusing on CO2 emissions, as well as NOx and hazardous air pollutants emissions. See New Source Performance Standards - Nitrogen Oxides above for a discussion of the EPA's recent actions addressing NOx.

In June 2025, the EPA issued a proposed rule that contains a primary and an alternative proposal which, depending on which version is finalized, would result in either a broad repeal of GHG emissions standards or a more narrow repeal of the rule's carbon capture and storage requirements. We do not expect either alternative to have any impact on its current capital plan. Any final rule would likely be subject to litigation. See the Federal Deregulatory Actions discussion above for more information regarding potential deregulatory actions regarding this rule.
In April 2024, the EPA issued its final Mandatory Greenhouse Gas Reporting Rule, which includes updates to the global warming potentials to determine CO2 equivalency for threshold reporting and the addition of a new section regarding energy consumption. In its current form, the rule will impact the reporting required for our electric generation facilities, LDCs, and underground natural gas storage facilities. In May 2024, the EPA also issued its final rule to amend reporting requirements for petroleum and natural gas systems. Under the current form of this rule, new leak emission factors and reporting requirements for large release events will impact the reporting required for our LDCs and underground natural gas storage facilities; however, under the Federal Deregulatory Actions discussion above, in September 2025, the EPA released a proposal to amend the GHG Reporting Program to permanently remove program obligations for most source categories, including our generation facilities. The EPA is also proposing to suspend program reporting requirements that would be applicable to our underground storage, LNG, and transmission affiliates until 2034. We continue to monitor the status of these deregulatory actions.

Our capital plan includes the planned retirement of older, fossil-fueled generation, to be replaced with natural gas-fired generation and zero-carbon-emitting renewables. We have retired nearly 2,500 MWs of fossil-fueled generation since the beginning of 2018. We expect to retire approximately 900 MWs of additional coal-fired generation by the end of 2031. In conjunction with our new capital plan, we and the other co-owners of Columbia Units 1 and 2 currently plan to continue coal operations at these units through at least 2029, and continue to evaluate the conversion of both units to natural gas. See Note 7, Property, Plant, and Equipment, for more information related to Columbia Units 1 and 2 and our planned power plant retirements. We have a long-term goal to achieve net carbon-neutral electric generation by the end of 2050. We expect to achieve this goal by continuing to make operating refinements, retiring less efficient generating units, and executing our capital plan. As part of our path toward this goal, we started implementing co-firing with natural gas at the ERGS coal-fired units and at Weston Unit 4 in 2025. We expect to use coal only as a backup fuel by the end of 2030 and to be in a position to eliminate coal as an energy source by the end of 2032.

We also continue to focus on methane emission reductions by improving and upgrading our natural gas distribution systems and using RNG throughout our natural gas utility systems.

Water Quality

Clean Water Act Cooling Water Intake Structure Rule

The Clean Water Act Cooling Water Intake Structure Rule requires the location, design, construction, and capacity of cooling water intake structures at existing power plants reflect the BTA for minimizing adverse environmental impacts. The rule applies to all of our existing generating facilities with cooling water intake structures, except for the ERGS units, which were permitted and received a final BTA determination under the rules governing new facilities.

Other than OCPP Units 7 and 8, we have received final or interim BTA determinations for all generation facilities where applicable. We believe existing technology at OCPP Units 7 and 8 also meets the rule requirements for BTA and anticipate that the units will receive that determination when their Wisconsin Pollutant Discharge Elimination System permit is reissued, which is expected in 2026.

Steam Electric Effluent Limitation Guidelines

The EPA's 2024 Supplemental ELG Rule (the "2024 ELG Rule") established ZLD requirements for bottom ash transport water, flue gas desulfurization, and combustion residual leachate wastewaters at coal-fueled facilities. The 2024 ELG Rule also established a new subcategory, providing an alternative compliance pathway for facility owners that commit to the PCCC at a particular facility by December 31, 2034. In exchange for this commitment, ZLD technologies will not be required and less stringent standards will apply at applicable facilities. The 2024 ELG Rule also allows owners of coal-fired units who opted into a cessation of coal subcategory to operate beyond the end of 2034 if needed for reliability concerns (i.e., energy emergencies and reliability must run agreements) as determined by the United States DOE, a public utility commission, or independent system operator. Based on current electric generation resource planning, in December 2025, we filed Notice of Planned Participations to opt into the PCCC subcategory for certain of our past and current coal-fueled facilities.

In December 2025, the EPA published a final rule, effective March 2, 2026, that extends the deadline for facility owners to opt into a subcategory under the 2024 ELG Rule, allowing them more time to assess potential compliance pathways to continue producing low-cost electricity into the future while meeting wastewater standards.
When the deadline extension rule was proposed, the EPA also solicited public comments related to the economic achievability and technical availability of ZLD technologies. Additional ELG rulemaking is anticipated that may lead to substantive changes to the ZLD technology-based requirements established in the 2024 ELG Rule.

In addition, numerous parties have challenged the 2024 ELG Rule through litigation in SWEPCO v. U.S. EPA pending in the United States Court of Appeals for the Eighth Circuit, which has been held in abeyance since February 2025. The 2024 ELG Rule, as well as the deadline extension rule, remain in effect during the pendency of the legal challenge. The outcome of this case may affect our compliance plans.

Land Quality

Manufactured Gas Plant Remediation

We have identified sites at which our utilities or a predecessor company owned or operated a manufactured gas plant or stored manufactured gas. We have also identified other sites that may have been impacted by historical manufactured gas plant activities. Our natural gas utilities are responsible for the environmental remediation of these sites. We are working with the EPA as well as various state jurisdictions, as applicable, in our investigation and remediation planning and efforts. These sites are at various stages of investigation, monitoring, remediation, and closure.

The future costs for detailed site investigation, future remediation, and monitoring are dependent upon several variables including, among other things, the extent of remediation, changes in technology, and changes in regulation. Historically, our regulators have allowed us to recover incurred costs, net of insurance recoveries and recoveries from potentially responsible parties, associated with the remediation of manufactured gas plant sites. Accordingly, we have established regulatory assets for costs associated with these sites.

We have established the following regulatory assets and reserves for manufactured gas plant sites as of December 31:
(in millions)20252024
Regulatory assets for environmental remediation costs$566.0 $570.1 
Reserves for future environmental remediation484.1 445.8 

Coal Combustion Residuals Rule

An EPA rule for CCR that applies to landfills, historic fill sites, and projects where CCR was placed at a power plant site became effective in November 2024. The rule also regulates previously exempt closed landfills.

We anticipate this rule will have an impact on some of our coal ash landfills, requiring additional remediation that is not currently required under the state programs. We expect the cost of additional remediation would be recoverable through future rates.

The rule is being challenged through litigation pending in the D.C. Circuit Court of Appeals. In December 2025, the D.C. Circuit Court of Appeals granted the EPA's motion to extend the ongoing abeyance while the EPA reconsiders certain aspects of the rule. In February 2026, the EPA published a final rule extending certain deadlines and making various corrections to the 2024 CCR rule. The EPA has stated it plans to publish a new final rule by the end of 2026. See the Federal Deregulatory Actions discussion above for more information regarding potential deregulatory actions regarding this rule.

Renewables, Efficiency, and Conservation

Wisconsin Legislation

In 2005, Wisconsin enacted Act 141, which established a goal that 10% of all electricity consumed in Wisconsin be generated by renewable resources annually. WE and WPS have achieved their required renewable energy percentages of 8.27% and 9.74%, respectively, by constructing various wind and solar facilities, a biomass facility, and by also relying on renewable energy purchases. WE and WPS continue to review their renewable energy portfolios and acquire cost-effective renewables as needed to meet their requirements on an ongoing basis. The PSCW administers the renewable program related to Act 141, and each utility funds the program based on 1.2% of its annual retail operating revenues.
Michigan Legislation

In December 2016, Michigan enacted Act 342, which required 12.5% of the state's electric energy to come from renewables for 2019 and 2020, and energy optimization (efficiency) targets up to 1% annually. The renewable requirement increased to 15.0% for 2021 and beyond. UMERC was in compliance with its requirements under this statute as of December 31, 2025. The legislation continues to allow recovery of costs incurred to meet the standards and provides for ongoing review and revision to assure the measures taken are cost-effective.

In November 2023, Michigan enacted Acts 229, 231 and 235. The acts require electric providers to file a renewable energy plan every two years and to set renewable energy portfolio targets from now until 2040. The proposed renewable energy targets include 15% through 2029, 50% from 2030 through 2034, and 60% renewable energy by 2035 and thereafter. The bill also sets clean energy standards of 80% from 2035 through 2039 and 100% after 2040. The acts only allow natural gas to count as clean energy if it is accompanied with carbon capture and storage. The new acts also revise the requirement a utility must meet in filing its energy waste reduction plans. They require a utility to file a plan every two years until 2025, then every three years thereafter. In February 2025, we filed an AREP with the MPSC addressing UMERC's compliance with the Act 235 renewable portfolio standards. At the same time, we are working with a coalition of members of the Michigan legislature to seek exemption from Act 235 for our new RICE units. In December 2025, the MPSC issued an order denying UMERC's AREP, requiring UMERC to file a new AREP in October 2026.

Enforcement and Litigation Matters

We and our subsidiaries are involved in legal and administrative proceedings before various courts and agencies with respect to matters arising in the ordinary course of business. Although we are unable to predict the outcome of these matters, management believes that appropriate reserves have been established and that final settlement of these actions will not have a material impact on our financial condition or results of operations.
v3.25.4
Supplemental Cash Flow Information
12 Months Ended
Dec. 31, 2025
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]  
SUPPLEMENTAL CASH FLOW INFORMATION SUPPLEMENTAL CASH FLOW INFORMATION
The following table provides additional information regarding our statements of cash flows:
Year Ended December 31
(in millions)202520242023
Cash paid for interest, net of amount capitalized$858.5 $785.7 $653.4 
Cash received for income taxes, net
(281.3)(264.2)(58.9)
Significant non-cash investing and financing transactions:
Accounts payable related to construction costs232.0 285.7 171.3 
Common stock issued for stock-based compensation plans3.2 6.4 — 
Increase in receivables related to property damage insurance proceeds3.5 2.3 3.5 
Increase in receivables for corporate-owned life insurance proceeds 5.8 1.4 
Liabilities accrued for software licensing agreements21.1 0.2 — 

Cash, Cash Equivalents, and Restricted Cash

The statements of cash flows include our activity related to cash, cash equivalents, and restricted cash. The following table reconciles the cash, cash equivalents, and restricted cash amounts reported within the balance sheets at December 31 to the total of these amounts shown on the statements of cash flows:
(in millions)202520242023
Cash and cash equivalents$27.6 $9.8 $42.9 
Restricted cash included in other current assets9.1 5.3 70.1 
Restricted cash included in other long-term assets34.2 27.1 52.2 
Cash, cash equivalents, and restricted cash$70.9 $42.2 $165.2 

Our restricted cash primarily consisted of the following:

Cash held in the Integrys rabbi trust, which is used to fund participants' benefits under the Integrys deferred compensation plan and certain Integrys non-qualified pension plans.
Cash on deposit in financial institutions that is restricted to satisfy the requirements of certain debt agreements at WECI Wind Holding I, WECI Wind Holding II, WECI Energy Holding III, and WEPCo Environmental Trust.

Cash related to WECI's ownership interests in certain renewable generation projects. These projects are required to deposit into an escrow account in order to fund future decommissioning.
v3.25.4
Regulatory Environment
12 Months Ended
Dec. 31, 2025
Regulated Operations [Abstract]  
REGULATORY ENVIRONMENT REGULATORY ENVIRONMENT
Wisconsin Electric Power Company, Wisconsin Public Service Corporation, and Wisconsin Gas LLC

Very Large Customer and Bespoke Resources Tariffs

In March 2025, WE filed an application with the PSCW requesting approval to implement a VLC Tariff and a Bespoke Resources Tariff. WE subsequently filed testimony in October 2025 slightly modifying the initial proposals. Under these proposed inter-connected tariffs, VLCs (new customers using 500 MWs or more, such as large data centers) will have access to reliable power to meet their needs and will directly pay for the electricity they consume, along with the power plants and distribution facilities built to serve them and operating and transmission costs allocated to their usage. The proposed tariffs are designed so that the costs associated with these VLCs are not subsidized by or shifted to residential or business customers.

The two new tariffs will work in tandem as VLCs will be required to sign a service agreement and subscribe to a portion of one or more "Bespoke Resources," including renewable generation facilities, battery storage, and natural gas generation units. Under these agreements, if a VLC terminates or downsizes its plans, it will still be required to pay for the Bespoke Resources and dedicated distribution facilities that have been built to support its forecasted load, unless the facilities can be repurposed, subject to PSCW approval. Service agreements under the Bespoke Resources Tariff will be effective for the depreciable life of the resource, except for wind or solar resources which will have a term of 20 years. As currently proposed, the ROE (can range from 10.48% to 10.98% as agreed upon with the customer) and equity ratio (57%) will both be fixed for the entire term of the agreement, and the revenue and costs recovered through the tariffs will be excluded from future rate case proceedings and earnings sharing mechanisms.

We expect a decision from the PSCW in the second quarter of 2026. Prior to the PSCW approving the tariffs, for infrastructure investments that have not received regulatory approval, WE requires VLCs to enter into payment and cancellation agreements which obligate the VLC to reimburse WE for all costs associated with projects, including any associated costs incurred by ATC for transmission infrastructure projects, requested by the customer until service agreements are executed under the approved tariffs. Reimbursement is required if, among other things, the VLC terminates the payment and cancellation agreement or reduces its anticipated load, or regulatory approval is not received for the construction of a project.

2025 and 2026 Rates

In April 2024, WE, WPS, and WG filed requests with the PSCW to increase their retail electric, natural gas, and steam rates, as applicable. The primary drivers of the requested increases in electric rates were continued capital investments to transition our generation fleets from coal to renewables and natural gas-fueled generation, increased costs driven by higher inflation and interest rates, and the recovery of regulatory assets previously approved by the PSCW. The requested increases in natural gas rates were driven by the companies' ongoing capital investments in reliability and safety projects, including LNG storage facilities, as well as the impacts from higher inflation and increased interest rates.
In December 2024, the PSCW issued final written orders approving electric, natural gas, and steam base rate increases, effective January 1, 2025 and 2026, as applicable. The final written orders reflected the following:
WEWPSWG
2025 rate increase
Electric (1)
$144.0  million/4.2%$55.1  million/4.5%N/A
Gas$41.3  million/7.1%$14.9  million/3.8%$34.5  million/4.2%
Steam$1.5  million/5.0%N/AN/A
2026 rate increase (2)
Electric (1)
$169.5  million/4.5%$30.0  million/2.3%N/A
Gas$29.8  million/4.5%$13.5  million/3.1%$23.5  million/2.6%
ROE9.8%9.8%9.8%
Common equity component average on a financial basis53.0%53.0%53.0%

(1)    Amounts reflect the impact to our Wisconsin retail electric operations and include the incremental decrease resulting from updated fuel costs.

(2)    The 2026 rate increases are incremental to the previously authorized revenue plus the approved rate increases for 2025.

Effective January 1, 2025, WE was required to implement a new earnings sharing mechanism, under which, if WE earns above its authorized ROE: (i) it retains 100.0% of earnings for the first 15 basis points above the authorized ROE; (ii) 50.0% of the next 25 basis points is required to be refunded to ratepayers; and (iii) 100.0% of any remaining excess earnings is required to be refunded to ratepayers.

WPS and WG were required to maintain their then current earnings sharing mechanism. Under this mechanism, if the utility earns above its authorized ROE: (i) the utility retains 100.0% of earnings for the first 15 basis points above the authorized ROE; (ii) 50.0% of the next 60 basis points is required to be refunded to ratepayers; and (iii) 100.0% of any remaining excess earnings is required to be refunded to ratepayers.

2024 Limited Rate Case Re-Opener

In accordance with their rate orders approved by the PSCW in December 2022, WE, WPS, and WG filed requests for limited electric and natural gas rate case re-openers, as applicable, with the PSCW in May 2023. The WE and WPS limited electric rate case re-openers included updated fuel costs and revenue requirements for the generation projects that were previously approved by the PSCW and were placed into service in 2023 or were expected to be placed into service in 2024. WE's limited electric re-opener also included the projected savings from the retirement of the OCPP Units 5 and 6, which were retired in May 2024. WE and WG also filed a request for a limited natural gas rate case re-opener to reflect the additional revenue requirements associated with their previously approved LNG projects. WE's and WG's LNG projects were placed into service in November 2023 and February 2024, respectively.

In December 2023, the PSCW issued final written orders approving electric and natural gas rate increases and decreases, effective January 1, 2024. The final orders reflected the following:
WEWPSWG
2024 incremental rate increases (decreases)
Electric (1)
$82.2  million/2.5%$(32.7) million/(2.6)%N/A
Gas$23.9  million/4.5%N/A$21.6  million/2.8%

(1)    Amounts reflect the impact to our Wisconsin retail electric operations and include any incremental increases (WE) or decreases (WPS) resulting from updated fuel costs.

The utilities' ROE and common equity component averages were not addressed in the limited rate case re-openers.

2023 and 2024 Rates

In April 2022, WE, WPS, and WG filed requests with the PSCW to increase their retail electric, natural gas, and steam rates, as applicable. These requests were updated in July 2022 to reflect new developments that impacted the original proposals. The requested increases in electric rates were driven by capital investments in new wind, solar, and battery storage; capital investments
in natural gas generation; reliability investments, including grid hardening projects to bury power lines and strengthen WE's distribution system against severe weather; and changes in wholesale business with other utilities. Many of these investments had already been approved by the PSCW. The requested increases in natural gas rates primarily related to capital investments previously approved by the PSCW, including LNG storage for our natural gas distribution system.

In December 2022, the PSCW issued final written orders approving electric, natural gas, and steam base rate increases, effective January 1, 2023. The final orders reflected the following:
WEWPSWG
2023 base rate increase
Electric$283.5  million/9.1%$120.5  million/9.8%N/A
Gas$46.1  million/9.6%$26.4  million/7.1%$46.5  million/6.4%
Steam$7.6  million/35.3%N/AN/A
ROE9.8%9.8%9.8%
Common equity component average on a financial basis53.0%53.0%53.0%

In addition to the above, the final orders included the following terms:

The utilities kept their then current earnings sharing mechanisms, under which, if a utility earned above its authorized ROE: (i) the utility retained 100.0% of earnings for the first 15 basis points above the authorized ROE; (ii) 50.0% of the next 60 basis points was refunded to ratepayers; and (iii) 100.0% of any remaining excess earnings was required to be refunded to ratepayers.
WE and WPS were required to complete an analysis of alternative recovery scenarios for generating units that will be retired prior to the end of their useful life.
WE and WPS were not allowed to propose any changes to their real time pricing rates for large commercial and industrial electric customers through the end of 2024.
WE and WPS were required to lower monthly residential and small commercial electric customer fixed charges by $1.00 and $3.33, respectively, from previously authorized rates.
WE and WPS were required to offer an additional voluntary renewable energy pilot for commercial and industrial customers.
WE and WPS were required to continue to work with PSCW staff and other interested parties to develop alternative low income assistance programs. WE and WPS also collectively contributed $4.0 million to the Keep Wisconsin Warm Fund.
WE, WPS, and WG were required to implement escrow accounting treatment for pension and OPEB costs. As a result, they defer as a regulatory asset or liability, the difference between actual pension and OPEB costs and those included in rates until recovery or refund is authorized in a future rate proceeding.
As discussed above, WE and WPS were authorized to file a limited electric rate case re-opener for 2024, and WE and WG were authorized to file a limited natural gas rate case re-opener for 2024.

The Peoples Gas Light and Coke Company and North Shore Gas Company

2026 Rate Application

In January 2026, PGL and NSG filed requests with the ICC to increase their natural gas base rates. They are requesting rate increases of $201.3 million (20.95%) and $12.7 million (12.2%), respectively. The requested rate increases are primarily driven by capital investments made to strengthen the safety and reliability of each utility’s natural gas distribution system. PGL's rate request includes the estimated revenue requirements associated with its PRP projects. As discussed below, projects completed under PGL's PRP are to meet the ICC's directive to retire all cast and ductile iron pipe that has a diameter under 36 inches by January 1, 2035. PGL's rate request includes the revenue requirements associated with approximately $360 million of capital investments planned under its PRP in 2027. Higher operating costs, driven by inflation, and increases in the cost of capital, also drove the requested rate increases. Both companies are requesting an ROE of 10.10% and a common equity component average of 54.0%.

An ICC decision is anticipated in the fourth quarter of 2026, with new rates expected to be effective by January 1, 2027.
2023 Rate Order

In January 2023, PGL and NSG filed requests with the ICC to increase their natural gas base rates. The requested rate increases were primarily driven by capital investments made to strengthen the safety and reliability of each utility’s natural gas distribution system. PGL was also seeking to recover costs incurred to upgrade its natural gas storage field and operations facilities and to continue improving customer service. PGL did not request an extension of the QIP rider as PGL returned to the traditional rate making process to recover the costs of necessary infrastructure improvements.

In November 2023, the ICC issued final written orders approving base rate increases for PGL and NSG. The written orders were subsequently amended for various technical corrections. The amended written orders approved the following base rate increases:

A $304.6 million (43.5%) base rate increase for PGL’s natural gas customers, effective December 1, 2023. This amount includes the recovery of costs that were previously being recovered under its QIP rider.

An $11.0 million (11.6%) base rate increase for NSG’s natural gas customers. The new rates at NSG were not effective until February 1, 2024 as changes were required to NSG's billing system as a result of the final rate order.

The ICC approved an authorized ROE of 9.38% for both PGL and NSG, and set the common equity component average at 50.79% and 52.58% for PGL and NSG, respectively.

As part of its decisions, the ICC, among other things, disallowed $236.2 million of capital costs related to the construction and improvement of PGL’s shops and facilities and $1.7 million of capital costs related to NSG's construction of a gas infrastructure project. In addition, the ICC ordered PGL to pause spending on its projects to upgrade its natural gas delivery system until the ICC had a proceeding to determine the optimal method for replacing aging natural gas infrastructure and a prudent investment level.

In December 2023, PGL and NSG filed an application for rehearing with the ICC requesting reconsideration of various issues in the ICC's November 2023 written orders. The ICC granted PGL and NSG a limited-scope rehearing focused exclusively on the authorized spending for the completion of projects to upgrade PGL's natural gas delivery system that started in 2023 and emergency repairs needed to ensure the safety and reliability of the delivery system. In May 2024, the ICC issued a written order on the rehearing. The order approved $28.5 million of additional spending for emergency work, representing a $1.6 million increase to PGL's annual revenue requirement.

As the ICC did not grant a rehearing on the disallowance of PGL's and NSG's capital costs, we recorded a $178.9 million non-cash impairment of our property, plant, and equipment during the fourth quarter of 2023. This amount included $177.2 million of previously incurred disallowed costs at PGL related to its shops and facilities, and the $1.7 million of capital costs disallowed at NSG. The remaining disallowance of capital costs at PGL related to expected future spend.

In June 2024, PGL and NSG filed a petition with the Illinois Appellate Court for review of the November 2023 and May 2024 orders. The appeal includes the ICC's $237.9 million combined disallowance of capital costs at PGL and NSG discussed above, along with the $116.0 million disallowance of capital investments needed to meet safety and reliability requirements of PGL's natural gas delivery system. Although the ICC ordered PGL to complete safety and reliability work in 2024, it denied the recovery of these costs in the current rates.

In accordance with the November 2023 rate order, the ICC initiated a proceeding in January 2024 to determine the optimal method and a prudent investment level for replacing aging natural gas infrastructure. In February 2025, the ICC issued an order setting expectations for PGL's prospective operations. The ICC directed us to focus on retiring all cast and ductile iron pipe that has a diameter under 36 inches by January 1, 2035. The ICC also indicated that failure to comply with this directive could subject us to civil penalties under Illinois statute. PGL is working to retire this cast and ductile iron pipe through its PRP. Costs incurred under the PRP will be evaluated for prudency by the ICC in future rate cases. In addition, the program will be overseen by a safety monitor hired by the ICC. As discussed above, PGL initiated a general rate case proceeding in January 2026, which we anticipate will provide further regulatory clarity before we significantly increase our spend associated with the PRP.
Illinois Riders

Uncollectible Expense Adjustment Rider

The rates of PGL and NSG include a UEA rider for cost recovery or refund of uncollectible expense based on the difference between actual uncollectible write-offs and the amounts recovered in rates. The UEA rider is subject to an annual reconciliation whereby costs are reviewed for accuracy and prudency by the ICC. In May 2023, the ICC issued a written order on PGL's and NSG's 2018 UEA rider reconciliation. The order required a $15.4 million and $0.7 million refund to customers at PGL and NSG, respectively. These amounts were refunded over a period of nine months, which began on September 1, 2023. Upon appeal by PGL and NSG, the Illinois Appellate Court affirmed the ICC order and the related disallowance. The Illinois Supreme Court denied a subsequent petition for review and reversal of the order in March 2025.

As of December 31, 2025, there can be no assurance that all costs incurred under the UEA rider during the open reconciliation years will be deemed recoverable by the ICC. Future disallowances by the ICC could be material. The combined annual costs of PGL and NSG included in the rider, which reflect uncollectible write-offs in excess of what is recovered in base rates, have ranged from $10 million to $40 million. However, see Uncollectible Expense Adjustment and Qualifying Infrastructure Plant Riders Settlement below for information on a proposed settlement that would resolve all open proceedings.

Qualifying Infrastructure Plant Rider

In July 2013, Illinois Public Act 98-0057, The Natural Gas Consumer, Safety & Reliability Act, became law. This law provides natural gas utilities with a cost recovery mechanism that allows collection, through a surcharge on customer bills, of prudently incurred costs to upgrade Illinois natural gas infrastructure. In January 2014, the ICC approved a QIP rider for PGL, which was in effect until December 1, 2023. As discussed above, PGL has returned to the traditional rate-making process for recovery of these costs, and they are now included in PGL's base rates.

Costs previously incurred under PGL's QIP rider are still subject to an annual reconciliation whereby costs are reviewed for accuracy and prudency. In August 2024, the ICC issued a final order on PGL's 2016 annual reconciliation, which included a disallowance of $14.8 million of certain capital costs. PGL recorded a pre-tax charge to income of $25.3 million during the third quarter of 2024 related to the disallowance and the previously recognized return on and of these investments. The charge was recorded on the income statement as a $12.9 million reduction in revenues for the amounts previously collected from customers, a $12.1 million increase to operating expenses for the impairment of PGL's property, plant, and equipment, and a $0.3 million increase to interest expense related to the amounts due to customers. In October 2024, PGL filed a petition with the Illinois Appellate Court for review of the ICC's August 2024 order; however, in January 2026, PGL filed an unopposed motion to stay the appeal, which was granted by the court.

PGL's QIP reconciliations from 2017 through 2023 are still pending. Future disallowances by the ICC could be material. The aggregate capital costs included in the rider during the open reconciliation years, along with any previously recognized return on these investments, totaled approximately $3.0 billion as of December 31, 2025. However, see Uncollectible Expense Adjustment and Qualifying Infrastructure Plant Riders Settlement below for information on a proposed settlement that would resolve all open proceedings.

Uncollectible Expense Adjustment and Qualifying Infrastructure Plant Riders Settlement

In February 2026, PGL and NSG agreed on the terms of a proposed settlement with the Illinois Attorney General that, if approved by the ICC, would resolve all open proceedings related to the UEA and QIP riders. PGL and NSG agreed to refund $49.0 million and $1.0 million, respectively, to customers as bill credits over a period of three years between 2026 and 2028 to resolve the open UEA proceedings. In order to resolve the open QIP proceedings, PGL agreed to permanently remove $130.0 million of qualified infrastructure investment costs from rate base starting in 2027 and to refund $75.0 million to customers as bill credits over a period of three years between 2026 and 2028. As a result of this agreement, we recorded a $205.0 million charge to income during the fourth quarter of 2025. The charge was recorded as a $130.0 million impairment to PGL's net property, plant, and equipment and a $75.0 million reduction to revenues. The total of the rate base reduction and the obligation to refund amounts to customers through bill credits recorded on our balance sheet at December 31, 2025 is $255.0 million. This includes the $205.0 million charge to income recorded during 2025 and a $50.0 million charge to income recorded in prior years. This proposed settlement is subject to ICC approval following a public review process.
Minnesota Energy Resources Corporation

2023 Rate Order

In November 2022, MERC initiated a rate proceeding with the MPUC to increase its retail natural gas base rates. In December 2022, the MPUC approved MERC's request for interim rates totaling $37.0 million, subject to refund. The interim rates went into effect on January 1, 2023.

In November 2023, the MPUC issued a written order approving a settlement agreement MERC reached with certain intervenors. The settlement agreement reflected a natural gas base rate increase of $28.8 million (7.1%), along with a 9.65% ROE and a common equity component average of 53.0%. The natural gas rate increase was primarily driven by increased capital investments as well as inflationary pressure on operating costs. Under the terms of the settlement agreement, MERC will continue the use of its decoupling mechanism for residential customers, and it will be expanded to include certain small commercial and industrial customers.

Final rates went into effect on March 1, 2024. MERC’s customers were entitled to an $8.9 million refund due to the interim rate increase exceeding the final approved rate increase, which was retroactive to January 1, 2023. These amounts were refunded to customers during the second quarter of 2024.

Michigan Gas Utilities Corporation

2026 Rate Application

On December 19, 2025, MGU provided notification to the MPSC of its intent to file an application requesting an increase to its natural gas rates. The application is expected to be filed in March 2026 and to request new rates be effective January 1, 2027. MGU is currently in the process of evaluating its rate request.

2024 Rate Order

In March 2024, MGU filed a request with the MPSC to increase its retail natural gas base rates. In September 2024, the MPSC issued a final order approving a settlement agreement, which authorized MGU to increase its natural gas base rates by $7.0 million (3.88%). The rate increase was primarily driven by inflationary pressure on capital projects and operating and maintenance costs and the significant increase in interest rates over the past few years. The rate increase reflected a 9.86% ROE and a common equity component average of 50.0%. The new rates became effective January 1, 2025. The order also authorized MGU to defer any expenses incurred to implement the PHMSA's proposed rulemaking titled "Gas Pipeline Leak Detection and Repair."

2023 Rate Order

In March 2023, MGU filed a request with the MPSC to increase its retail natural gas base rates. In August 2023, the MPSC issued a written order approving a comprehensive settlement that resolved all issues in MGU's rate case. The key terms of the settlement agreement included:

a natural gas base rate increase of $9.9 million (4.7%);
an ROE of 9.8%;
a common equity component average of 51.0%; and,
a continuation of the existing MRP rider, effective January 1, 2025 through 2027, including forecasted increased costs for those projects. MRP costs were recovered in base rates in 2024.

The rate increase was primarily driven by capital investments made to strengthen the safety and reliability of MGU's natural gas distribution system and to provide service to additional customers. Inflationary pressure on operating costs also contributed to the rate increase. The new rates were effective January 1, 2024.
Upper Michigan Energy Resources Corporation

Amended Renewable Energy Plan

In accordance with Michigan Public Act 235, UMERC filed an AREP with the MPSC in February 2025. UMERC's AREP addressed its compliance with the Act 235 renewable portfolio standards and its proposal to recover the projected compliance costs through an incremental renewable energy surcharge. The projected compliance costs included the purchase of Michigan-sourced renewable energy credits and the revenue requirements for UMERC's previously approved investment in Renegade, a 100 MW utility-scale solar-powered electric generating facility, and any other incremental renewable generation resources required to meet the Act 235 renewable portfolio standards. On December 18, 2025, the MPSC issued an order denying UMERC's AREP and requiring UMERC to file a new AREP by October 15, 2026.

Renegade is currently interconnected and delivering power to MISO, and it is expected to achieve commercial operation in the first quarter of 2026. The estimated cost of Renegade is approximately $226 million. As UMERC's proposal to recover the annual revenue requirement of Renegade through a renewable energy surcharge was denied, UMERC will recover a portion of these costs through its power supply cost recovery mechanism, and the MPSC advised UMERC to seek deferral accounting treatment for the remainder. UMERC filed its request for deferral accounting with the MPSC on January 27, 2026.

2024 Rate Order

In May 2024, UMERC filed a request with the MPSC to increase its electric base rates for non-mine customers. In October 2024, the MPSC issued a final order approving a settlement agreement, which authorized UMERC to increase electric base rates for non-mine customers by $6.6 million (8.2%). The new rates became effective January 1, 2025. The rate increase reflected a 9.86% ROE and a common equity component average of 50.0%. The rate increase was primarily driven by the construction of the now in-service RICE generation facilities located in the Upper Peninsula of Michigan and a reduction in sales volumes resulting from the implementation of limited retail choice since UMERC’s predecessor utilities last reset rates. A reduction of operation and maintenance costs partially offset these impacts.
v3.25.4
Other Income, Net
12 Months Ended
Dec. 31, 2025
Other Income and Expenses [Abstract]  
OTHER INCOME, NET OTHER INCOME, NET
Total other income, net was as follows for the years ended December 31:
(in millions)202520242023
AFUDC-Equity$99.8 $59.8 $59.1 
Gains from investments held in rabbi trust8.1 11.7 13.7 
Interest income5.9 17.2 3.9 
Non-service components of net periodic benefit costs2.7 83.7 97.7 
Earnings (losses) from equity method investments (1)
(10.4)4.7 (1.1)
Other, net1.8 1.1 4.4 
Other income, net$107.9 $178.2 $177.7 

(1)    Amounts do not include equity earnings of transmission affiliates as those earnings are shown as a separate line item on the income statements.
v3.25.4
New Accounting Pronouncements
12 Months Ended
Dec. 31, 2025
Accounting Standards Update and Change in Accounting Principle [Abstract]  
NEW ACCOUNTING PRONOUNCEMENTS NEW ACCOUNTING PRONOUNCEMENTS
Improvements to Interim Reporting

In December 2025, the FASB issued ASU No. 2025-11, Interim Reporting (Topic 270) Narrow-Scope Improvements. The amendments clarify interim disclosure requirements and the applicability of Topic 270. The amendments include a comprehensive list of interim disclosures that are currently required under GAAP. The amendments also include a disclosure principle that requires entities to disclose events since the end of the last annual reporting period that have a material impact on the entity. Finally, the amendments clarify the types of interim reporting and the form and content of interim financial statements in accordance with GAAP. The amendments are effective for interim periods within annual periods beginning after December 15, 2027, with early adoption permitted. We are currently evaluating the impact this guidance may have on our financial statements and related disclosures.
Accounting for Government Grants

In December 2025, the FASB issued ASU No. 2025-10, Government Grants (Topic 832) Accounting for Government Grants Received by Business Entities. The amendments establish the accounting for a government grant received by a business entity, including guidance for a grant related to an asset and a grant related to income. The amendments also require disclosures, including the nature of the government grant received, the accounting policies used to account for the grant, and significant terms and conditions of the grant. The amendments are effective for annual periods beginning after December 15, 2028, and interim periods within those annual periods, with early adoption permitted. We are currently evaluating the impact this guidance may have on our financial statements and related disclosures.

Disaggregation of Income Statement Expenses
In November 2024, the FASB issued ASU No. 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40) Disaggregation of Income Statement Expenses. The amendments require disclosure of certain costs and expenses in the notes to financial statements, which are disaggregated from relevant expense captions on the income statement. The amendments also require additional qualitative disclosures of the amounts remaining in relevant expense captions that are not separately disaggregated quantitatively. Finally, the amendments require disclosure of the total amount of selling expenses and, in annual reporting periods, an entity's definition of selling expenses. The amendments are effective for annual periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027, with early adoption permitted. We plan to adopt these amendments beginning with our fiscal year ending on December 31, 2027, and are currently evaluating the impact this guidance may have on our financial statements and related disclosures.
v3.25.4
Schedule I - Condensed Parent Company Financial Statements
12 Months Ended
Dec. 31, 2025
Condensed Financial Information Disclosure [Abstract]  
SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS
SCHEDULE I
CONDENSED PARENT COMPANY FINANCIAL STATEMENTS
WEC ENERGY GROUP, INC. (PARENT COMPANY ONLY)
A. INCOME STATEMENTS
Year Ended December 31
(in millions)202520242023
Operating expenses$3.6 $5.4 $2.5 
Equity earnings of subsidiaries1,819.2 1,724.2 1,502.5 
Other income, net26.5 32.0 19.6 
Interest expense399.3 333.6 260.8 
Gain on debt extinguishments (23.1)— 
Income before income taxes1,442.8 1,440.3 1,258.8 
Income tax benefit114.7 86.9 72.9 
Net income attributed to common shareholders$1,557.5 $1,527.2 $1,331.7 

The accompanying Notes to Condensed Parent Company Financial Statements are an integral part of these financial statements.
B. STATEMENTS OF COMPREHENSIVE INCOME
Year Ended December 31
(in millions)202520242023
Net income attributed to common shareholders$1,557.5 $1,527.2 $1,331.7 
Other comprehensive income (loss), net of tax
Derivatives accounted for as cash flow hedges
Reclassification of realized derivative gains to net income, net of tax(0.2)(0.3)(0.3)
Defined benefit plans
Pension and OPEB adjustments arising during the period, net of tax0.2 — (0.2)
Amortization of pension and OPEB costs included in net periodic benefit cost, net of tax0.1 0.1 0.1 
Defined benefit plans, net0.3 0.1 (0.1)
Other comprehensive income (loss) from subsidiaries, net of tax0.1 0.1 (0.5)
Other comprehensive income (loss), net of tax0.2 (0.1)(0.9)
Comprehensive income attributed to common shareholders$1,557.7 $1,527.1 $1,330.8 

The accompanying Notes to Condensed Parent Company Financial Statements are an integral part of these financial statements.
C. BALANCE SHEETS
At December 31
(in millions)20252024
Assets
Current assets
Cash and cash equivalents$0.1 $— 
Accounts receivable from related parties3.2 2.7 
Notes receivable from related parties63.0 63.2 
Prepaid income taxes14.9 16.3 
Current assets81.2 82.2 
Long-term assets
Investments in subsidiaries22,222.1 19,809.0 
Note receivable from WECI460.0 300.0 
Other56.0 23.2 
Long-term assets22,738.1 20,132.2 
Total assets$22,819.3 $20,214.4 
Liabilities and Equity
Current liabilities
Short-term debt$702.9 $382.7 
Current portion of long-term debt1,350.0 620.0 
Accounts payable to related parties5.0 3.1 
Notes payable to related parties778.4 580.9 
Other69.5 69.4 
Current liabilities2,905.8 1,656.1 
Long-term liabilities
Long-term debt6,280.2 6,135.4 
Other19.7 28.0 
Long-term liabilities6,299.9 6,163.4 
Common shareholders' equity13,613.6 12,394.9 
Total liabilities and equity$22,819.3 $20,214.4 

The accompanying notes to Condensed Parent Company Financial Statements are an integral part of these financial statements.
D. STATEMENTS OF CASH FLOWS
Year Ended December 31
(in millions)202520242023
Operating activities
Net income attributed to common shareholders$1,557.5 $1,527.2 $1,331.7 
Reconciliation to cash provided by operating activities
Equity income in subsidiaries, net of distributions(669.2)(931.8)(566.8)
Deferred income taxes, net(21.5)(2.1)(3.8)
Gain on debt extinguishments (23.1)— 
Change in –
Accounts receivable from related parties(0.5)— (2.0)
Prepaid income taxes1.4 (16.3)35.4 
Other current assets 0.2 (0.1)
Accounts payable to related parties1.9 0.2 0.9 
Accrued interest1.3 (3.6)42.1 
Other current liabilities(0.8)(0.6)(0.7)
Other, net18.4 15.5 14.4 
Net cash provided by operating activities888.5 565.6 851.1 
Investing activities
Capital contributions to subsidiaries(2,277.7)(1,273.9)(1,807.4)
Return of capital from subsidiaries537.9 846.6 175.2 
Short-term notes receivable from related parties, net0.2 (47.2)14.9 
Issuance of long-term note receivable to WECI(160.0)— — 
Other, net(14.7)— — 
Net cash used in investing activities(1,914.3)(474.5)(1,617.3)
Financing activities
Exercise of stock options39.1 23.7 6.3 
Issuance of common stock, net761.9 163.4 — 
Purchase of common stock(1.3)(3.2)(16.6)
Dividends paid on common stock(1,147.8)(1,056.2)(984.2)
Issuance of long-term debt1,500.0 2,475.0 2,050.0 
Retirement of long-term debt(620.0)(1,473.7)(700.0)
Change in commercial paper320.2 (314.3)297.3 
Short-term notes payable to related parties, net197.5 121.3 127.1 
Payments for debt extinguishment and issuance costs(23.7)(27.0)(13.3)
Other, net (0.1)(0.4)
Net cash provided by (used in) financing activities1,025.9 (91.1)766.2 
Net change in cash and cash equivalents0.1 — — 
Cash and cash equivalents at beginning of year — — 
Cash and cash equivalents at end of year$0.1 $— $— 

The accompanying Notes to Condensed Parent Company Financial Statements are an integral part of these financial statements.
SCHEDULE I
CONDENSED PARENT COMPANY FINANCIAL STATEMENTS
WEC ENERGY GROUP, INC. (PARENT COMPANY ONLY)

E. NOTES TO PARENT COMPANY FINANCIAL STATEMENTS

NOTE 1—SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

For Parent Company only presentation, investments in subsidiaries are accounted for using the equity method. We use the cumulative earnings approach for classifying distributions received in the statements of cash flows.

The condensed Parent Company financial statements and notes should be read in conjunction with the consolidated financial statements and notes of WEC Energy Group, Inc. appearing in this Annual Report on Form 10-K.

NOTE 2—CASH DIVIDENDS RECEIVED FROM SUBSIDIARIES

Dividends received from our subsidiaries during the years ended December 31 were as follows:
(in millions)202520242023
WE$600.0 $240.0 $370.0 
We Power175.6 225.3 192.8 
WECI (1)
152.5 127.2 93.7 
WG100.0 80.0 171.0 
ATC Holding73.9 104.6 86.8 
UMERC23.0 15.0 21.0 
Bluewater20.0 — — 
WEC Investments, LLC4.3 — — 
Wispark (2)
0.7 0.3 0.4 
Total$1,150.0 $792.4 $935.7 

(1)    We also received amounts classified as return of capital of $534.5 million, $843.9 million, and $171.6 million from WECI during the years ended December 31, 2025, 2024, and 2023, respectively.

(2)    We also received amounts classified as return of capital of $2.9 million, $2.7 million, and $3.6 million from Wispark during the years ended December 31, 2025, 2024, and 2023, respectively.

NOTE 3—LONG-TERM DEBT

The following table shows the future maturities of our long-term debt outstanding as of December 31, 2025:
(in millions)
2026$1,350.0 
20271,762.5 
20281,850.0 
2029862.5 
2030300.0 
Thereafter1,550.0 
Total$7,675.0 

WECC is our subsidiary and has $50.0 million of long-term notes outstanding. In a Support Agreement between WECC and us, we agreed to make sufficient liquid asset contributions to WECC to permit WECC to service its debt obligations as they become due.
NOTE 4—FAIR VALUE MEASUREMENTS

The following table shows the financial instruments included on our balance sheets that are not recorded at fair value as of December 31:
20252024
(in millions)Carrying AmountFair ValueCarrying AmountFair Value
Long-term notes receivable from WECI$460.0 $464.6 $300.0 $300.0 
Long-term debt, including current portion7,630.2 7,922.9 6,755.4 6,776.0 

The fair value of our long-term notes receivable and long-term debt are categorized within Level 2 of the fair value hierarchy.

NOTE 5—GUARANTEES

The following table shows our outstanding guarantees on behalf of our subsidiaries:
Total Amounts Committed at December 31, 2025Expiration
(in millions)
Less Than 1 Year1 to 3 YearsOver 3 Years
Guarantees supporting business operations (1)
$309.6 $74.9 $11.0 $223.7 
Standby letters of credit (2)
140.9 30.7 30.0 80.2 
Surety bonds (3)
46.5 46.4 0.1 — 
Other guarantees (4)
9.6 — — 9.6 
Total guarantees$506.6 $152.0 $41.1 $313.5 

(1)    Consists of $233.5 million, $39.0 million, $17.0 million, $10.1 million, $6.0 million, and $4.0 million of guarantees to support the business operations of WECI, MERC, MGU, Bluewater, NSG, and UMERC, respectively.

(2)    At our request or the request of our subsidiaries, financial institutions have issued standby letters of credit for the benefit of third parties that have extended credit to our subsidiaries. These amounts are not reflected on our balance sheets.

(3)    Primarily for environmental remediation, workers compensation self-insurance programs, and obtaining various licenses, permits, and rights-of-way. These amounts are not reflected on our balance sheets.

(4)    Related to workers compensation coverage for which a liability was recorded on our balance sheets.

NOTE 6—SUPPLEMENTAL CASH FLOW INFORMATION
(in millions)202520242023
Cash paid for interest$382.8 $324.2 $209.1 
Cash received for income taxes, net(92.9)(66.7)(104.5)
Significant non-cash equity transaction:
Issuance of long-term note receivable to WECI 300.0 430.0 
Repayment of long-term note receivable to WECI 430.0 — 

NOTE 7—SHORT-TERM NOTES RECEIVABLE FROM RELATED PARTIES

The following table shows our outstanding short-term notes receivable from related parties as of December 31:
(in millions)20252024
UMERC$62.9 $63.2 
Wispark0.1 — 
Total$63.0 $63.2 
NOTE 8—SHORT-TERM NOTES PAYABLE TO RELATED PARTIES

The following table shows our outstanding short-term notes payable to related parties as of December 31:
(in millions)20252024
Integrys$515.3 $327.0 
WECC112.0 111.1 
WBS97.3 90.4 
Bluewater53.8 52.4 
Total$778.4 $580.9 
v3.25.4
Schedule II - Valuation and Qualifying Accounts
12 Months Ended
Dec. 31, 2025
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]  
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS
SCHEDULE II
WEC ENERGY GROUP, INC.
VALUATION AND QUALIFYING ACCOUNTS
Allowance for Doubtful Accounts
(in millions)
Balance at Beginning of Period
Expense (1)
Deferral
Net
Write-offs (2)
Balance at End of Period
December 31, 2025$162.8 $142.8 $(23.8)$(133.1)$148.7 
December 31, 2024$193.5 $104.9 $35.8 $(171.4)$162.8 
December 31, 2023199.3 72.0 88.3 (166.1)193.5 

(1)    Net of recoveries.

(2)    Represents amounts written off to the reserve, net of adjustments to regulatory assets.
v3.25.4
Insider Trading Arrangements
3 Months Ended
Dec. 31, 2025
Trading Arrangements, by Individual  
Rule 10b5-1 Arrangement Adopted false
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
v3.25.4
Cybersecurity Risk Management and Strategy Disclosure
12 Months Ended
Dec. 31, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]  
Cybersecurity Risk Management Processes Integrated [Flag] true
Cybersecurity Risk Management Processes Integrated [Text Block]
Our cybersecurity-related risks are managed through monitoring, defense and response tools, audits and assessments of the program’s effectiveness, industry collaboration, and employee training and awareness. Our cybersecurity risk management program utilizes the cybersecurity framework and maturity models from the National Institute of Standards and Technology and the DOE to continually assess its maturity. This includes regular internal security audits and vulnerability assessments, as well as regular engagement with third-party security experts for external assessments of our security controls, including technical, physical, and social aspects. To better comprehend the scope and magnitude of any active threats to our industry and nation and their potential impact on our IT/OT systems, we communicate with other utility companies, government agencies, and other sectors of the economy concerning cybersecurity incidents. All employees are required to complete training annually regarding information security and acceptable use of corporate electronic resources. Annual role-based cybersecurity training as well as ongoing participation in a corporate phishing campaign program, is also required of employees and contractors. In addition, as part of the cybersecurity program, we have established controls and procedures to assess the adequacy of controls in place at third-party vendors to protect corporate information, including restricted and confidential restricted information we provide to third-party vendors, their employees, or authorized agents. These third-party vendors are also subject to a background investigation prior to being granted physical or electronic access to the company's private property, or physical access to customer premises on behalf of the company.

As part of the cybersecurity program, we have adopted a cybersecurity incident response plan (the “Plan”) designed to identify, evaluate, respond to, and resolve cybersecurity incidents impacting IT/OT systems. Pursuant to the terms of the Plan, we have established a CSIRT Steering Committee which includes, among others, the Chief Financial Officer, CAO, and the Enterprise Security Director. The CSIRT Steering Committee is responsible for overseeing and implementing the Plan in the event of a cybersecurity
threat or incident and provides updates regarding the status of the response to senior management, including the CEO, who provides updates and reports regarding cybersecurity incidents to the AOC and/or the Board of Directors at regularly scheduled meetings or more frequently, as needed.

In response to an identified cybersecurity incident, or as it deems appropriate, the CSIRT Steering Committee will assemble and oversee a CSIRT, comprised of appropriate personnel and subject matter experts depending on the scope and severity of the incident, relevant or impacted business units and entities, and type of information or systems potentially compromised by the cybersecurity incident. When assembled, the CSIRT is responsible for developing and implementing an overall response strategy to contain, control, and remediate the cybersecurity incident, including securing affected systems and/or information, mitigating harmful effects of the incident, preventing further compromises, and communicating information to affected parties, regulatory agencies and law enforcement, as necessary. The CSIRT may seek assistance from or engage external support providers including legal counsel, outside technology or forensic experts, investigation service providers, and others, as appropriate, to assist in the response to the incident, based on its nature and scope. Pursuant to the Plan and at the direction of the CAO, the Enterprise Security Director will conduct a post-incident remediation analysis and report findings to the CSIRT Steering Committee. The Plan is tested and reviewed at least annually.
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag] true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag] true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Text Block]
We have been subject to attempted cybersecurity attacks from time to time, and will likely continue to be subject to such attempted attacks; however, these prior attacks have not had a material impact on our system or business operations. For information about cybersecurity risks to our business, see Item 1A. Risk Factors and the risk factor titled "Our operations are subject to risks beyond our control, including but not limited to, cybersecurity intrusions, terrorist or other physical attacks, acts of war, or unauthorized access to personally identifiable information."
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]
Our Board of Directors is responsible for general oversight of our risk environment and associated management policies and practices. The Board of Directors has delegated to its AOC the responsibility for oversight of our major risk categories and exposures, including with respect to cybersecurity, and management's processes to monitor and control them. The AOC meets regularly throughout the year and receives and reviews various risk management reports about IT/OT cybersecurity, data security, and physical security risks, and discusses these matters with appropriate management and other personnel. The CEO and CAO regularly report to the AOC and the Board of Directors about cybersecurity matters and risks as well as the adequacy and effectiveness of the cybersecurity risk management program.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block] To foster an enterprise-wide approach to risk management, we have established an ERSC chaired by our CEO and comprised of a cross-functional group of senior leaders from across our organization. The ERSC regularly reviews key risk areas and oversees the development and implementation of effective compliance and risk management practices, including the use of internal and external audits. Our Board of Directors and the AOC receive reports regarding the same. Governance of our cybersecurity risk management program is overseen by the ERSC, along with steering committees for information security, operational technology security, third-party vendor security controls, Sarbanes-Oxley security controls, and North American Electric Reliability Corporation Critical Infrastructure Protection compliance.
Cybersecurity Risk Management Positions or Committees Responsible [Text Block] Our CAO is responsible for enterprise-wide information technology services and cybersecurity system strategy. In this capacity, the CAO oversees the cybersecurity risk management program, which is maintained and implemented by the Enterprise Security Director.The Enterprise Security Director, in collaboration with her team, is responsible for IT/OT cybersecurity, data security, and physical security. The Enterprise Security Director identifies, evaluates, and facilitates mitigation of cyber, data, and physical security risks and reports on cybersecurity matters and risks to the ERSC and the AOC.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block] Our CAO has 26 years of experience at the company, during which time she has held a number of management and leadership positions, including Chief Information Officer, through which she has developed expertise in our IT/OT cybersecurity, data security, and physical security environment and risk profile.Our Enterprise Security Director has over 28 years of experience in IT/OT cybersecurity, data security and physical security, and is a certified information system security professional. She is also a member of numerous state and national cybersecurity organizations.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag] true
v3.25.4
Summary of Significant Accounting Policies (Policies)
12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Nature Of Operations WEC Energy Group serves approximately 1.7 million electric customers and 3.0 million natural gas customers, owns approximately 60% of ATC, and owns majority interests in multiple renewable generating facilities as part of its non-utility energy infrastructure segment.
Consolidation
As used in these notes, the term "financial statements" refers to the consolidated financial statements. This includes the income statements, statements of comprehensive income, balance sheets, statements of cash flows, and statements of equity, unless otherwise noted. On our financial statements, we consolidate our majority-owned subsidiaries, which we control, and VIEs, of which we are the primary beneficiary. We reflect noncontrolling interests for the portion of entities that we do not own as a component of consolidated equity separate from the equity attributable to our shareholders. The noncontrolling interests that we reported as equity on our balance sheet as of December 31, 2025 related to the minority interests held by third parties in the renewable generating facilities that are included in our non-utility energy infrastructure segment.
Segment reporting
Our financial statements include the accounts of WEC Energy Group, a diversified energy holding company, and the accounts of our subsidiaries in the following reportable segments:

Wisconsin segment – Consists of WE, WPS, and WG, which are engaged primarily in the generation of electricity and the distribution of electricity and natural gas in Wisconsin; and UMERC, which generates electricity and distributes electricity and natural gas to customers located in the Upper Peninsula of Michigan.

Illinois segment – Consists of PGL and NSG, which are engaged primarily in the distribution of natural gas in Illinois.

Other states segment – Consists of MERC and MGU, which are engaged primarily in the distribution of natural gas in Minnesota and Michigan, respectively.

Electric transmission segment – Consists of our approximate 60% ownership interest in ATC, a for-profit, electric transmission company regulated by the FERC and certain state regulatory commissions, and our approximate 75% ownership interest in ATC Holdco, which invests in transmission-related projects outside of ATC's traditional footprint.

Non-utility energy infrastructure segment – Consists of We Power, which is principally engaged in the ownership of electric power generating facilities for long-term lease to WE, and Bluewater, which owns underground natural gas storage facilities in Michigan. WECI, which holds our majority interests in multiple renewable generating facilities, is also included in this segment. See Note 2, Acquisitions, for more information on recently acquired WECI renewable generating facilities.

Corporate and other segment – Consists of the WEC Energy Group holding company, the Integrys holding company, the PELLC holding company, Wispark, Wisvest, WECC, and WBS.
Equity method investments Investments in companies not controlled by us, but over which we have significant influence regarding the operating and financial policies of the investee, are accounted for using the equity method. We use the cumulative earnings approach for classifying distributions received in the statements of cash flows. Under the cumulative earnings approach, we compare the distributions received to cumulative equity method earnings since inception. Any distributions received up to the amount of cumulative equity earnings are considered a return on investment and classified in operating activities. Any excess distributions are considered a return of investment and classified in investing activities.
Jointly owned facilities
Our financial statements also reflect our proportionate interests in certain jointly owned utility facilities. See Note 8, Jointly-Owned Utility Facilities, for more information.
Basis of presentation We prepare our financial statements in conformity with GAAP.
Use of estimates We make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from these estimates.
Cash and cash equivalents Cash and cash equivalents include marketable debt securities with an original maturity of three months or less.
Operating revenues The following discussion includes our significant accounting policies related to operating revenues. For additional required disclosures on disaggregation of operating revenues, see Note 4, Operating Revenues.
Revenues from Contracts with Customers

Electric Utility Operating Revenues

Electricity sales to residential and commercial and industrial customers are generally accomplished through requirements contracts, which provide for the delivery of as much electricity as the customer needs. These contracts represent discrete deliveries of electricity and consist of one distinct performance obligation satisfied over time, as the electricity is delivered and consumed by the customer simultaneously. For our Wisconsin residential and commercial and industrial customers and the majority of our Michigan residential and commercial and industrial customers, our performance obligation is bundled to consist of both the sale and the delivery of the electric commodity. In our Michigan service territory, a limited number of residential and commercial and industrial customers can purchase the commodity from a third party. In this case, the delivery of the electricity represents our sole performance obligation.

The transaction price of the performance obligations for residential and commercial and industrial customers is valued using the rates, charges, terms, and conditions of service included in the tariffs of our regulated electric utilities, which have been approved by state regulators. These rates often have a fixed component customer charge and a usage-based variable component charge. We recognize revenue for the fixed component customer charge monthly using a time-based output method. We recognize revenue for the usage-based variable component charge using an output method based on the quantity of electricity delivered each month. Our retail electric rates in Wisconsin include base amounts for fuel and purchased power costs, which also impact our revenues. The electric fuel rules set by the PSCW allow us to defer, for subsequent rate recovery or refund, under- or over-collections of actual fuel and purchased power costs beyond a 2% price variance from the costs included in the rates charged to customers. Our electric utilities monitor the deferral of under-collected costs to ensure that it does not cause them to earn a greater ROE than authorized by the PSCW. In contrast, the rates of our Michigan retail electric customers include recovery of fuel and purchased power costs on a one-for-one basis. In addition, the Wisconsin residential tariffs of WE and WPS include a mechanism for cost recovery or refund of uncollectible expense based on the difference between actual uncollectible write-offs and the amounts recovered in rates.

Wholesale customers who resell power can choose to either bundle capacity and electricity services together under one contract with a supplier or purchase capacity and electricity separately from multiple suppliers. Furthermore, wholesale customers can choose to have our utilities provide generation to match the customer's load, similar to requirements contracts, or they can purchase specified quantities of electricity and capacity. Contracts with wholesale customers that include capacity bundled with the delivery of electricity contain two performance obligations, as capacity and electricity are often transacted separately in the marketplace at the wholesale level. When recognizing revenue associated with these contracts, the transaction price is allocated to each performance obligation based on its relative standalone selling price. Revenue is recognized as control of each individual component is transferred to the customer. Electricity is the primary product sold by our electric utilities and represents a single performance obligation satisfied over time through discrete deliveries to a customer. Revenue from electricity sales is generally recognized as units are produced and delivered to the customer within the production month. Capacity represents the reservation of an electric generating facility and conveys the ability to call on a plant to produce electricity when needed by the customer. The nature of our performance obligation as it relates to capacity is to stand ready to deliver power. This represents a single performance obligation transferred over time, which generally represents a monthly obligation. Accordingly, capacity revenue is recognized on a monthly basis.

The transaction price of the performance obligations for wholesale customers is valued using the rates, charges, terms, and conditions of service, which have been approved by the FERC. These wholesale rates include recovery of fuel and purchased power costs from customers on a one-for-one basis. For the majority of our wholesale customers, the price billed for energy and capacity is a formula-based rate. Formula-based rates initially set a customer's current year rates based on the previous year’s expenses. This is a predetermined formula derived from the utility's costs and a reasonable rate of return. Because these rates are eventually trued up to reflect actual current-year costs, they represent a form of variable consideration in certain circumstances. The variable consideration is estimated and recognized over time as wholesale customers receive and consume the capacity and electricity services.
We are an active participant in the MISO Energy Markets, where we bid our generation into the Day Ahead and Real Time markets and procure electricity for our retail and wholesale customers at prices determined by the MISO Energy Markets. Purchase and sale transactions are recorded using settlement information provided by MISO. These purchase and sale transactions are accounted for on a net hourly position. Net purchases in a single hour are recorded as purchased power in cost of sales, and net sales in a single hour are recorded as resale revenues on our income statements. For resale revenues, our performance obligation is created only when electricity is sold into the MISO Energy Markets.

For all of our customers, consistent with the timing of when we recognize revenue, customer billings generally occur on a monthly basis, with payments typically due in full within 30 days.

Natural Gas Utility Operating Revenues

We recognize natural gas utility operating revenues under requirements contracts with residential, commercial and industrial, and transportation customers served under the tariffs of our regulated utilities. Tariffs provide our customers with the standard terms and conditions, including rates, related to the services offered. Requirements contracts provide for the delivery of as much natural gas as the customer needs. These requirements contracts represent discrete deliveries of natural gas and constitute a single performance obligation satisfied over time. Our performance obligation is both created and satisfied with the transfer of control of natural gas upon delivery to the customer. For most of our customers, natural gas is delivered and consumed by the customer simultaneously. A performance obligation can be bundled to consist of both the sale and the delivery of the natural gas commodity. In certain of our service territories, customers can purchase the commodity from a third party. In this case, the performance obligation only includes the delivery of the natural gas to the customer.

The transaction price of the performance obligations for our natural gas customers is valued using the rates, charges, terms, and conditions of service included in the tariffs of our regulated utilities, which have been approved by state regulators. These rates often have a fixed component customer charge and a usage-based variable component charge. We recognize revenue for the fixed component customer charge monthly using a time-based output method. We recognize revenue for the usage-based variable component charge using an output method based on natural gas delivered each month.

The tariffs of our natural gas utilities include various rate mechanisms that allow them to recover or refund changes in prudently incurred costs from rate case-approved amounts. The rates for all of our natural gas utilities include one-for-one recovery mechanisms for natural gas commodity costs. Under normal circumstances, we defer any difference between actual natural gas costs incurred and costs recovered through rates as a current asset or liability. The deferred balance is returned to or recovered from customers at intervals throughout the year.

In addition, the rates of PGL and NSG, and the residential tariffs of WE, WPS, and WG, include riders or other mechanisms for cost recovery or refund of uncollectible expense based on the difference between actual uncollectible write-offs and the amounts recovered in rates. The rates of PGL and NSG include riders for cost recovery of both environmental cleanup costs and energy conservation and management program costs. Finally, through the end of 2023 and effective again starting January 1, 2025, the rates of MGU include a rider to recover costs incurred to replace or modify natural gas facilities.

Consistent with the timing of when we recognize revenue, customer billings generally occur on a monthly basis, with payments typically due in full within 30 days.

Other Natural Gas Operating Revenues

We have other natural gas operating revenues from Bluewater, which is in our non-utility energy infrastructure segment. Bluewater owns underground natural gas storage facilities in southeastern Michigan and provides natural gas storage and hub services to customers. Bluewater has entered into long-term service agreements for natural gas storage services with WE, WPS, and WG, and also provides limited service to unaffiliated customers. We recognize revenues using a time-based output method through a monthly fixed service fee. Typical storage contract rates consist of firm storage reservation charges and firm injection and withdrawal charges. All amounts associated with the service agreements with WE, WPS, and WG have been eliminated at the consolidated level.

Other Non-Utility Operating Revenues

Wind and solar generation revenues from WECI's ownership interests in renewable generation facilities continued to grow in 2025. See Note 2, Acquisitions, for more information on recent acquisitions. Most of these renewable generation facilities have offtake agreements with unaffiliated third parties for all of the energy to be produced by the facility, some of which are bundled with
capacity and RECs. We consider bundled energy, capacity, and RECs within these offtake agreements to be distinct performance obligations as each are often transacted separately in the marketplace.

When recognizing revenue associated with these contracts, the transaction price is allocated to each performance obligation based on its relative standalone selling price. Revenue is recognized as control of each individual component is transferred to the customer. Revenue from the sale of this renewable energy is generally recognized as units are produced and delivered to the customer within the production month. Capacity represents the reservation of the renewable generation facility and conveys the ability to call on the renewable generation facility to produce electricity when needed by the customer. The nature of our performance obligation as it relates to capacity is to stand ready to deliver power. This represents a single performance obligation transferred over time, which generally represents a monthly obligation. Accordingly, capacity revenue is recognized on a monthly basis. The performance obligation for RECs is recognized at a point-in-time; however, the timing of revenue recognition is the same, as the generation of renewable energy and the recognition of REC revenues generally occur concurrently.

Non-utility operating revenues are also derived from servicing appliances for customers at MERC. These contracts customarily have a duration of one year or less and consist of a single performance obligation satisfied over time. We use a time-based output method to recognize revenues monthly for the service fee.

Consistent with the timing of when we recognize revenue, customer billings for the renewable generation and servicing revenues generally occur on a monthly basis, with payments typically due in full within 30 days.

As part of the construction of the We Power electric generating units, we capitalized interest during construction, which is included in property, plant, and equipment. As allowed by the PSCW, we collected these carrying costs from WE's utility customers during construction. The equity portion of these carrying costs was recorded as a contract liability, which is presented as deferred revenue, net on our balance sheets. We continually amortize the deferred carrying costs to revenues over the related lease term that We Power has with WE. During 2025, 2024, and 2023, we recorded $24.6 million, $24.3 million, and $23.5 million, respectively, of revenues related to these deferred carrying costs.

Other Operating Revenues

Bespoke Resources Current Return

We recognize revenues monthly associated with carrying costs, including financing costs, during the construction period of bespoke resources assigned to WE's very large utility customers under payment and cancellation agreements. These amounts are not considered revenues from contracts with customers as electricity is not yet being provided by WE. Consistent with the timing of when we recognize revenue, customer billings for the bespoke resources that are subject to current return (as opposed to AFUDC) occur on a monthly basis, with payments typically due in full within 45 days.

Alternative Revenues

Alternative revenues are created from programs authorized by regulators that allow our utilities to record additional revenues by adjusting rates in the future, usually as a surcharge applied to future billings, in response to past activities or completed events. Alternative revenue programs allow compensation for the effects of weather abnormalities, other external factors, or demand side management initiatives. Alternative revenue programs can also provide incentive awards if the utility achieves certain objectives and in other limited circumstances. We record alternative revenues when the regulator-specified conditions for recognition have been met. We reverse these alternative revenues as the customer is billed, at which time this revenue is presented as revenues from contracts with customers.

Below is a summary of the alternative revenue programs at our utilities:

The rates of PGL, NSG, and MERC include decoupling mechanisms. These mechanisms differ by state and allow the utilities to recover or refund the differences between actual and authorized margins for certain customer classes.
MERC’s rates include a conservation improvement program rider, which includes a financial incentive for meeting energy savings goals.
WE and WPS provide wholesale electric service to customers under market-based rates and FERC formula rates. The customer is charged a base rate each year based upon a formula using prior year actual costs and customer demand. A true-up is calculated based on the difference between the amount billed to customers for the demand component of their rates and what the actual
cost of service was for the year. The true-up can result in an amount that we will recover from or refund to the customer. We consider the true-up portion of the wholesale electric revenues to be alternative revenues.
Credit losses The following discussion includes our significant accounting policies related to credit losses. For additional required disclosures on credit losses, see Note 5, Credit Losses.
Our exposure to credit losses is related to our accounts receivable and unbilled revenue balances, which are primarily generated from the sale of electricity and natural gas by our regulated utility operations. Credit losses associated with our utility operations are analyzed at the reportable segment level as we believe contract terms, political and economic risks, and the regulatory environment are similar at this level as our reportable segments are generally based on the geographic location of the underlying utility operations.

We have an accounts receivable and unbilled revenue balance associated with our non-utility energy infrastructure segment, related to the sale of electricity from our majority-owned renewable generating facilities through agreements with several large high credit quality counterparties.

We evaluate the collectability of our accounts receivable and unbilled revenue balances considering a combination of factors. For some of our larger customers and also in circumstances where we become aware of a specific customer's inability to meet its financial obligations to us, we record a specific allowance for credit losses against amounts due in order to reduce the net recognized receivable to the amount we reasonably believe will be collected. For all other customers, we use the accounts receivable aging method to calculate an allowance for credit losses. Using this method, we classify accounts receivable into different aging buckets and calculate a reserve percentage for each aging bucket based upon historical loss rates. The calculated reserve percentages are updated on at least an annual basis, in order to ensure recent macroeconomic, political, and regulatory trends are captured in the calculation, to the extent possible. Risks identified that we do not believe are reflected in the calculated reserve percentages, are assessed on a quarterly basis to determine whether further adjustments are required.
We monitor our ongoing credit exposure through active review of counterparty accounts receivable balances against contract terms and due dates. Our activities include timely account reconciliation, dispute resolution and payment confirmation. To the extent possible, we work with customers with past due balances to negotiate payment plans, but will disconnect customers for non-payment as allowed by our regulators, if necessary, and employ collection agencies and legal counsel to pursue recovery of defaulted receivables. For our larger customers, detailed credit review procedures may be performed in advance of any sales being made. We sometimes require letters of credit, parental guarantees, prepayments or other forms of credit assurance from our larger customers, including VLCs, to mitigate credit risk.
Materials, supplies and inventories Our inventories as of December 31 consisted of:
(in millions)20252024
Materials and supplies$416.4 $412.5 
Natural gas in storage292.5 300.2 
Fossil fuel94.5 100.5 
Total$803.4 $813.2 

PGL and NSG price natural gas storage injections at the calendar year average of the costs of natural gas supply purchased. Withdrawals from storage are priced on the LIFO cost method. Inventories stated on a LIFO basis represented approximately 17% and 18% of total inventories at December 31, 2025 and 2024, respectively. The estimated replacement cost of natural gas in inventory at December 31, 2025 and 2024, exceeded the LIFO cost by $94.9 million and $77.9 million, respectively. In calculating these replacement amounts, PGL and NSG used a Chicago city-gate natural gas price per Dth of $3.36 at December 31, 2025, and $3.10 at December 31, 2024.

Substantially all other materials and supplies, natural gas in storage, and fossil fuel inventories are recorded using the weighted-average cost method of accounting.
Regulatory assets and liabilities The economic effects of regulation can result in regulated companies recording costs and revenues that are allowed in the ratemaking process in a period different from the period they would have been recognized by a nonregulated company. When this occurs, regulatory assets and liabilities are recorded on the balance sheet. Regulatory assets represent deferred costs probable of recovery from customers that would have otherwise been charged to expense. Regulatory
liabilities represent amounts that are expected to be refunded to customers in future rates or future costs already collected from customers in rates.

The recovery or refund of regulatory assets and liabilities is based on specific periods determined by our regulators or occurs over the normal operating period of the related assets and liabilities. If a previously recorded regulatory asset is no longer probable of recovery, the regulatory asset is reduced to the amount considered probable of recovery, and the reduction is charged to expense in the current period. See Note 6, Regulatory Assets and Liabilities, for more information.
Property, plant, and equipment We record property, plant, and equipment at cost. Cost includes material, labor, overhead, and both debt and equity components of AFUDC. Additions to and significant replacements of property are charged to property, plant, and equipment at cost; minor items are charged to other operation and maintenance expense. The cost of depreciable utility property less salvage value is charged to accumulated depreciation when property is retired.
We record straight-line depreciation expense over the estimated useful life of utility property using depreciation rates approved by the applicable regulators. Annual utility composite depreciation rates are shown below:
Annual Utility Composite Depreciation Rates 202520242023
WE3.07%3.03%3.03%
WPS3.01%2.92%2.93%
WG2.45%2.61%2.61%
PGL3.34%3.36%3.13%
NSG2.49%2.49%2.46%
MERC2.62%2.60%2.60%
MGU2.87%2.87%2.73%
UMERC3.20%3.01%2.97%

We depreciate our We Power assets over the estimated useful life of the various property components. The components have useful lives of between 10 to 45 years for PWGS 1 and PWGS 2 and 10 to 55 years for ER 1 and ER 2.

We depreciate our WECI assets over the estimated useful life of the property, with wind and solar generating facilities being depreciated over 30 and 35 years, respectively.

We capitalize certain costs related to software developed or obtained for internal use and record these costs to amortization expense over the estimated useful life of the related software, which ranges from 3 to 15 years. If software is retired prior to being fully amortized, the difference is recorded as a loss on the income statement.

Third parties reimburse the utilities for all or a portion of expenditures for certain capital projects. Such contributions in aid of construction costs are recorded as a reduction to property, plant, and equipment.

See Note 7, Property, Plant, and Equipment, for more information.
AFUDC AFUDC is included in utility plant accounts and represents the cost of borrowed funds (AFUDC-Debt) used during plant construction, and a return on shareholders' capital (AFUDC-Equity) used for construction purposes. AFUDC-Debt is recorded as a reduction of interest expense, and AFUDC-Equity is recorded in other income, net.
The majority of AFUDC is recorded at WE, WPS, WG, UMERC, and WBS. Approximately 50% of WE's, WPS's, WG's, UMERC's, and WBS's retail jurisdictional CWIP expenditures are subject to the AFUDC calculation. AFUDC rates are determined by their respective state commissions, each with specific requirements. Average AFUDC rates are shown below:
2025
Average AFUDC Retail RateAverage AFUDC Wholesale Rate
WE8.65%7.51%
WPS7.82%6.62%
WG8.54%N/A
UMERC6.40%N/A
WBS7.82%N/A

Our regulated utilities and WBS recorded the following AFUDC for the years ended December 31:
(in millions)202520242023
AFUDC-Debt
WE$29.8 $14.6 $13.0 
WPS4.7 3.6 2.9 
UMERC3.4 0.4 — 
WG0.5 0.5 3.4 
WBS0.2 0.1 0.1 
Other0.4 0.2 0.1 
Total AFUDC-Debt$39.0 $19.4 $19.5 
AFUDC-Equity
WE$78.9 $46.0 $41.0 
WPS12.2 9.2 7.6 
UMERC6.3 1.0 — 
WG1.2 2.9 9.8 
WBS0.5 0.3 0.4 
Other0.7 0.4 0.3 
Total AFUDC-Equity$99.8 $59.8 $59.1 

See Note 16, Income Taxes, for more information on how AFUDC-Equity is treated for tax purposes and the related impact on total WEC Energy Group income tax expense.
Cloud computing hosting arrangements that are service contracts We have entered into several cloud computing arrangements that are hosted service contracts as part of projects related to the continuous transformation of technology. These projects include, among other things, a centralized repository for data to improve analytics, reporting, work and asset management, targeted enterprise resource planning systems, human resources management, employee scheduling, geospatial information, training, information technology service management, and customer contact systems. We present prepaid hosting fees that are service contracts in either prepayments or other long-term assets on our balance sheets and amortize them as the hosting services are received. Amortization expense, as well as the fees associated with the hosting arrangements, is recorded in other operation and maintenance expense on our income statements.
At December 31, 2025 and 2024, we had $27.0 million and $17.0 million, respectively, of capitalized implementation costs related to cloud computing arrangements that are hosted service contracts. We amortize the implementation costs on a straight-line basis over the cloud computing service arrangement term once the component of the hosted service is ready for its intended use. Accumulated amortization at December 31, 2025 and 2024, was $5.8 million and $4.1 million, respectively. Amortization expense for the years ended December 31, 2025, 2024, and 2023 was not significant. The presentation of the implementation costs, along with the related accumulated amortization, follows the prepaid hosting fees.
Impairment of goodwill and other intangible assets Goodwill and other intangible assets with indefinite lives are subject to an annual impairment test. Interim impairment tests are performed when impairment indicators are present. During the third quarter of each year, we perform an annual impairment test for all of our reporting units that carried a goodwill balance. The carrying amount of the reporting unit's goodwill is considered not recoverable if the carrying amount of the reporting unit's net assets exceeds the reporting unit's fair
value. An impairment loss is recorded as the excess of the carrying amount of the goodwill over its fair value. For our indefinite-lived intangible assets, an impairment loss is recognized when the carrying amount of an asset is not recoverable and exceeds its fair value. An impairment loss is measured as the excess of the carrying amount of the intangible asset over its fair value. No impairment losses were recorded for our indefinite-lived intangible assets during the years ended December 31, 2025, 2024, and 2023. See Note 10, Goodwill and Intangibles, for more information.
Impairment of long-lived assets
We periodically assess the recoverability of certain long-lived assets when factors indicate the carrying value of such assets may be impaired or such assets are planned to be sold. Long-lived assets that would be subject to an impairment assessment generally include any assets within regulated operations that may not be fully recovered from our customers as a result of regulatory decisions that will be made in the future, as well as assets within nonregulated operations that are proposed to be sold or are currently generating operating losses. An impairment loss is recognized when the carrying amount of an asset is not recoverable and exceeds its fair value. The carrying amount of an asset is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. An impairment loss is measured as the excess of the carrying amount of the asset over its fair value.

We also periodically assess the recoverability of our non-utility long-lived assets, which includes reviewing current activities, changes in the conditions of our renewable generating facilities, and market conditions in which they operate to determine the existence of any indicators requiring an impairment analysis. Indicators of potential impairment for a non-utility long-lived asset group, generally an individual renewable generation project, include adverse changes in the financial condition of a customer to our offtake agreements, a significant decline in the forecasted operating revenues and earnings of our renewable generation projects, and deterioration in the performance of our renewable generation projects.

We assess the likelihood of a disallowance of part of the cost of recently completed plant by considering factors such as applicable regulatory environment changes, our own recent rate orders, as well as recent rate orders of other regulated entities in similar jurisdictions. When it becomes probable that part of the cost of recently completed plant will be disallowed for rate-making purposes, we assess whether a reasonable estimate of the amount of the disallowance can be made. The estimated amount of the probable disallowance will then be deducted from the reported cost of the plant and recognized as an impairment loss.

When it becomes probable that a generating unit will be retired before the end of its useful life, we assess whether the generating unit meets the criteria for abandonment accounting. Generating units that are considered probable of abandonment are expected to cease operations in the near term, significantly before the end of their original estimated useful lives. If a generating unit meets the applicable criteria to be considered probable of abandonment, and the unit has been abandoned, we assess the likelihood of recovery of the remaining net book value of that generating unit at the end of each reporting period. If it becomes probable that regulators will disallow full recovery as well as a return on the remaining net book value of a generating unit that is either abandoned or probable of being abandoned, an impairment loss may be required. An impairment loss would be recorded if the remaining net book value of the generating unit is greater than the present value of the amount expected to be recovered from ratepayers, using an incremental borrowing rate. See Note 6, Regulatory Assets and Liabilities, and Note 7, Property, Plant, and Equipment, for more information.
We recorded the following impairment losses on our income statements in the following segments during the years ended December 31:
(in millions)202520242023
Illinois$130.0 
(1)
$12.1 
(2)
$178.9 
(3)
Non-utility energy infrastructure (4)
15.9 — — 
Total impairment losses$145.9 $12.1 $178.9 

(1)    Represents a probable disallowance of certain capital costs at PGL under the QIP rider. See Note 26, Regulatory Environment, for more information.
(2)    Represents a disallowance of certain previously incurred capital costs at PGL resulting from an ICC order received in August 2024 related to the 2016 annual prudency review of the QIP rider. See Note 26, Regulatory Environment, for more information.

(3)    Represents a disallowance of certain previously incurred capital costs resulting from PGL's and NSG's November 2023 rate orders from the ICC. See Note 26, Regulatory Environment, for more information.
(4)    Represents impairment losses related to storm damage at certain of WECI's renewable generation facilities.
Impairment of equity method investments
We periodically assess the recoverability of equity method investments when factors indicate the carrying amount of such assets may be impaired. Equity method investments are assessed for impairment by comparing the fair values of these investments to their carrying amounts if a fair value assessment was completed or by reviewing for the presence of impairment indicators. If an impairment exists, and it is determined to be other-than-temporary, an impairment loss is recognized equal to the amount by which the carrying amount exceeds the investment's fair value.
Asset retirement obligations We recognize, at fair value, legal obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development, and normal operation of the assets. An ARO liability is recorded, when incurred, for these obligations as long as the fair value can be reasonably estimated, even if the timing or method of settling the obligation is unknown. The associated retirement costs are capitalized as part of the related long-lived asset and are depreciated over the useful life of the asset. The ARO liabilities are accreted each period using the credit-adjusted risk-free interest rates associated with the expected settlement dates of the AROs. These rates are determined when the obligations are incurred. Subsequent changes resulting from revisions to the timing or the amount of the original estimate of undiscounted cash flows are recognized as an increase or a decrease to the carrying amount of the liability and the associated capitalized retirement costs. For our regulated entities, we recognize regulatory assets or liabilities for the timing differences between when we recover an ARO in rates and when we recognize the associated retirement costs. See Note 9, Asset Retirement Obligations, for more information.
Finite-lived intangible assets and liabilities Our finite-lived intangible asset and liabilities include revenue contracts, consisting of PPAs and a proxy revenue swap, in addition to interconnection agreements, which resulted from the acquisitions of renewable generation facilities by WECI in our non-utility energy infrastructure segment. Intangible asset and liabilities are amortized on a straight-line basis over their estimated useful lives, which is the term of the related agreement. Amortization of the revenue intangible asset and liabilities are recorded within operating revenues in the income statements. Amortization of the interconnection agreement intangible liabilities is recorded within other operation and maintenance in the income statements. The straight-line method of amortization is used because it best reflects the pattern in which the economic benefits of the intangibles are consumed or otherwise used. The amounts and useful lives assigned to the intangible asset and liabilities assumed impact the amount and timing of future amortization. See Note 10, Goodwill and Intangibles, for more information
Stock-based compensation In accordance with the Omnibus Stock Incentive Plan, we provide long-term incentives through our equity interests to our non-employee directors, officers, and other key employees. The plan provides for the granting of stock options, restricted stock, performance shares, and other stock-based awards. Awards may be paid in common stock, cash, or a combination thereof. In addition to those shares of common stock that were subject to awards outstanding as of May 6, 2021, when the plan was last approved by shareholders, 9.0 million shares were reserved for issuance under the plan.
We recognize stock-based compensation expense on a straight-line basis over the requisite service period. Awards classified as equity awards are measured based on their grant-date fair value. Awards classified as liability awards are recorded at fair value each reporting period. We account for forfeitures as they occur.

Stock Options

We grant non-qualified stock options that generally vest on a cliff-basis after three years. The exercise price of a stock option under the plan cannot be less than 100% of our common stock's fair market value on the grant date. Historically, all stock options have been granted with an exercise price equal to the fair market value of our common stock on the date of the grant. Options vest immediately upon retirement, death, or disability; however, they may not be exercised within six months of the grant date except in connection with certain termination of employment events following a change in control. Options expire no later than 10 years from the date of the grant.
Our stock options are classified as equity awards. The fair value of our stock options was calculated using a binomial option-pricing model. The following table shows the estimated weighted-average fair value per stock option granted along with the weighted-average assumptions used in the valuation models:
202520242023
Stock options granted231,024 294,990 257,780 
Estimated weighted-average fair value per stock option$18.23 $16.19 $19.58 
Assumptions used to value the options:
Risk-free interest rate
4.2% – 4.6%
3.9% – 5.4%
3.8% – 4.8%
Dividend yield4.1 %3.8 %3.2 %
Expected volatility22.0 %22.0 %22.0 %
Expected life (years)8.38.48.3

The risk-free interest rate was based on the United States Treasury interest rate with a term consistent with the expected life of the stock options. The dividend yield was based on our dividend rate at the time of the grant and historical stock prices. Expected volatility and expected life assumptions were based on our historical experience.

Restricted Shares

Restricted shares granted to employees generally have a vesting period of three years with one-third of the award vesting on each anniversary of the grant date. Restricted shares granted to non-employee directors fully vest after one year.

Our restricted shares are classified as equity awards.

Performance Units

Officers and other key employees are granted performance units under the WEC Energy Group Performance Unit Plan. All grants of performance units are settled in cash and are accounted for as liability awards accordingly. Performance units accrue forfeitable dividend equivalents in the form of additional performance units. The fair value of the performance units reflects our estimate of the final expected value of the awards, which is based on our stock price and performance achievement under the terms of the award. Stock-based compensation costs are generally recorded over the performance period, which is three years.

Pursuant to the terms of the WEC Energy Group Performance Unit Plan, the Compensation Committee selected multiple performance measures that will be weighted to determine the ultimate payout of the performance unit awards. The ultimate number of units that will be paid out will be based on our total shareholder return compared to the total shareholder return of a peer group of companies over three years (55%), and our performance against the weighted average authorized ROE of all of our utility subsidiaries (45%). In addition, the Compensation Committee selected the level of our stock price to earnings ratio compared to our peer companies as a performance measure that can increase the payout by up to 25%. In no event can the performance unit payout be greater than 200% of the target award.

See Note 11, Common Equity, for more information on our stock-based compensation plans.
Stock-based compensation - forfeitures We account for forfeitures as they occur.
Earnings per share We compute basic EPS by dividing our net income attributed to common shareholders by the weighted-average number of common shares outstanding during the period. Diluted EPS is computed in a similar manner, but includes the exercise, settlement, and/or conversion of all potentially dilutive securities. Our potentially dilutive securities include stock options, forward equity sales contracts, and shares issuable upon the conversion of our convertible debt instruments.
The dilutive impacts from our in-the-money stock options and forward equity sales contract are calculated using the treasury stock method. The calculation of diluted EPS for the year ended December 31, 2025 excluded 58,533 shares issuable under our forward equity sales contract as their effect was anti-dilutive. The calculation of diluted EPS for the years ended December 31, 2024 and 2023 excluded 66,870 and 1,716,286 stock options, respectively, that had an anti-dilutive effect. No stock options had an anti-dilutive effect for the year ended December 31, 2025, and we did not have any forward equity sales contracts prior to 2025.
Potentially dilutive common shares issuable upon conversion of our convertible debt instruments are calculated using the if-converted method. For the year ended December 31, 2025, there were no shares of our common stock related to the potential conversion of the 2028 Notes (issued in June 2025) included in our diluted EPS calculation as the impact was anti-dilutive. For the year ended December 31, 2024, there were no shares of our common stock related to the potential conversion of the 2027 Notes and 2029 Notes (both issued in 2024) included in our diluted EPS calculation as the impact was anti-dilutive.

See Note 11, Common Equity, for more information on the computation of our basic and diluted EPS.
Leases We recognize a right of use asset and lease liability for operating and finance leases with a term of greater than one year. As a policy election, we account for each lease component separately from the nonlease components of a contract.
We are currently party to several easement agreements that allow us access to land we do not own for the purpose of constructing and maintaining certain electric power and natural gas equipment. The majority of payments we make related to easements relate to our renewable generating facilities. We have not classified our easements as leases because we view the entire parcel of land specified in our easement agreements to be the identified asset, not just that portion of the parcel that contains our easement. As such, we have concluded that we do not control the use of an identified asset related to our easement agreements, nor do we obtain substantially all of the economic benefits associated with these shared-use assets.

See Note 15, Leases, for more information.
Income taxes In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. The amendments require additional disclosures, primarily related to income taxes paid and the rate reconciliation table. The amendments require disclosures on specific categories in the rate reconciliation table, as well as additional information for reconciling items that meet a quantitative threshold. For income taxes paid, additional disclosures are required to disaggregate federal, state, and foreign income taxes paid, with additional disclosures for income taxes paid that meet a quantitative threshold. We adopted ASU No. 2023-09 on January 1, 2025, on a retroactive basis, with the required disclosures first included in our 2025 Annual Report on Form 10-K.
We follow the liability method in accounting for income taxes. Accounting guidance for income taxes requires the recording of deferred assets and liabilities to recognize the expected future tax consequences of events that have been reflected in our financial statements or tax returns and the adjustment of deferred tax balances to reflect tax rate changes. We are required to assess the likelihood that our deferred tax assets would expire before being realized. If we conclude that certain deferred tax assets are likely to expire before being realized, a valuation allowance would be established against those assets. GAAP requires that, if we conclude in a future period that it is more likely than not that some or all of the deferred tax assets would be realized before expiration, we reverse the related valuation allowance in that period. Any change to the allowance, as a result of a change in judgment about the realization of deferred tax assets, is reported in income tax expense.

ITCs are deferred and amortized over the life of the assets. PTCs are recognized in the period in which such credits are generated. The amount of the credit is based upon power production from our qualifying generation facilities. We file a consolidated federal income tax return. Accordingly, we allocate federal current tax expense, benefits, and credits to our subsidiaries based on their separate tax computations and our ability to monetize all credits on our consolidated federal return.

We recognize interest and penalties accrued, related to unrecognized tax benefits, in income tax expense in our income statements.

The IRA contains a tax credit transferability provision that allows us to sell PTCs and ITCs produced after December 31, 2022, to third parties. Under this transferability provision, we entered into agreements to sell the majority of the PTCs and ITCs we generated in 2023, 2024, and 2025 to third parties. See Note 16, Income Taxes, for more information on the PTCs we sold. We have also entered into an agreement to sell the majority of PTCs that we expect to generate in 2026 to third parties. We elect to account for tax credits transferred under the scope of ASC 740. We include the discount from the sale of tax credits as a component of income tax expense. We also include any expected proceeds from the sale of tax credits in the evaluation of the realizability of deferred tax assets related to PTCs and ITCs. The sale of tax credits is presented in the operating activities section of the statements of cash flows consistent with the presentation of cash taxes paid.

In April 2023, the IRS issued Revenue Procedure 2023-15, which provides a safe harbor method of accounting that taxpayers may use to determine whether expenses to repair, maintain, replace, or improve natural gas transmission and distribution property must be capitalized for tax purposes. We adopted the safe harbor method of accounting for certain of our utilities on our 2023 tax return
and adopted the safe harbor method of accounting for our remaining utilities on our 2024 tax return, which increased our deferred tax liabilities.

See Note 16, Income Taxes, for more information.
Fair value measurements Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price).
Fair value accounting rules provide a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The three levels of the fair value hierarchy are defined as follows:

Level 1 – Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis.

Level 2 – Pricing inputs are observable, either directly or indirectly, but are not quoted prices included within Level 1. Level 2 includes those financial instruments that are valued using external inputs within models or other valuation methods.

Level 3 – Pricing inputs include significant inputs that are generally less observable from objective sources. These inputs may be used with internally developed methods that result in management's best estimate of fair value. Level 3 instruments include those that may be more structured or otherwise tailored to customers' needs.

Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. We use a mid-market pricing convention (the mid-point price between bid and ask prices) as a practical measure for valuing certain derivative assets and liabilities. We primarily use a market approach for recurring fair value measurements and attempt to use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs.

When possible, we base the valuations of our assets and liabilities on quoted prices for identical assets and liabilities in active markets. These valuations are classified in Level 1. The valuations of certain contracts not classified as Level 1 may be based on quoted market prices received from counterparties and/or observable inputs for similar instruments. Transactions valued using these inputs are classified in Level 2. Certain derivatives, such as FTRs and TCRs, are categorized in Level 3 due to the significance of unobservable or internally-developed inputs. FTRs and TCRs are valued using auction prices from the applicable RTO.

See Note 17, Fair Value Measurements, for more information.
Derivative instruments We use derivatives as part of our risk management program to manage the risks associated with the price volatility of interest rates, purchased power, generation, and natural gas costs for the benefit of our customers and shareholders. Our approach is non-speculative and designed to mitigate risk. Regulated hedging programs are approved by our state regulators.
We record derivative instruments on our balance sheets as assets or liabilities measured at fair value unless they qualify for the normal purchases and sales exception, and are so designated. We continually assess our contracts designated as normal and will discontinue the treatment of these contracts as normal if the required criteria are no longer met. Changes in the derivative's fair value are recognized currently in earnings unless specific hedge accounting criteria are met or we receive regulatory treatment for the derivative. For most energy-related physical and financial contracts in our regulated operations that qualify as derivatives, our regulators allow the effects of fair value accounting to be offset to regulatory assets and liabilities.

We classify derivative assets and liabilities as current or long-term on our balance sheets based on the maturities of the underlying contracts. Cash flows from derivative activities are presented in the same category as the item being hedged within operating activities on our statements of cash flows.

Derivative accounting rules provide the option to present certain asset and liability derivative positions net on the balance sheets and to net the related cash collateral against these net derivative positions. We elected not to net these items. On our balance sheets, cash collateral provided to others is reflected in other current assets, and cash collateral received is reflected in other current liabilities. See Note 18, Derivative Instruments, for more information.
Guarantees We follow the guidance of the Guarantees Topic of the FASB ASC, which requires, under certain circumstances, that the guarantor recognize a liability for the fair value of the obligation undertaken in issuing the guarantee at its inception. See Note 19, Guarantees, for more information.
Employee benefits The costs of pension and OPEB plans are expensed over the periods during which employees render service. These costs are distributed among our subsidiaries based on current employment status and actuarial calculations, as applicable. Our regulators allow recovery in rates for the utilities' net periodic benefit cost calculated under GAAP. See Note 20, Employee Benefits, for more information.
Customer deposits and credit balances When utility customers apply for new service, they may be required to provide a deposit for the service. Customer deposits are recorded within other current liabilities on our balance sheets.
Utility customers can elect to be on a budget plan. Under this type of plan, a monthly installment amount is calculated based on estimated annual usage. During the year, the monthly installment amount is reviewed by comparing it to actual usage. If necessary, an adjustment is made to the monthly amount. Annually, the budget plan is reconciled to actual annual usage. Payments in excess of actual customer usage are recorded within other current liabilities on our balance sheets.
Environmental remediation costs We are subject to federal and state environmental laws and regulations that in the future may require us to pay for environmental remediation at sites where we have been, or may be, identified as a potentially responsible party. Loss contingencies may exist for the remediation of hazardous substances at various potential sites, including CCR landfills and manufactured gas plant sites. See Note 9, Asset Retirement Obligations, for more information regarding CCR landfills and Note 24, Commitments and Contingencies, for more information regarding manufactured gas plant sites.
We record environmental remediation liabilities when site assessments indicate remediation is probable, and we can reasonably estimate the loss or a range of losses. The estimate includes both our share of the liability and any additional amounts that will not be paid by other potentially responsible parties or the government. When possible, we estimate costs using site-specific information but also consider historical experience for costs incurred at similar sites. Remediation efforts for a particular site generally extend over a period of several years. During this period, the laws governing the remediation process may change, as well as site conditions, potentially affecting the cost of remediation.

Our utilities have received approval to defer certain environmental remediation costs, as well as estimated future costs, through a regulatory asset. The recovery of deferred costs is subject to the applicable state regulatory commission's approval.

We review our estimated costs of remediation annually for our manufactured gas plant sites and CCR landfills. We adjust the liabilities and related regulatory assets, as appropriate, to reflect the new cost estimates. Any material changes in cost estimates are adjusted throughout the year.
Customer concentration of credit risk The geographic concentration of our customers did not contribute significantly to our overall exposure to credit risk. We periodically review customers' credit ratings, financial statements, and historical payment performance and require them to provide collateral or other security as needed. Although we have a comprehensive credit evaluation process and contractual protections, it is possible that one or more counterparties could fail to perform their obligations, and we could recognize financial losses as a result. Credit risk exposure at WE, WPS, WG, PGL, and NSG is mitigated by their recovery mechanisms for uncollectible expense discussed in Note 1(d), Operating Revenues. There were no customers that accounted for more than 10% of our revenues for the year ended December 31, 2025.As a result, for the majority of our utility companies, we did not have any significant concentrations of credit risk at December 31, 2025. However, WE has contracts with a small number of customers to provide power to large-scale data centers to support AI and other technology capabilities. This concentration of business with a small number of customers in an industry based on emerging technologies presents several risks. WE is incurring significant costs to construct bespoke resources to serve these customers. Although WE requires these customers to enter into payment and cancellation agreements, WE may still experience significant losses or delayed recovery of these costs. Changes in industry practice or advances in these technologies could reduce the demand for electricity to power data centers, which would reduce our forecasted revenues. Significant capital spend to build out required infrastructure or a downturn in business could weaken their financial condition, liquidity and/or creditworthiness, including their ability to satisfy their reimbursement obligations to us.
v3.25.4
Summary of Significant Accounting Policies (Tables)
12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Schedule of inventory Our inventories as of December 31 consisted of:
(in millions)20252024
Materials and supplies$416.4 $412.5 
Natural gas in storage292.5 300.2 
Fossil fuel94.5 100.5 
Total$803.4 $813.2 
Schedule of annual utility composite depreciation rates Annual utility composite depreciation rates are shown below:
Annual Utility Composite Depreciation Rates 202520242023
WE3.07%3.03%3.03%
WPS3.01%2.92%2.93%
WG2.45%2.61%2.61%
PGL3.34%3.36%3.13%
NSG2.49%2.49%2.46%
MERC2.62%2.60%2.60%
MGU2.87%2.87%2.73%
UMERC3.20%3.01%2.97%
Schedule of AFUDC rates and amounts Average AFUDC rates are shown below:
2025
Average AFUDC Retail RateAverage AFUDC Wholesale Rate
WE8.65%7.51%
WPS7.82%6.62%
WG8.54%N/A
UMERC6.40%N/A
WBS7.82%N/A

Our regulated utilities and WBS recorded the following AFUDC for the years ended December 31:
(in millions)202520242023
AFUDC-Debt
WE$29.8 $14.6 $13.0 
WPS4.7 3.6 2.9 
UMERC3.4 0.4 — 
WG0.5 0.5 3.4 
WBS0.2 0.1 0.1 
Other0.4 0.2 0.1 
Total AFUDC-Debt$39.0 $19.4 $19.5 
AFUDC-Equity
WE$78.9 $46.0 $41.0 
WPS12.2 9.2 7.6 
UMERC6.3 1.0 — 
WG1.2 2.9 9.8 
WBS0.5 0.3 0.4 
Other0.7 0.4 0.3 
Total AFUDC-Equity$99.8 $59.8 $59.1 
Schedule of impairment losses
We recorded the following impairment losses on our income statements in the following segments during the years ended December 31:
(in millions)202520242023
Illinois$130.0 
(1)
$12.1 
(2)
$178.9 
(3)
Non-utility energy infrastructure (4)
15.9 — — 
Total impairment losses$145.9 $12.1 $178.9 

(1)    Represents a probable disallowance of certain capital costs at PGL under the QIP rider. See Note 26, Regulatory Environment, for more information.
(2)    Represents a disallowance of certain previously incurred capital costs at PGL resulting from an ICC order received in August 2024 related to the 2016 annual prudency review of the QIP rider. See Note 26, Regulatory Environment, for more information.

(3)    Represents a disallowance of certain previously incurred capital costs resulting from PGL's and NSG's November 2023 rate orders from the ICC. See Note 26, Regulatory Environment, for more information.
(4)    Represents impairment losses related to storm damage at certain of WECI's renewable generation facilities.
Schedule of assumptions used to estimate the fair value of stock options granted The following table shows the estimated weighted-average fair value per stock option granted along with the weighted-average assumptions used in the valuation models:
202520242023
Stock options granted231,024 294,990 257,780 
Estimated weighted-average fair value per stock option$18.23 $16.19 $19.58 
Assumptions used to value the options:
Risk-free interest rate
4.2% – 4.6%
3.9% – 5.4%
3.8% – 4.8%
Dividend yield4.1 %3.8 %3.2 %
Expected volatility22.0 %22.0 %22.0 %
Expected life (years)8.38.48.3
v3.25.4
Acquisitions (Tables) - WECI
12 Months Ended
Dec. 31, 2025
Hardin III  
Asset Acquisition  
Allocation of purchase price
The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at the date of the acquisition.
(in millions)
Net property, plant, and equipment$526.5 
Other current assets0.2 
Other current liabilities(0.4)
Other long-term liabilities(75.1)
Noncontrolling interest(45.1)
Total purchase price$406.1 
Delilah I  
Asset Acquisition  
Allocation of purchase price
The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at the date of the acquisition.
(in millions)
Other current assets$0.1 
Net property, plant, and equipment579.8 
Other long-term assets12.4 
Other long-term liabilities(78.3)
Noncontrolling interest(51.5)
Total purchase price$462.5 
Samson I  
Asset Acquisition  
Allocation of purchase price
The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at the date of the original acquisition.
(in millions)
Accounts receivable$0.5 
Other current assets0.7 
Net property, plant, and equipment497.2 
Other long-term assets12.3 
Accounts payable(0.5)
Other current liabilities(0.8)
Other long-term liabilities(186.4)
Noncontrolling interest(65.7)
Total purchase price$257.3 
Maple Flats  
Asset Acquisition  
Allocation of purchase price
The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at the date of the acquisition.
(in millions)
Net property, plant, and equipment$469.5 
Other long-term assets44.5 
Other long-term liabilities(34.9)
Noncontrolling interest(47.9)
Total purchase price$431.2 
Sapphire Sky  
Asset Acquisition  
Allocation of purchase price
The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at the date of the acquisition.
(in millions)
Accounts receivable$0.8 
Net property, plant, and equipment642.6 
Other long-term assets1.4 
Accounts payable(1.0)
Other long-term liabilities(152.0)
Noncontrolling interest(49.2)
Total purchase price$442.6 
v3.25.4
Operating Revenues (Tables)
12 Months Ended
Dec. 31, 2025
Disaggregation of Operating Revenues  
Operating revenues disaggregated by revenue source
(in millions)WisconsinIllinoisOther StatesTotal Utility
Operations
Non-Utility Energy InfrastructureCorporate
and Other
Reconciling
Eliminations
WEC Energy Group Consolidated
Year ended December 31, 2025      
Electric$5,529.6 $ $ $5,529.6 $ $ $ $5,529.6 
Natural gas1,741.6 1,717.6 508.1 3,967.3 47.0  (44.5)3,969.8 
Total regulated revenues7,271.2 1,717.6 508.1 9,496.9 47.0  (44.5)9,499.4 
Other non-utility revenues  21.8 21.8 243.6  (9.2)256.2 
Total revenues from contracts with customers7,271.2 1,717.6 529.9 9,518.7 290.6  (53.7)9,755.6 
Other operating revenues24.3 (34.0)(2.4)(12.1)479.6  (423.0)
(1)
44.5 
Total operating revenues$7,295.5 $1,683.6 $527.5 $9,506.6 $770.2 $ $(476.7)$9,800.1 

(in millions)WisconsinIllinoisOther StatesTotal Utility
Operations
Non-Utility Energy InfrastructureCorporate
and Other
Reconciling
Eliminations
WEC Energy Group Consolidated
Year ended December 31, 2024      
Electric$4,908.4 $— $— $4,908.4 $— $— $— $4,908.4 
Natural gas1,402.4 1,499.6 419.7 3,321.7 48.4 — (46.0)3,324.1 
Total regulated revenues6,310.8 1,499.6 419.7 8,230.1 48.4 — (46.0)8,232.5 
Other non-utility revenues— — 20.4 20.4 223.9 — (9.1)235.2 
Total revenues from contracts with customers6,310.8 1,499.6 440.1 8,250.5 272.3 — (55.1)8,467.7 
Other operating revenues19.7 102.8 9.7 132.2 419.0 — (419.0)
(1)
132.2 
Total operating revenues$6,330.5 $1,602.4 $449.8 $8,382.7 $691.3 $— $(474.1)$8,599.9 

(in millions)WisconsinIllinoisOther StatesTotal Utility
Operations
Non-Utility Energy InfrastructureCorporate
and Other
Reconciling
Eliminations
WEC Energy Group Consolidated
Year Ended December 31, 2023      
Electric$4,994.6 $— $— $4,994.6 $— $— $— $4,994.6 
Natural gas1,606.7 1,480.5 493.7 3,580.9 61.9 — (60.2)3,582.6 
Total regulated revenues6,601.3 1,480.5 493.7 8,575.5 61.9 — (60.2)8,577.2 
Other non-utility revenues— — 19.6 19.6 197.5 0.1 (9.1)208.1 
Total revenues from contracts with customers6,601.3 1,480.5 513.3 8,595.1 259.4 0.1 (69.3)8,785.3 
Other operating revenues24.6 77.3 5.8 107.7 407.1 — (407.1)
(1)
107.7 
Total operating revenues$6,625.9 $1,557.8 $519.1 $8,702.8 $666.5 $0.1 $(476.4)$8,893.0 

(1)    Amounts eliminated represent lease revenues related to certain plants that We Power leases to WE to supply electricity to its customers. Lease payments are billed from We Power to WE and then recovered in WE's rates as authorized by the PSCW and the FERC. WE operates the plants and is authorized by the PSCW and Wisconsin state law to fully recover prudently incurred operating and maintenance costs in electric rates.
Revenues from contracts with customers | Electric  
Disaggregation of Operating Revenues  
Operating revenues disaggregated by revenue source
The following table disaggregates electric utility operating revenues into customer class:
Year Ended December 31
(in millions)202520242023
Residential$2,249.6 $1,996.3 $1,992.3 
Small commercial and industrial1,763.6 1,613.0 1,641.1 
Large commercial and industrial1,057.8 942.6 978.4 
Other30.9 30.2 30.5 
Total retail revenues5,101.9 4,582.1 4,642.3 
Wholesale107.6 102.6 120.4 
Resale267.6 176.7 195.4 
Steam28.4 22.4 25.2 
Other utility revenues24.1 24.6 11.3 
Total electric utility operating revenues$5,529.6 $4,908.4 $4,994.6 
Revenues from contracts with customers | Natural gas  
Disaggregation of Operating Revenues  
Operating revenues disaggregated by revenue source
The following tables disaggregate natural gas utility operating revenues into customer class:
(in millions)WisconsinIllinoisOther StatesTotal Natural Gas Utility Operating Revenues
Year ended December 31, 2025  
Residential$1,100.2 $1,174.9 $316.5 $2,591.6 
Commercial and industrial563.9 320.0 164.4 1,048.3 
Total retail revenues1,664.1 1,494.9 480.9 3,639.9 
Transportation105.1 291.8 38.8 435.7 
Other utility revenues (1) (2)
(27.6)(69.1)(11.6)(108.3)
Total natural gas utility operating revenues$1,741.6 $1,717.6 $508.1 $3,967.3 

(in millions)WisconsinIllinoisOther StatesTotal Natural Gas Utility Operating Revenues
Year ended December 31, 2024   
Residential$893.1 $945.5 $250.5 $2,089.1 
Commercial and industrial416.8 274.5 123.9 815.2 
Total retail revenues1,309.9 1,220.0 374.4 2,904.3 
Transportation96.8 272.2 33.6 402.6 
Other utility revenues (1)
(4.3)7.4 11.7 14.8 
Total natural gas utility operating revenues$1,402.4 $1,499.6 $419.7 $3,321.7 
(in millions)WisconsinIllinoisOther StatesTotal Natural Gas Utility Operating Revenues
Year Ended December 31, 2023   
Residential$1,012.0 $966.0 $324.4 $2,302.4 
Commercial and industrial506.7 267.1 175.3 949.1 
Total retail revenues1,518.7 1,233.1 499.7 3,251.5 
Transportation93.0 231.9 32.5 357.4 
Other utility revenues (1)
(5.0)15.5 (38.5)(28.0)
Total natural gas utility operating revenues$1,606.7 $1,480.5 $493.7 $3,580.9 

(1)    Includes the revenues subject to the purchased gas recovery mechanisms of our utilities, which fluctuate by segment based on actual natural gas costs incurred at our utilities, compared with the recovery of natural gas costs that were anticipated in rates.

(2)    For our Illinois segment, includes a $75.0 million reduction in revenues recorded in the fourth quarter of 2025 for future billing credits to customers, based on the terms of a proposed settlement in February 2026 to resolve open QIP and UEA proceedings.
Revenues from contracts with customers | Other non-utility revenues  
Disaggregation of Operating Revenues  
Operating revenues disaggregated by revenue source
Other non-utility operating revenues consist primarily of the following:
Year Ended December 31
(in millions)202520242023
Renewable generation revenues$209.8 $190.5 $164.9 
We Power revenues24.6 24.3 23.5 
Appliance service revenues21.8 20.4 19.6 
Other — 0.1 
Total other non-utility operating revenues$256.2 $235.2 $208.1 
Other operating revenues  
Disaggregation of Operating Revenues  
Operating revenues disaggregated by revenue source
Other operating revenues consist primarily of the following:
Year Ended December 31
(in millions)202520242023
Late payment charges$48.1 $48.5 $56.5 
Bespoke resources current return (1)
4.1 — — 
Alternative revenues (2)
(67.7)79.8 47.0 
Other60.0 3.9 4.2 
Total other operating revenues$44.5 $132.2 $107.7 

(1)    Bespoke resources current return consists of carrying costs earned during the construction of bespoke resources assigned to WE's VLCs. See Note 1(d), Operating Revenues, for more information.

(2)    Alternative revenues consist of amounts to be recovered or refunded to customers subject to decoupling mechanisms, wholesale true-ups, and conservation improvement rider true-ups. Negative amounts can result from alternative revenues being reversed to revenues from contracts with customers as the customer is billed for these alternative revenues. For more information about our alternative revenues, see Note 1(d), Operating Revenues.
v3.25.4
Credit Losses (Tables)
12 Months Ended
Dec. 31, 2025
Credit Loss [Abstract]  
Schedule of gross receivables and related allowances for credit losses
We have included tables below that show our gross third-party receivable balances and the related allowance for credit losses at December 31, 2025 and 2024, by reportable segment.
(in millions)WisconsinIllinoisOther StatesTotal Utility
Operations
Non-Utility Energy InfrastructureCorporate
and Other
WEC Energy Group Consolidated
December 31, 2025
Accounts receivable and unbilled revenues$1,368.8 $654.8 $130.2 $2,153.8 $50.3 $7.3 $2,211.4 
Allowance for credit losses61.7 82.3 4.7 148.7   148.7 
Accounts receivable and unbilled revenues, net (1)
$1,307.1 $572.5 $125.5 $2,005.1 $50.3 $7.3 $2,062.7 
Total accounts receivable, net – past due greater than 90 days (1)
$46.4 $36.8 $6.6 $89.8 $ $ $89.8 
Past due greater than 90 days – collection risk mitigated by regulatory mechanisms (1)
94.6 %100.0 % %89.9 % % %89.9 %

(in millions)WisconsinIllinoisOther StatesTotal Utility
Operations
Non-Utility Energy InfrastructureCorporate
and Other
WEC Energy Group Consolidated
December 31, 2024
Accounts receivable and unbilled revenues$1,149.9 $535.6 $100.6 $1,786.1 $40.0 $6.0 $1,832.1 
Allowance for credit losses73.6 83.9 5.3 162.8 — — 162.8 
Accounts receivable and unbilled revenues, net (1)
$1,076.3 $451.7 $95.3 $1,623.3 $40.0 $6.0 $1,669.3 
Total accounts receivable, net – past due greater than 90 days (1)
$51.8 $30.1 $2.5 $84.4 $— $— $84.4 
Past due greater than 90 days – collection risk mitigated by regulatory mechanisms (1)
93.8 %100.0 %— %93.2 %— %— %93.2 %

(1)    Our exposure to credit losses for certain regulated utility customers is mitigated by regulatory mechanisms we have in place. Specifically, rates related to all of the customers in our Illinois segment, as well as the residential rates of WE, WPS, and WG in our Wisconsin segment, include riders or other mechanisms for cost recovery or refund of uncollectible expense based on the difference between the actual provision for credit losses and the amounts recovered in rates. As a result, at December 31, 2025, $1,290.2 million, or 62.5%, of our net accounts receivable and unbilled revenues balance had regulatory protections in place to mitigate the exposure to credit losses. See Note 26, Regulatory Environment, for more information on PGL and NSG's UEA rider for cost recovery or refund of uncollectible expense based on the difference between actual uncollectible write-offs and amounts recovered in rates.
Rollforward of the allowances for credit losses by reportable segment
A rollforward of the allowance for credit losses by reportable segment for the years ended December 31, 2025, 2024, and 2023, is included below:
(in millions)
WisconsinIllinoisOther StatesWEC Energy Group Consolidated
Balance at January 1, 2025$73.6 $83.9 $5.3 $162.8 
Provision for credit losses85.0 55.8 2.0 142.8 
Provision for credit losses deferred for future recovery or refund4.9 (28.7) (23.8)
Write-offs charged against the allowance(151.4)(81.2)(8.4)(241.0)
Recoveries of amounts previously written off49.6 52.5 5.8 107.9 
Balance at December 31, 2025$61.7 $82.3 $4.7 $148.7 

On a consolidated basis, there was a $14.1 million decrease in the allowance for credit losses during the year ended December 31, 2025. This decrease is largely driven by customer write-offs in Wisconsin in addition to a decrease in past due account balances in Wisconsin that we believe was related to a continued focus on collection efforts and lower energy bills in the spring and summer months, enabling customers to pay down their arrears.
(in millions)
WisconsinIllinoisOther StatesWEC Energy Group Consolidated
Balance at January 1, 2024$77.4 $109.7 $6.4 $193.5 
Provision for credit losses52.1 52.3 0.5 104.9 
Provision for credit losses deferred for future recovery or refund43.8 (8.0)— 35.8 
Write-offs charged against the allowance(141.8)(95.0)(6.6)(243.4)
Recoveries of amounts previously written off42.1 24.9 5.0 72.0 
Balance at December 31, 2024$73.6 $83.9 $5.3 $162.8 

On a consolidated basis, there was a $30.7 million decrease in the allowance for credit losses during the year ended December 31, 2024, largely driven by customer write-offs. We also believe that the lower energy costs that customers were seeing, which were driven by warmer than normal weather conditions during most of 2024 and low average natural gas prices, contributed to a reduction in past due accounts receivable balances and a related decrease in the allowance for credit losses.
(in millions)
WisconsinIllinoisOther StatesWEC Energy Group Consolidated
Balance at January 1, 2023$82.0 $111.0 $6.3 $199.3 
Provision for credit losses40.9 26.3 4.8 72.0 
Provision for credit losses deferred for future recovery or refund52.5 35.8 — 88.3 
Write-offs charged against the allowance(131.6)(85.4)(6.6)(223.6)
Recoveries of amounts previously written off33.6 22.0 1.9 57.5 
Balance at December 31, 2023$77.4 $109.7 $6.4 $193.5 
On a consolidated basis, there was a $5.8 million decrease in the allowance for credit losses during the year ended December 31, 2023, primarily related to lower customer energy costs (driven by the warmer weather during the fourth quarter of 2023 when compared to the same quarter in 2022 and lower natural gas prices), which contributed to a reduction in past due accounts receivable balances and a related decrease in the allowance for credit losses. Customer write-offs also contributed to the decrease in the allowance for credit losses.
v3.25.4
Regulatory Assets and Liabilities (Tables)
12 Months Ended
Dec. 31, 2025
Regulatory Assets and Liabilities Disclosure [Abstract]  
Schedule of regulatory assets
The following regulatory assets were reflected on our balance sheets as of December 31:
(in millions)20252024See Note
Regulatory assets (1) (2)
Plant retirement related items (3)
$768.6 $810.5 
Environmental remediation costs (4)
566.0 570.1 24
Pension and OPEB costs (5)
564.5 684.9 20, 26
Income tax related items493.4 438.5 16
AROs185.1 166.7 1(l), 9
Uncollectible expense123.9 151.5 5
SSR (6)
92.6 102.9 
Securitization67.5 76.5 23
Derivatives57.7 38.2 1(s)
Decoupling43.8 110.0 1(d)
Bluewater (7)
37.7 57.7 
Finance and operating leases36.0 22.0 15
Electric transmission costs (8)
30.7 0.4 
Energy efficiency programs (9)
11.6 26.5 
Other, net94.5 122.3 
Total regulatory assets$3,173.6 $3,378.7 
Balance sheet presentation
Other current assets$17.3 $39.0 
Regulatory assets3,156.3 3,339.7 
Total regulatory assets$3,173.6 $3,378.7 

(1)    Based on prior and current rate treatment, we believe it is probable that our utilities will continue to recover from customers the regulatory assets in this table. In accordance with GAAP, our regulatory assets do not include the allowance for ROE that is capitalized for regulatory purposes. This allowance was $20.9 million and $26.7 million at December 31, 2025 and 2024, respectively.

(2)    As of December 31, 2025, we had $183.1 million of regulatory assets not earning a return, $1.3 million of regulatory assets earning a return based on short-term interest rates, $106.1 million of regulatory assets earning a return based on long-term interest rates, and $5.5 million of regulatory assets earning a return based on the applicable utility's ROE. The regulatory assets not earning a return primarily relate to certain environmental remediation costs, decoupling mechanisms, electric transmission costs, unamortized loss on reacquired debt, and uncollectible expense. The other regulatory assets in the table either earn a return at the applicable utility's weighted average cost of capital or the cash has not yet been expended, in which case the regulatory assets are offset by liabilities.

(3)    Primarily represents the net book value of power plants we have both abandoned and retired. For all of these plants, we have approval to collect a return of their remaining net book value. We also have approval to collect a return on all but $100 million of their remaining net book value. For information on the securitization of this $100 million, see Note 23, Variable Interest Entities. These regulatory assets are amortized on a straight-line basis, using the composite depreciation rates approved before the plants were retired, and the amortization is included in depreciation and amortization in the income statement.

(4)    As of December 31, 2025, we had made cash expenditures of $81.9 million related to these environmental remediation costs. The remaining $484.1 million represents our estimated future cash expenditures.

(5)    Primarily represents the unrecognized future pension and OPEB costs related to our defined benefit pension and OPEB plans. We are authorized recovery of these regulatory assets over the average remaining service life of each plan.

(6)    This regulatory asset relates to WE's 2014 announcement to retire the PIPP. Despite WE's intent to retire the PIPP, MISO designated the PIPP as a SSR, which meant the PIPP's operation was necessary for reliability, and the plant could not be shut down until new generation or transmission facilities were built. In December 2014, the PSCW authorized escrow accounting for WE's SSR revenues because of the fluctuations in the actual revenues WE received under the PIPP SSR agreements. The rate order WE received from the PSCW in December 2019 authorized recovery of this SSR regulatory asset over a 15-year period that began on January 1, 2020.

(7)    Primarily relates to costs associated with the long-term service agreements our Wisconsin utilities have with Bluewater for natural gas storage services. The PSCW has approved escrow accounting for these costs. As a result, our Wisconsin utilities defer as a regulatory asset or liability the difference between actual storage costs and those included in rates until recovery or refund is authorized in a future rate proceeding.
(8)    In accordance with the PSCW's approval of escrow accounting for ATC and MISO network transmission expenses for our Wisconsin electric utilities, WE and WPS defer as a regulatory asset or liability the difference between actual transmission costs and those included in rates until recovery or refund is authorized in a future rate proceeding.

(9)    Represents amounts recoverable from customers related to programs at the utilities designed to meet energy efficiency standards.
Schedule of regulatory liabilities
The following regulatory liabilities were reflected on our balance sheets as of December 31:
(in millions)20252024See Note
Regulatory liabilities
Income tax related items$1,802.4 $1,825.4 16
Removal costs (1)
1,584.7 1,458.2 
Pension and OPEB benefits (2)
301.5 308.5 20, 26
Proposed settlement related to QIP and UEA riders125.0 — 26
Energy costs refundable through rate adjustments119.2 160.8 1(d)
Uncollectible expense73.1 47.2 5
Earnings sharing mechanisms35.8 7.1 26
Derivatives27.4 36.9 1(s)
MERC property tax tracker (3)
23.1 19.3 
Revenue requirements of renewable generation facilities (4)
14.5 44.2 
Other, net103.5 95.7 
Total regulatory liabilities$4,210.2 $4,003.3 
Balance sheet presentation
Other current liabilities$88.9 $45.3 
Regulatory liabilities4,121.3 3,958.0 
Total regulatory liabilities$4,210.2 $4,003.3 

(1)    Represents amounts collected from customers to cover the future cost of property, plant, and equipment removals that are not legally required. Legal obligations related to the removal of property, plant, and equipment are recorded as AROs. See Note 9, Asset Retirement Obligations, for more information on our legal obligations.

(2)    Primarily represents the unrecognized future pension and OPEB benefits related to our defined benefit pension and OPEB plans. We will amortize these regulatory liabilities into net periodic benefit cost over the average remaining service life of each plan.

(3)    MERC defers as a regulatory asset or liability the difference between actual property tax expense and the amount included in rates until
recovery or refund is authorized in a future rate proceeding.
(4)    These amounts represent the deferral of the incremental revenue requirement impact from the delayed in-service date of certain renewable generation facilities constructed by our electric utilities.
v3.25.4
Property, Plant, and Equipment (Tables)
12 Months Ended
Dec. 31, 2025
Property, Plant and Equipment [Abstract]  
Property, Plant and Equipment - Balances
Property, plant, and equipment consisted of the following at December 31:
(in millions)20252024
Electric – generation$7,998.3 $6,685.0 
Electric – distribution10,048.9 9,298.9 
Natural gas – distribution, storage, and transmission16,175.0 15,673.0 
Property, plant, and equipment to be retired, net621.7 906.3 
Other2,431.2 2,410.8 
Less: Accumulated depreciation10,180.2 9,401.0 
Net27,094.9 25,573.0 
CWIP3,364.4 1,653.6 
Net utility and non-utility property, plant, and equipment30,459.3 27,226.6 
We Power generation3,250.7 3,284.3 
Renewable generation5,252.4 4,720.8 
Natural gas storage299.6 298.6 
Net non-utility energy infrastructure8,802.7 8,303.7 
Corporate services167.6 172.3 
Other11.3 14.1 
Less: Accumulated depreciation1,559.1 1,393.9 
Net7,422.5 7,096.2 
CWIP60.8 41.3 
Net other property, plant, and equipment7,483.3 7,137.5 
Property under finance leases351.8 291.3 
Less: Accumulated amortization16.3 10.0 
Net leased facilities335.5 281.3 
Total property, plant, and equipment$38,278.1 $34,645.4 
Schedule of activity related to severance liability Activity related to these severance liabilities for the years ended December 31 was as follows:
(in millions)202520242023
Severance liability at January 1$13.4 $17.8 $16.2 
Severance expense (3.9)
(1)
1.6 
Severance payments(0.7)(0.5)— 
Total severance liability at December 31$12.7 $13.4 $17.8 

(1)    The severance accrual was lowered in 2024 due to workforce realignment efforts.
v3.25.4
Jointly Owned Utility Facilities (Tables)
12 Months Ended
Dec. 31, 2025
Jointly owned utility facilities in-service  
Jointly owned utility facilities  
Schedule of jointly owned utility facilities
Information related to jointly owned utility facilities in-service at December 31, 2025 was as follows:
CompanyJointly-Owned Utility FacilitiesOwnership
Share of Capacity (MW)
In-Service /Acquisition Date
Operating OwnerProperty, Plant, and EquipmentAccumulated DepreciationCWIP
(in millions, except for percentages and MW)
We Power (1)
ER 1 & ER 2 (2)
83.34 %1,083.4 2010 & 2011WE$2,489.4 $(542.0)$4.6 
WPS
Weston Unit 4 (2)
70.0 %379.8 2008WPS600.6 (242.7)4.5 
WPS
Columbia Units 1 & 2 (2)
27.5 %306.2 1975 & 1978WPL439.1 (201.6)5.0 
WPS
Forward Wind (3)
44.6 %61.5 2008WPS120.3 (63.3)13.9 
WPS
Two Creeks (4)
66.7 %100.0 2020WPS135.7 (22.9) 
WPS
Badger Hollow I (4)
66.7 %100.0 2021WPS146.0 (19.0) 
WPS
Red Barn (3)
90.0 %82.4 2023WPS150.7 (12.8) 
WE
West Riverside (2) (5)
27.5 %190.2 2023 & 2024WPL223.6 (36.7)2.2 
WE
Badger Hollow II (4)
66.7 %100.0 2023WE179.3 (11.8) 
WE, WPS
Paris Solar (4)
90.0 %180.0 2024WE359.3 (11.0) 
WE, WPS
Paris Battery
90.0 %99.0 
2025
WE
236.8 (5.5) 
WE, WPS
Darien Solar (4)
90.0 %225.0 
2025
WE
460.1 (10.7) 

(1)    We Power leases its ownership interest in ER 1 and ER 2 to WE.

(2)    Capacity is based on rated capacity, which is the net power output under average operating conditions with equipment in an average state of repair as of a given month in a given year. Values are primarily based on the net dependable expected capacity ratings for summer 2026 established by tests and may change slightly from year to year. The summer period is the most relevant for capacity planning purposes. This is a result of continually reaching demand peaks in the summer months, primarily due to air conditioning demand.

(3)     Capacity for wind generating facilities is based on nameplate capacity, which is the amount of energy a turbine should produce at optimal wind speeds.

(4)     Capacity for solar generating facilities is based on nameplate capacity, which is the maximum output that a generator should produce at continuous full power.

(5)    WE acquired a 13.8% ownership interest in June 2023 and acquired an additional 13.7% ownership interest in May 2024. See Note 2, Acquisitions, for more information.
Jointly owned utility facilities approved by the PSCW  
Jointly owned utility facilities  
Schedule of jointly owned utility facilities
Information related to jointly owned utility facilities approved by the PSCW at December 31, 2025 was as follows:
CompanyJointly-Owned Utility FacilitiesOwnership
Share of Capacity (MW)
Date of Expected In-Service
CWIP
(in millions, except for percentages and MW)
WE, WPS
Koshkonong Solar
90.0 %270.0 
2026
$460.6 
WE, WPS
Koshkonong Battery
90.0 %149.0 
2027
150.7 
WE, WPS
Darien Battery
90.0 %68.0 
2027
68.3 
WE, WPS
High Noon Solar
90.0 %270.0 
2027
404.2 
WE, WPS
High Noon Battery
90.0 %149.0 
2027
150.8 
WE, WPS
Ursa Solar Electric Generation Facility
90.0 %180.0 
2027
57.1 
WE, WPS
Saratoga Solar
90.0 %135.0 
2028
39.2 
WE, WPS
Saratoga Battery
90.0 %45.0 
2028
53.2 
WE, WPS
Badger Hollow Wind Energy Generation Facility
90.0 %100.0 
2027
50.0 
WE, WPS
Whitetail
90.0 %60.0 
2027
9.0 
v3.25.4
Asset Retirement Obligations (Tables)
12 Months Ended
Dec. 31, 2025
Asset Retirement Obligation Disclosure [Abstract]  
Schedule of changes to asset retirement obligations
The following table shows changes to our AROs during the years ended December 31:
(in millions)202520242023
Balance as of January 1$580.0 $374.2 $479.3 
Accretion26.6 18.8 17.2 
Additions29.6 192.7 
(1)
24.0 
Revisions to estimated cash flows23.7 6.4 (133.5)
(2)
Liabilities settled(12.9)(12.1)(12.8)
Balance as of December 31$647.0 $580.0 $374.2 

(1)    AROs increased primarily as a result of AROs being recorded related to the new EPA CCR Rule that was enacted in April 2024. See Note 24, Commitments and Contingencies, for more information.

(2)    AROs decreased primarily due to revisions made to estimated cash flows for changes in removal cost estimates and settlements dates for mains and services at PGL and NSG.
v3.25.4
Goodwill and Intangibles (Tables)
12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of goodwill balances by segment The table below shows our goodwill balances by segment at December 31, 2025. We had no changes to the carrying amount of goodwill during the years ended December 31, 2025 and 2024.
(in millions) Wisconsin IllinoisOther StatesNon-Utility Energy InfrastructureTotal
Goodwill (1)
$2,104.3 $758.7 $183.2 $6.6 $3,052.8 

(1)    We had no accumulated impairment losses related to our goodwill as of December 31, 2025.
Schedule of intangible liabilities obtained through acquisitions by WECI
The intangible liabilities below were all obtained through acquisitions by WECI.
December 31, 2025December 31, 2024
(in millions)Gross Carrying AmountAccumulated AmortizationNet Carrying AmountGross Carrying AmountAccumulated AmortizationNet Carrying Amount
PPAs (1)
$751.2 $(176.5)$574.7 $679.6 $(119.3)$560.3 
Proxy revenue swap (2)
7.2 (4.9)2.3 7.2 (4.2)3.0 
Interconnection agreements (3)
4.7 (1.4)3.3 4.7 (1.2)3.5 
Total intangible liabilities$763.1 $(182.8)$580.3 $691.5 $(124.7)$566.8 

(1)    Represents PPAs related to the acquisition of Blooming Grove, Tatanka Ridge, Jayhawk, Thunderhead, Samson I, Sapphire Sky, Delilah I, and Hardin III expiring between 2030 and 2040. The weighted-average remaining useful life of the PPAs is 10 years. See Note 2, Acquisitions, for more information on recent WECI acquisitions.

(2)    Represents an agreement with a counterparty to swap the market revenue of Upstream's wind generation for fixed quarterly payments over 10 years, which expires in 2029. The remaining useful life of the proxy revenue swap is three years.
(3)    Represents interconnection agreements related to the acquisitions of Tatanka Ridge and Bishop Hill III, expiring in 2040 and 2041, respectively. These agreements relate to payments for connecting our facilities to the infrastructure of another utility to facilitate the movement of power onto the electric grid. The weighted-average remaining useful life of the interconnection agreements is 15 years.
Schedule of amortization over the next five years Amortization for the next five years is estimated to be:
For the Years Ending December 31
(in millions)20262027202820292030
Amortization to be recorded as an increase to operating revenues$59.9 $59.9 $59.9 $59.9 $59.9 
Amortization to be recorded as a decrease to other operation and maintenance0.2 0.2 0.2 0.2 0.2 
v3.25.4
Common Equity (Tables)
12 Months Ended
Dec. 31, 2025
Stockholders' Equity Note [Abstract]  
Schedule of stock-based compensation expense and related tax benefit recognized in income
The following table summarizes our pre-tax stock-based compensation expense and the related tax benefit recognized in income for the years ended December 31:
(in millions)202520242023
Stock options$4.1 $4.9 $5.3 
Restricted stock6.2 7.6 6.6 
Performance units37.9 26.8 (2.2)
(1)
Stock-based compensation expense$48.2 $39.3 $9.7 
Related tax benefit$13.2 $10.8 $2.7 

(1)    The reduction in expense was due to a decrease in the fair value of the outstanding performance units.
Schedule of stock option activity
The following is a summary of our stock option activity during 2025:
Stock OptionsNumber of OptionsWeighted-Average Exercise Price
Weighted-Average Remaining Contractual Life
(in years)
Aggregate Intrinsic Value (in millions)
Outstanding as of January 1, 20252,916,902 $82.32 
Granted231,024 94.55 
Exercised(575,758)67.92 
Forfeited(1,351)91.11 
Expired(1,330)52.90 
Outstanding as of December 31, 20252,569,487 86.65 5.3$48.3 
Exercisable as of December 31, 20251,937,953 85.29 4.4$39.1 
Schedule of restricted stock activity
The following restricted stock activity occurred during 2025:
Restricted SharesNumber of SharesWeighted-Average Grant Date Fair Value
Outstanding and unvested as of January 1, 2025105,242 $87.61 
Granted79,170 94.55 
Released(58,725)88.48 
Forfeited(6,774)90.88 
Outstanding and unvested as of December 31, 2025118,913 91.61 
Schedule of Common Stock Outstanding
We had the following changes to our outstanding common stock during the years ended December 31, 2025 and 2024:
20252024
Common stock shares outstanding at beginning of period317,680,855 315,434,531 
Shares issued:
At-the-market offering program6,579,783 1,030,674 
Stock-based compensation 609,995 455,474 
401(k)247,889 336,800 
Stock investment plan342,997 423,376 
Common stock shares outstanding at end of period325,461,519 317,680,855 
Schedule of shares purchased to fulfill exercised stock options and restricted stock awards
The following is a summary of shares purchased to fulfill exercised stock options and restricted stock awards during the years ended December 31:
(in millions, except share amounts)202520242023
Shares purchased13,795 23,292 182,795 
Cost of shares purchased$1.3 $3.2 $16.6 
Schedule of common stock dividends declared
During the year ended December 31, 2025, our Board of Directors declared common stock dividends which are summarized below:
Date DeclaredDate PayablePer SharePeriod
January 16, 2025March 1, 2025$0.8925First quarter
April 17, 2025June 1, 2025$0.8925Second quarter
July 17, 2025September 1, 2025$0.8925Third quarter
October 16, 2025December 1, 2025$0.8925Fourth quarter
Schedule of basic and diluted earnings per share
The following table shows the computation of our basic and diluted EPS for the years ended December 31:
(in millions, except per share amounts)202520242023
Numerator:
Net income attributed to common shareholders$1,557.5 $1,527.2 $1,331.7 
Denominator:
Weighted average basic shares outstanding321.9316.2315.4
Dilutive effect of stock-based compensation awards0.6 0.3 0.5 
Dilutive effect of convertible senior notes1.3 — — 
Weighted average diluted shares323.8 316.5 315.9 
Basic EPS$4.84 $4.83 $4.22 
Diluted EPS$4.81 $4.83 $4.22 
v3.25.4
Preferred Stock (Tables)
12 Months Ended
Dec. 31, 2025
Class of Stock Disclosures [Abstract]  
Schedule of preferred stock by class
The following table shows preferred stock authorized and outstanding at December 31, 2025 and 2024:
(in millions, except share and per share amounts)Shares AuthorizedShares OutstandingRedemption Price Per ShareTotal
WEC Energy Group
$0.01 par value Preferred Stock
15,000,000   $ 
WE
$100 par value, Six Per Cent. Preferred Stock
45,000 44,498  4.4 
$100 par value, Serial Preferred Stock 3.60% Series
2,286,500 260,000 $101 26.0 
$25 par value, Serial Preferred Stock
5,000,000    
WPS
$100 par value, Preferred Stock
1,000,000    
PGL
$100 par value, Cumulative Preferred Stock
430,000    
NSG
$100 par value, Cumulative Preferred Stock
160,000    
Total$30.4 
v3.25.4
Short-Term Debt and Lines of Credit (Tables)
12 Months Ended
Dec. 31, 2025
Short-Term Debt [Abstract]  
Short-term debt balances and their corresponding weighted-average interest rates
The following table shows our short-term borrowings and their corresponding weighted-average interest rates as of December 31:
(in millions, except percentages)20252024
Commercial paper
Amount outstanding at December 31$1,921.3 $1,114.4 
Average interest rate on amounts outstanding at December 313.89 %4.63 %
Operating expense loans
Amount outstanding at December 31 (1)
$3.4 $2.2 

(1)    Coyote Ridge, Tatanka Ridge, Samson I, and Jayhawk have entered into operating expense loans. In accordance with their limited liability company operating agreements, they received loans from the holders of their noncontrolling interests in proportion to their ownership interests.
Schedule of revolving credit facilities
The information in the table below relates to our revolving credit facilities used to support our commercial paper borrowing programs, including remaining available capacity under these facilities as of December 31:
(in millions)Maturity2025
Revolving credit facility (WEC Energy Group) (1) (2) (3)
August 2030$1,700.0 
Revolving credit facility (WE) (1) (2)
August 2030800.0 
Revolving credit facility (PGL) (1) (2)
August 2030600.0 
Revolving credit facility (WPS) (1) (2)
August 2030450.0 
Revolving credit facility (WG) (1) (4)
August 2030350.0 
Total short-term credit capacity $3,900.0 
Less:  
Letters of credit issued inside credit facilities $2.3 
Commercial paper outstanding 1,921.3 
Available capacity under existing facilities $1,976.4 

(1)    These revolving credit facilities have a renewal provision for two extensions, subject to lender approval. Each extension is for a period of one year.

(2)    In August 2025, the capacity of the credit facilities for each of WEC Energy Group, WE, PGL, and WPS was increased to $1,700.0 million, $800.0 million, $600.0 million, and $450.0 million, respectively, and the maturity for each facility was extended to August 2030.

(3)    In August 2025, WEC Energy Group terminated its $200.0 million bilateral credit facility.

(4)    In August 2025, WG extended the maturity of its credit facility to August 2030.
v3.25.4
Long-Term Debt (Tables)
12 Months Ended
Dec. 31, 2025
Debt Disclosure [Abstract]  
Schedule of long-term debt instruments
The following table is a summary of our long-term debt outstanding as of December 31:
20252024
(in millions)Maturity DateWeighted Average Interest RateBalanceWeighted Average Interest RateBalance
WEC Energy Group Senior Notes (unsecured)2026-20333.96 %$6,325.0 4.13 %$6,045.0 
WEC Energy Group Junior Notes (unsecured) (1) (2)
2055-20566.24 %1,350.0 6.72 %750.0 
WE Debentures (unsecured)2028-20954.55 %4,485.0 4.55 %3,935.0 
WEPCo Environmental Trust (secured, nonrecourse) (5) (10)
2026-20351.58 %78.8 1.58 %88.0 
WPS Senior Notes (unsecured)2028-20513.99 %1,975.0 4.17 %2,275.0 
WG Debentures (unsecured)2028-20464.34 %940.0 3.92 %840.0 
PGL First and Refunding Mortgage Bonds (secured) (3)
2027-20473.56 %1,995.0 3.56 %1,995.0 
NSG First Mortgage Bonds (secured) (4)
2027-20433.81 %177.0 3.81 %177.0 
MERC Senior Notes (unsecured)2027-20473.64 %210.0 3.04 %210.0 
MGU Senior Notes (unsecured)2027-20474.38 %190.0 3.45 %175.0 
UMERC Senior Notes (unsecured)2029-20354.23 %280.0 3.26 %160.0 
Bluewater Gas Storage Senior Notes (unsecured) (5)
2026-20474.07 %128.0 4.07 %131.9 
ATC Holding Senior Notes (unsecured)2028-20304.02 %390.0 4.05 %475.0 
We Power Subsidiaries Notes (secured, nonrecourse) (5) (6)
2026-20415.71 %769.9 5.67 %814.3 
WECC Notes (unsecured)20286.94 %50.0 6.94 %50.0 
WECI Wind Holding I Senior Notes (secured, nonrecourse) (5) (7)
2026-20322.75 %202.1 2.75 %246.4 
WECI Wind Holding II Senior Notes (secured, nonrecourse) (5) (8)
2026-20316.38 %147.9 6.38 %167.6 
WECI Energy Holding III Senior Notes (secured, nonrecourse) (5) (9)
2026-20395.73 %446.2 5.73 %488.7 
Total 20,139.9 19,023.9 
Jayhawk acquisition7.5 7.5 
Unamortized debt issuance costs(110.4)(103.2)
Unamortized discount, net and other(19.5)(21.1)
Total long-term debt, including current portion20,017.5 18,907.1 
Current portion of long-term debt(1,519.4)(1,729.0)
Total long-term debt$18,498.1 $17,178.1 

(1)    In November 2025, we issued our 2025 Junior Notes. Our 2025 Junior Notes are fixed-to-fixed reset rate junior subordinated notes. The rate for our 2025 Junior Notes was 5.625% as of December 31, 2025. The rate for our 2025 Junior Notes will reset on May 15, 2031; provided the reset rate will not be less than 5.625%.

(2)    In December 2024, we issued our 2024A Junior Notes and 2024B Junior Notes. Our 2024A Junior Notes and 2024B Junior Notes are fixed-to-fixed reset rate junior subordinated notes. The rate for our 2024A Junior Notes was 6.69% as of December 31, 2025. The rate for our 2024A Junior Notes will reset on June 15, 2030. The rate for our 2024B Junior Notes was 6.74% as of December 31, 2025. The rate for our 2024B Junior Notes will reset on June 15, 2035.

(3)    PGL's First Mortgage Bonds are subject to the terms and conditions of PGL's First Mortgage Indenture dated January 2, 1926, as supplemented. Under the terms of the Indenture, substantially all property owned by PGL is pledged as collateral for these outstanding debt securities.

PGL has used certain First Mortgage Bonds to secure tax exempt interest rates. The Illinois Finance Authority has issued Tax Exempt Bonds, and the proceeds from the sale of these bonds were loaned to PGL. In return, PGL issued $100 million of collateralized First Mortgage Bonds.

(4)    NSG's First Mortgage Bonds are subject to the terms and conditions of NSG's First Mortgage Indenture dated April 1, 1955, as supplemented. Under the terms of the Indenture, substantially all property owned by NSG is pledged as collateral for these outstanding debt securities.

(5)    The long-term debt of Bluewater, WECI Wind Holding I, WECI Wind Holding II, WECI Energy Holding III, WEPCo Environmental Trust, and We Power's subsidiaries requires periodic principal payments.

(6)    We Power's subsidiaries' senior notes are secured by a collateral assignment of the leases between We Power's subsidiaries and WE related to PWGS and ERGS, as applicable.
(7)    WECI Wind Holding I's Senior Notes are secured by a first priority security interest in the ownership interest of its subsidiaries, as well as a pledge of equity in WECI Wind Holding I.

(8)    WECI Wind Holding II's Senior Notes are secured by a first priority security interest in the ownership interest of its subsidiaries, as well as a pledge of equity in WECI Wind Holding II.

(9)    WECI Energy Holding III's Senior Notes are secured by a first priority security interest in the ownership interest of its subsidiaries, as well as a pledge of equity in WECI Energy Holding III.

(10)    WEPCo Environmental Trust’s ETBs are secured by a pledge of and lien on environmental control property, which includes the right to impose, collect and receive a non-bypassable environmental control charge paid by all of WE's retail electric distribution customers, the right to obtain true-up adjustments of the environmental control charges, and all revenues or other proceeds arising from those rights and interests. See Note 23, Variable Interest Entities, for more information.
Schedule of convertible debt The following is a summary of our convertible debt instruments as of December 31, 2025:
(in millions)
Principal Amount
Unamortized Debt Issuance Costs
Net Carrying Amount
Fair Value Amount (1)
2027 Notes
$862.5 $(4.7)$857.8 $977.8 
2028 Notes900.0 (8.5)891.5 912.6 
2029 Notes
862.5 (6.8)855.7 1,011.7 

(1)    The fair values are categorized in Level 2 of the fair value hierarchy. See Note 1(r), Fair Value Measurements, for more information on the levels of the fair value hierarchy.
Schedule of convertible debt interest expense
The following table provides a summary of the interest expense recorded for each of the 2027 Notes, 2028 Notes, and 2029 Notes for the year ended December 31:
(in millions)20252024
2027 Notes
Contractual interest expense
$37.7 $22.3 
Amortization of debt issuance costs
3.3 1.9 
Total interest expense – 2027 Notes41.0 24.2 
2028 Notes
Contractual interest expense$17.0 $— 
Amortization of debt issuance costs1.8 — 
Total interest expense – 2028 Notes18.8 — 
2029 Notes
Contractual interest expense
37.7 22.3 
Amortization of debt issuance costs
2.0 1.2 
Total interest expense – 2029 Notes$39.7 $23.5 
Schedule of current maturities of long-term debt
The following table shows the long-term debt securities maturing within one year of December 31, 2025:
(in millions)Interest Rate
Maturity Date (1)
Principal Amount
WEC Energy Group Senior Notes (unsecured)4.75%January$1,000.0 
WEC Energy Group Senior Notes (unsecured)5.60%September350.0 
WEPCo Environmental Trust (secured, nonrecourse)1.58%Semi-annually9.3 
Bluewater Gas Storage Senior Notes (unsecured)3.76%Semi-annually3.1 
Bluewater Gas Storage Senior Notes (unsecured)5.41%Semi-annually1.0 
We Power Subsidiaries Notes – PWGS (secured, nonrecourse) 4.91%Monthly8.9 
We Power Subsidiaries Notes – ERGS (secured, nonrecourse)5.209%Semi-annually17.1 
We Power Subsidiaries Notes – ERGS (secured, nonrecourse) 4.673%Semi-annually12.8 
We Power Subsidiaries Notes – PWGS (secured, nonrecourse)6.00%Monthly7.9 
WECI Wind Holding I Senior Notes (secured, nonrecourse)2.75%Semi-annually45.1 
WECI Wind Holding II Senior Notes (secured, nonrecourse)6.38%Semi-annually22.6 
WECI Energy Holding III Senior Notes (secured, nonrecourse)5.73%Semi-annually41.6 
Total $1,519.4 

(1)    Maturity dates listed as semi-annually and monthly are associated with debt that requires periodic principal payments.
Schedule of future maturities of long-term debt
The following table shows the future maturities of our long-term debt outstanding as of December 31, 2025:
(in millions)Payments
2026$1,519.4 
20272,137.3 
20283,203.2 
20292,943.4 
20301,691.9 
Thereafter8,644.7 
Total$20,139.9 
v3.25.4
Leases (Tables)
12 Months Ended
Dec. 31, 2025
Leases [Abstract]  
Schedule of lease expense and supplemental cash flow information for leases
The components of lease expense and supplemental cash flow information related to our leases for the years ended December 31 are as follows:
(in millions)202520242023
Finance lease expense
Amortization of right of use assets (1)
$1.1 $0.2 $— 
Interest on lease liabilities (2)
6.9 1.8 0.8 
Operating lease expense (3)
7.8 5.2 4.7 
Short-term lease expense (3)
0.2 0.6 1.2 
Total lease expense$16.0 $7.8 $6.7 
Other information
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from finance leases$6.4 $1.8 $0.8 
Operating cash flows from operating leases7.5 7.1 6.8 
Financing cash flows from finance leases0.9 — — 
Non-cash activities
Right of use assets obtained in exchange for finance lease liabilities (4)
$63.8 $153.2 $32.8 
Right of use assets obtained in exchange for operating lease liabilities43.5 2.6 18.3 
Weighted-average remaining lease term – finance leases49.6 years50.2 years49.4 years
Weighted-average remaining lease term – operating leases35.8 years25.1 years22.4 years
Weighted-average discount rate – finance lease (5)
6.0 %5.9 %5.3 %
Weighted average discount rate – operating leases (5)
6.3 %5.9 %5.8 %

(1)    Amortization of right of use assets was included as a component of depreciation and amortization expense.

(2)    Interest on lease liabilities was included as a component of interest expense.

(3)    Operating and short-term lease expense were included as a component of other operation and maintenance expense.

(4)    Amounts are net of any reductions to right of use assets and finance lease liabilities resulting from remeasurements.
(5)    Because our leases do not provide an implicit rate of return, we used an estimate of the fully collateralized incremental borrowing rates based upon information available for similarly rated companies in determining the present value of lease payments.
Schedule of finance and operating lease right of use assets and obligations
The following table summarizes our finance and operating lease right of use assets and obligations at December 31:
(in millions)20252024Balance Sheet Location
Right of use assets
Operating lease right of use assets, net$69.5 $32.1 Other long-term assets
Finance lease right of use assets, net
Land leases – utility solar generation$291.5 $235.8 
Land leases –non-utility energy infrastructure solar generation42.3 43.5 
Other1.7 2.0 
Total finance lease right of use assets, net (1)
$335.5 $281.3 Property, plant, and equipment, net
Lease obligations
Current operating lease liabilities$3.1 $4.3 Other current liabilities
Long-term operating lease liabilities$73.0 $37.5 Other long-term liabilities
Current finance lease liabilities
Other$0.2 $0.2 Other current liabilities
Long-term finance lease liabilities
Land leases – utility solar generation$327.3 $257.9 
Land leases –non-utility energy infrastructure solar generation43.3 43.8 
Other1.4 1.6 
Total long-term finance lease liabilities$372.0 $303.3 Finance lease obligations

(1)    Amounts are net of accumulated amortization of $16.3 million and $10.0 million at December 31, 2025 and 2024, respectively.
Schedule of future minimum lease payments for operating and finance leases
Future minimum lease payments under our operating and finance leases and the present value of our net minimum lease payments as of December 31, 2025, were as follows:
(in millions)Total Operating LeasesLand Leases - Utility Solar GenerationLand Leases - Non-Utility Energy Infrastructure Solar GenerationOtherTotal Finance Leases
2026$7.0 $9.5 $2.2 $0.3 $12.0 
20276.3 13.8 2.3 0.3 16.4 
20285.2 15.9 2.3 0.1 18.3 
20295.2 16.2 2.3 0.1 18.6 
20305.0 16.6 2.4 0.1 19.1 
Thereafter208.2 1,221.0 156.6 2.5 1,380.1 
Total minimum lease payments236.9 1,293.0 168.1 3.4 1,464.5 
Less: Interest(160.8)(965.7)(124.8)(1.8)(1,092.3)
Present value of minimum lease payments76.1 327.3 43.3 1.6 372.2 
Less: Short-term lease liabilities(3.1)— — (0.2)(0.2)
Long-term lease liabilities$73.0 $327.3 $43.3 $1.4 $372.0 
v3.25.4
Income Taxes (Tables)
12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Components of income tax expense
The following table is a summary of the components of income tax expense for the years ended December 31:
(in millions)202520242023
Current tax expense (benefit)
Federal$(242.5)$(178.5)$(36.7)
State(8.0)(128.5)21.9 
Deferred tax expense, net
Federal240.9 386.2 130.1 
State135.6 152.5 99.8 
ITCs, net(8.0)(9.7)(10.5)
Total income tax expense$118.0 $222.0 $204.6 
Schedule of statutory rate reconciliation
The provision for income taxes for each of the years ended December 31 differs from the amount of income tax determined by applying the applicable United States statutory federal income tax rate to income before income taxes as a result of the following:
202520242023
(in millions)AmountEffective Tax RateAmountEffective Tax RateAmountEffective Tax Rate
Income before income taxes
$1,673.5 $1,746.3 $1,536.3 
US federal statutory income tax rate
$351.9 21.0 %$367.3 21.0 %$322.6 21.0 %
State and local income taxes net of federal tax effect (1)
101.2 6.0 %108.0 6.2 %94.3 6.1 %
Tax credits
PTCs, net (2)
(261.3)(15.6)%(200.1)(11.5)%(168.2)(10.9)%
Other(8.2)(0.5)%(10.0)(0.6)%(10.9)(0.7)%
Nontaxable or nondeductible items
AFUDC-Equity (3)
(21.0)(1.3)%(12.6)(0.7)%(12.4)(0.8)%
Other11.0 0.7 %4.0 0.2 %4.4 0.2 %
Changes in unrecognized tax benefits
(2.0)(0.1)%(0.4)— %(1.8)(0.1)%
Other adjustments
Federal excess deferred tax amortization (4)
(43.0)(2.6)%(36.7)(2.1)%(37.6)(2.4)%
Other, net(10.6)(0.5)%2.5 0.2 %14.2 0.9 %
Total income tax expense$118.0 7.1 %$222.0 12.7 %$204.6 13.3 %

(1)    State taxes in Wisconsin made up the majority of the tax effect in this category.

(2)    PTCs are an inflation adjusted US federal income tax credit for each kilowatt hour of electricity generated by certain renewable energy projects.

(3)    AFUDC-Equity represents the cost of capital (i.e. ROE) that is added to the construction cost of an asset while it is being built. The tax benefit for regulated utilities from AFUDC-Equity is a regulatory gross-up to allow the recovery of income taxes on the equity portion of construction costs, even though it is not a tax deductible expense.

(4)    The Tax Legislation required our regulated utilities to remeasure their deferred income taxes and we began to amortize the resulting excess deferred income taxes beginning in 2018, in accordance with normalization requirements. The decrease in income tax expense related to the amortization of the deferred tax benefits is offset by a decrease in revenue as the benefits are returned to customers, resulting in no impact on net income.
Components of deferred income taxes
The components of deferred income taxes as of December 31 were as follows:
(in millions)20252024
Deferred tax assets
Tax gross up – regulatory items$416.9 $420.1 
Future tax benefits240.9 165.4 
Deferred revenues76.8 76.0 
Other206.1 167.9 
Total deferred tax assets940.7 829.4 
Valuation allowance(1.1)(1.1)
Net deferred tax assets$939.6 $828.3 
Deferred tax liabilities
Property-related$5,041.5 $4,545.2 
Investment in affiliates1,143.6 1,103.9 
Employee benefits and compensation229.2 231.4 
Deferred costs – plant retirements178.0 194.3 
Other239.0 268.2 
Total deferred tax liabilities6,831.3 6,343.0 
Deferred tax liability, net$5,891.7 $5,514.7 
Components of deferred tax assets associated with federal and state tax benefit carryforwards
The components of net deferred tax assets associated with federal and state tax benefit carryforwards as of December 31, 2025 and 2024 are summarized in the tables below:
2025 (in millions)
Gross ValueDeferred Tax EffectValuation AllowanceEarliest Year of Expiration
Future tax benefits as of December 31, 2025
Federal tax credit$ $206.5 $ 2042
State net operating loss685.6 34.1 (1.1)2032
Other state benefits 0.3  2029
Balance as of December 31, 2025
$685.6 $240.9 $(1.1)

2024 (in millions)
Gross ValueDeferred Tax EffectValuation AllowanceEarliest Year of Expiration
Future tax benefits as of December 31, 2024
Federal tax credit$— $157.9 $— 2042
State net operating loss107.5 7.2 (1.1)2032
Other state benefits— 0.3 — 2028
Balance as of December 31, 2024
$107.5 $165.4 $(1.1)
Schedule of unrecognized tax benefits roll forward
A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:
(in millions)202520242023
Balance as of January 1$4.4 $4.6 $6.3 
Additions for tax positions of prior years0.1 — 0.2 
Reductions for tax positions of prior years(1.5)(0.2)(1.9)
Balance as of December 31$3.0 $4.4 $4.6 
Roll forward of interest accrued on unrecognized tax benefits
Interest accrued related to unrecognized tax benefits is as follows:
(in millions)202520242023
Balance as of January 1$0.9 $0.6 $0.5 
Interest expense (income) related to unrecognized tax benefits(0.6)0.3 0.1 
Balance as of December 31$0.3 $0.9 $0.6 
Summary of income tax examinations As of December 31, 2025, with a few exceptions, we were subject to examination by federal and state or local tax authorities for the 2021 through 2025 tax years in our major operating jurisdictions as follows:
JurisdictionYears
Federal
2022–2025
Illinois
2021–2025
Michigan
2021–2025
Minnesota
2021–2025
Wisconsin
2021–2025
Schedule of income taxes paid (received) by jurisdication
The table below is a summary of income taxes paid (received) by jurisdiction for the years ended December 31:
(in millions)202520242023
Federal
$(256.3)
(1)
$(265.0)
(2)
$(75.0)
(3)
State
(25.0)0.8 16.1 
Total income taxes received, net
$(281.3)$(264.2)$(58.9)

(1)    Includes $256.3 million related to 2025 and 2024 PTCs that were sold to third parties.

(2)    Includes $269.1 million related to 2024 and 2023 PTCs that were sold to third parties.

(3)    Includes $75.0 million related to 2023 PTCs that were sold to third parties.

Income taxes received or paid (net of refunds) exceeded 5 percent of total income taxes received or paid (net of refunds) in the following jurisdiction:
(in millions)202520242023
Wisconsin
$(25.0)$— 
(1)
$12.0 

(1)    Jurisdiction below the threshold for the period presented.
v3.25.4
Fair Value Measurements (Tables)
12 Months Ended
Dec. 31, 2025
Fair Value Disclosures [Abstract]  
Schedule of fair value of assets and liabilities measured on a recurring basis categorized by level within the fair value hierarchy
The following tables summarize our financial assets and liabilities that were accounted for at fair value on a recurring basis, categorized by level within the fair value hierarchy:
December 31, 2025
(in millions)Level 1Level 2Level 3Total
Derivative assets
Natural gas contracts$1.5 $18.3 $ $19.8 
FTRs and TCRs  6.5 6.5 
Total derivative assets$1.5 $18.3 $6.5 $26.3 
Investments held in rabbi trust $42.0 $ $ $42.0 
Derivative liabilities
Natural gas contracts$23.3 $8.4 $ $31.7 
FTRs and TCRs  0.8 0.8 
Total derivative liabilities$23.3 $8.4 $0.8 $32.5 

December 31, 2024
(in millions)Level 1Level 2Level 3Total
Derivative assets
Natural gas contracts$19.6 $13.7 $— $33.3 
FTRs and TCRs— — 7.8 7.8 
Total derivative assets$19.6 $13.7 $7.8 $41.1 
Investments held in rabbi trust $52.1 $— $— $52.1 
Derivative liabilities
Natural gas contracts$7.1 $6.8 $— $13.9 
Reconciliation of changes in fair value of items categorized as level 3 measurements
The following table summarizes the changes to derivatives classified as Level 3 in the fair value hierarchy at December 31:
(in millions)202520242023
Balance at the beginning of the period$7.8 $7.2 $7.8 
Purchases23.7 28.7 21.0 
Net realized and unrealized losses included in earnings (1)
 (0.7)(0.5)
Sales(1.0)— — 
Settlements(24.8)(27.4)(21.1)
Balance at the end of the period$5.7 $7.8 $7.2 
Net unrealized gains included in earnings attributable to Level 3 derivatives held at the end of the reporting period (1)
$0.1 $— $0.5 

(1)    Amounts relate to FTRs and TCRs included in our non-utility energy infrastructure segment. These net realized and unrealized gains and losses are recorded in operating revenues on our income statements.
Schedule of carrying value and fair value of financial instruments not recorded at fair value
The following table shows the financial instruments included on our balance sheets that are not recorded at fair value at December 31:
20252024
(in millions)Carrying AmountFair ValueCarrying AmountFair Value
Preferred stock of subsidiary$30.4 $21.2 $30.4 $21.2 
Long-term debt, including current portion20,017.5 19,609.1 18,907.1 17,840.8 
v3.25.4
Derivative Instruments (Tables)
12 Months Ended
Dec. 31, 2025
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Schedule of derivative assets and liabilities The following table shows our derivative assets and derivative liabilities. None of the derivatives shown below were designated as hedging instruments.
December 31, 2025December 31, 2024
(in millions)Derivative
Assets
Derivative
Liabilities
Derivative
Assets
Derivative
Liabilities
Current
Natural gas contracts$19.7 $30.0 $29.2 $13.9 
FTRs and TCRs6.5 0.8 7.8 — 
Total current26.2 30.8 37.0 13.9 
Long-term
Natural gas contracts0.1 1.7 4.1 — 
Total$26.3 $32.5 $41.1 $13.9 
Schedule of estimated notional volumes and realized gains (losses) Our realized gains and losses and the estimated notional volumes related to these settlements were as follows for the years ended:
December 31, 2025December 31, 2024December 31, 2023
(in millions)VolumesGains (Losses)VolumesGains (Losses)VolumesGains (Losses)
Natural gas contracts
202.4 Dth
$(19.2)
206.3 Dth
$(127.8)
198.0 Dth
$(259.1)
FTRs and TCRs
Regulated utility operations
26.3 MWh
18.9 
28.4 MWh
8.3 
29.3 MWh
27.4 
Non-utility operations
0.7 MWh
(0.1)
1.3 MWh
(0.1)
0.9 MWh
(1.5)
Total$(0.4)$(119.6)$(233.2)
Schedule of net derivative instruments
The following table shows derivative assets and derivative liabilities if derivative instruments by counterparty were presented net on our balance sheets:
December 31, 2025December 31, 2024
(in millions)Derivative
Assets
Derivative
Liabilities
Derivative
Assets
Derivative
Liabilities
Gross amount recognized on the balance sheet$26.3 $32.5 $41.1 $13.9 
Gross amount not offset on the balance sheet (2.0)(23.8)
(1)
(11.5)
(2)
(7.3)
Net amount$24.3 $8.7 $29.6 $6.6 

(1)    Includes cash collateral posted of $21.8 million.

(2)    Includes cash collateral received of $4.2 million.
v3.25.4
Guarantees (Tables)
12 Months Ended
Dec. 31, 2025
Guarantees [Abstract]  
Schedule of outstanding guarantees
The following table shows our outstanding guarantees:
Total Amounts Committed at December 31, 2025Expiration
(in millions)
Less Than 1 Year1 to 3 YearsOver 3 Years
Standby letters of credit (1)
$188.2 $30.7 $30.2 $127.3 
Surety bonds (2)
46.5 46.4 0.1 — 
Other guarantees (3)
9.6 — — 9.6 
Total guarantees$244.3 $77.1 $30.3 $136.9 

(1)    At our request or the request of our subsidiaries, financial institutions have issued standby letters of credit for the benefit of third parties that have extended credit to our subsidiaries. These amounts are not reflected on our balance sheets.

(2)    Primarily for environmental remediation, workers compensation self-insurance programs, and obtaining various licenses, permits, and rights-of-way. These amounts are not reflected on our balance sheets.

(3)    Related to workers compensation coverage for which a liability was recorded on our balance sheets.
v3.25.4
Employee Benefits (Tables)
12 Months Ended
Dec. 31, 2025
Retirement Benefits [Abstract]  
Reconciliation of the changes in the plans' benefit obligations and fair value of assets
The following tables provide a reconciliation of the changes in our plans' benefit obligations and fair value of assets:
Pension BenefitsOPEB Benefits
(in millions)2025202420252024
Change in benefit obligation
Obligation at January 1$2,209.2 $2,352.4 $460.9 $448.1 
Service cost20.8 24.2 11.3 10.9 
Interest cost118.6 116.6 25.7 22.7 
Participant contributions — 11.5 11.2 
Plan amendments — (0.4)— 
Actuarial (gain) loss8.2 (99.6)28.3 6.9 
Benefit payments(193.7)(184.4)(46.8)(41.7)
Federal subsidy on benefits paidN/AN/A1.4 1.4 
Transfer — 1.5 1.4 
Obligation at December 31$2,163.1 $2,209.2 $493.4 $460.9 
Change in fair value of plan assets
Fair value at January 1$2,624.3 $2,665.8 $850.0 $829.6 
Actual return on plan assets221.6 129.8 87.9 49.5 
Employer contributions net of plan transfer
11.8 13.1 1.9 1.4 
Participant contributions — 11.5 11.2 
Benefit payments(193.7)(184.4)(46.8)(41.7)
Fair value at December 31$2,664.0 $2,624.3 $904.5 $850.0 
Funded status at December 31$500.9 $415.1 $411.1 $389.1 
Amounts recognized on the balance sheets at December 31 related to the funded status of the benefit plans
The amounts recognized on our balance sheets at December 31 related to the funded status of the benefit plans were as follows:
Pension BenefitsOPEB Benefits
(in millions)2025202420252024
Pension and OPEB assets$646.3 $562.4 $436.1 $406.1 
Other long-term liabilities145.4 147.3 25.0 17.0 
Total net assets$500.9 $415.1 $411.1 $389.1 
Defined Benefit Plan Disclosure [Line Items]  
Amounts that had not yet been recognized in the entity's net periodic benefit cost
The following table shows the amounts that had not yet been recognized in our net periodic benefit cost (credit) as of December 31:
Pension BenefitsOPEB Benefits
(in millions)2025202420252024
Pre-tax accumulated other comprehensive income (loss) (1)
Net actuarial loss (gain)$11.6 $12.3 $(1.0)$(1.1)
Net regulatory assets (liabilities) (2)
Net actuarial loss (gain)$501.1 $578.7 $(146.1)$(148.8)
Prior service credits(2.0)(2.1)(8.4)(15.8)
Total$499.1 $576.6 $(154.5)$(164.6)

(1)    Amounts related to the nonregulated entities are included in accumulated other comprehensive loss.

(2)    Amounts related to the utilities and WBS are recorded as net regulatory assets or liabilities.
Schedule of the components of net periodic benefit cost
The components of net periodic benefit cost (credit) (including amounts capitalized to our balance sheets) for the years ended December 31 were as follows:
Pension BenefitsOPEB Benefits
(in millions)202520242023202520242023
Service cost$20.8 $24.2 $24.0 $11.3 $10.9 $9.8 
Interest cost118.6 116.6 122.3 25.7 22.7 21.6 
Expected return on plan assets(175.1)(182.1)(187.4)(54.3)(52.7)(53.0)
Plan settlement(1.2)4.0 1.3  — — 
Amortization of prior service cost (credit)(0.1)(0.1)— (7.8)(13.5)(14.8)
Amortization of net actuarial loss (gain)41.1 59.5 33.0 (8.2)(7.6)(12.3)
Net periodic benefit cost (credit)$4.1 $22.1 $(6.8)$(33.3)$(40.2)$(48.7)
Weighted-average assumptions used to determine benefit obligations and net periodic benefit cost for the plans
The weighted-average assumptions used to determine the benefit obligations for the plans were as follows for the years ended December 31:
Pension BenefitsOPEB Benefits
2025202420252024
Discount rate5.50%5.69%5.54%5.71%
Rate of compensation increase4.00%4.00%N/AN/A
Interest credit rate4.83%4.85%N/AN/A
Assumed medical cost trend rate (Pre 65)N/AN/A8.00%7.00%
Ultimate trend rate (Pre 65)N/AN/A5.00%5.00%
Year ultimate trend rate is reached (Pre 65)N/AN/A20322033
Assumed medical cost trend rate (Post 65)N/AN/A9.92%6.10%
Ultimate trend rate (Post 65)N/AN/A5.00%5.00%
Year ultimate trend rate is reached (Post 65)N/AN/A20342030

The weighted-average assumptions used to determine the net periodic benefit cost for the plans were as follows for the years ended December 31:
Pension Benefits
202520242023
Discount rate5.69%5.18%5.49%
Expected return on plan assets6.61%6.61%6.62%
Rate of compensation increase4.00%4.00%4.00%
Interest credit rate4.85%4.84%4.62%

OPEB Benefits
202520242023
Discount rate5.71%5.16%5.50%
Expected return on plan assets6.50%6.50%6.50%
Assumed medical cost trend rate (Pre 65)7.00%6.25%6.50%
Ultimate trend rate (Pre 65)5.00%5.00%5.00%
Year ultimate trend rate is reached (Pre 65)203320312031
Assumed medical cost trend rate (Post 65)6.10%6.39%6.00%
Ultimate trend rate (Post 65)5.00%5.00%5.00%
Year ultimate trend rate is reached (Post 65)203020302031
Investments recorded at fair value, by asset class
The following tables provide the fair values of our investments by asset class:
December 31, 2025
Pension Plan AssetsOPEB Assets
(in millions)Level 1Level 2Level 3TotalLevel 1Level 2Level 3Total
Asset Class
Equity securities:
United States equity$160.8 $ $ $160.8 $97.3 $ $ $97.3 
International equity173.7   173.7 100.8   100.8 
Fixed income securities: (1)
United States bonds 933.5 1.4 934.9 110.6 219.3 0.1 330.0 
International bonds 63.5  63.5  7.7  7.7 
$334.5 $997.0 $1.4 $1,332.9 $308.7 $227.0 $0.1 $535.8 
Investments measured at net asset value:
Equity securities412.6 206.0 
Fixed income securities127.6 55.3 
Other790.9 107.4 
Total$2,664.0 $904.5 

(1)    This category represents investment grade bonds of United States and foreign issuers denominated in United States dollars from diverse industries.
December 31, 2024
Pension Plan AssetsOPEB Assets
(in millions)Level 1Level 2Level 3TotalLevel 1Level 2Level 3Total
Asset Class
Equity securities:
United States equity$168.4 $— $— $168.4 $93.8 $— $— $93.8 
International equity158.2 — — 158.2 86.4 — — 86.4 
Fixed income securities: (1)
United States bonds— 880.1 — 880.1 99.0 205.6 — 304.6 
International bonds— 81.6 — 81.6 — 11.2 — 11.2 
$326.6 $961.7 $— $1,288.3 $279.2 $216.8 $— $496.0 
Investments measured at net asset value:
Equity securities414.9 190.4 
Fixed income securities126.0 51.8 
Other795.1 111.8 
Total$2,624.3 $850.0 

(1)    This category represents investment grade bonds of United States and foreign issuers denominated in United States dollars from diverse industries.
Reconciliation of level 3 changes in fair values
The following tables set forth a reconciliation of changes in fair values of pension and OPEB plan assets categorized as Level 3 in the fair value hierarchy:
United States Bonds
(in millions)PensionOPEB
Beginning balance at January 1, 2025
$ $ 
Purchases1.4 0.1 
Ending balance at December 31, 2025$1.4 $0.1 
Schedule of expected future benefit payments
The following table shows the payments, reflecting expected future service, that we expect to make for pension and OPEB over the next 10 years:
(in millions)Pension BenefitsOPEB Benefits
2026$213.5 $35.5 
2027203.1 37.6 
2028193.5 38.7 
2029187.5 39.5 
2030182.1 39.8 
2031-2035801.3 197.8 
Pension Benefits  
Defined Benefit Plan Disclosure [Line Items]  
Information for pension or OPEB plans with an accumulated benefit obligation in excess of plan assets
The following table shows information for pension plans with an accumulated benefit obligation in excess of plan assets. Amounts presented are as of December 31:
(in millions)20252024
Accumulated benefit obligation$283.0 $286.0 
Fair value of plan assets141.7 143.2 
Information for pension plans with a projected benefit obligation in excess of plan assets
The following table shows information for pension plans with a projected benefit obligation in excess of plan assets. Amounts presented are as of December 31:
(in millions)20252024
Projected benefit obligation$287.1 $290.5 
Fair value of plan assets141.7 143.2 
OPEB Benefits  
Defined Benefit Plan Disclosure [Line Items]  
Information for pension or OPEB plans with an accumulated benefit obligation in excess of plan assets
The following table shows information for OPEB plans with an accumulated benefit obligation in excess of plan assets. Amounts presented are as of December 31:
(in millions)20252024
Accumulated benefit obligation$205.5 $194.0 
Fair value of plan assets180.5 177.0 
v3.25.4
Investment in Transmission Affiliates (Tables)
12 Months Ended
Dec. 31, 2025
Equity Method Investments and Joint Ventures [Abstract]  
Schedule of changes in our investments in ATC and ATC Holdco The following tables provide a reconciliation of the changes in our investments in ATC and ATC Holdco:
2025
(in millions)ATCATC HoldcoTotal
Balance at January 1$2,085.1 $23.8 $2,108.9 
Add: Earnings from equity method investment209.7 6.1 215.8 
Add: Capital contributions142.4  142.4 
Less: Distributions180.2 6.4 186.6 
Less: Other0.1  0.1 
Balance at December 31$2,256.9 $23.5 $2,280.4 
2024
(in millions)ATCATC HoldcoTotal
Balance at January 1$1,980.8 $25.1 $2,005.9 
Add: Earnings from equity method investment205.4 2.1 207.5 
Add: Capital contributions45.5 — 45.5 
Less: Distributions146.7 3.4 150.1 
Add: Other0.1 — 0.1 
Balance at December 31$2,085.1 $23.8 $2,108.9 

2023
(in millions)ATCATC HoldcoTotal
Balance at January 1$1,884.6 $24.6 $1,909.2 
Add: Earnings from equity method investment175.1 2.4 177.5 
Add: Capital contributions63.7 — 63.7 
Less: Distributions142.6 1.9 144.5 
Balance at December 31$1,980.8 $25.1 $2,005.9 
Schedule of significant related party transactions with ATC
The following table summarizes our significant related party transactions with ATC during the years ended December 31:
(in millions)202520242023
Charges to ATC for services and construction$20.2 $21.6 $17.4 
Charges from ATC for network transmission services466.9 413.3 377.5 
Refund from ATC related to FERC ROE orders
5.2 — — 
Schedule of receivables and payables for services provided to or received from ATC
As of December 31, 2025 and 2024, our balance sheets included the following receivables and payables for services provided to or received from ATC:
(in millions)20252024
Accounts receivable for services provided to ATC$1.6 $1.4 
Accounts payable for services received from ATC38.4 34.4 
Amounts due from ATC for transmission infrastructure upgrades (1)
32.2 54.5 
(1)    The transmission infrastructure upgrades were primarily related to the construction of WE's, WPS's, and UMERC's renewable energy projects.
Schedule of summarized income statement data for ATC
Summarized financial data for ATC is included in the tables below:
Year Ended December 31
(in millions)202520242023
Income statement data
Operating revenues$975.0 $911.3 $818.9 
Operating expenses472.6 442.4 407.6 
Other expense, net165.8 137.7 131.7 
Net income$336.6 $331.2 $279.6 
Schedule of summarized balance sheet data for ATC
(in millions)December 31, 2025December 31, 2024
Balance sheet data
Current assets$137.5 $126.6 
Noncurrent assets7,590.8 6,792.6 
Total assets$7,728.3 $6,919.2 
Current liabilities$839.8 $482.4 
Long-term debt3,156.3 3,083.4 
Other noncurrent liabilities638.9 545.0 
Members' equity3,093.3 2,808.4 
Total liabilities and members' equity$7,728.3 $6,919.2 
v3.25.4
Segment Information (Tables)
12 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Schedule of information related to our reportable segments
The following tables show summarized financial information related to our reportable segments for the years ended December 31, 2025, 2024, and 2023.
 Utility Operations  
2025 (in millions)
WisconsinIllinoisOther States
Total Utility Operations
Electric TransmissionNon-Utility Energy Infrastructure
Corporate and Other
Reconciling Eliminations
WEC Energy Group Consolidated
External revenues $7,295.5 $1,683.6 $527.5 $9,506.6 $ $293.5 $ $ $9,800.1 
Intersegment revenues     476.7  (476.7) 
Fuel and purchased power
1,674.9   1,674.9     1,674.9 
Cost of natural gas sold
871.5 508.0 246.3 1,625.8  9.6  (44.5)1,590.9 
Other operation and maintenance1,737.9 482.2 104.6 2,324.7  95.5 (10.2)(9.2)2,400.8 
Impairments related to Illinois segment 130.0  130.0     130.0 
Depreciation and amortization1,008.1 259.7 49.8 1,317.6  240.2 21.6 (100.9)1,478.5 
Property and revenue taxes
178.7 55.5 26.2 260.4  19.6 0.1  280.1 
Equity in earnings of transmission affiliates    215.8    215.8 
Other income, net (1)
96.5 8.6 0.4 105.5  2.8 30.6 (31.0)107.9 
Interest expense638.7 88.9 19.2 746.8 19.3 123.1 359.0 (353.1)895.1 
Income tax expense (benefit)226.2 45.8 21.0 293.0 48.9 (122.9)(101.0) 118.0 
Preferred stock dividends of subsidiary
1.2   1.2     1.2 
Net loss attributed to noncontrolling interests
     3.2   3.2 
Net income (loss) attributed to common shareholders$1,054.8 $122.1 $60.8 $1,237.7 $147.6 $411.1 $(238.9)$ $1,557.5 
Other Segment Disclosures
Capital expenditures and asset acquisitions$3,860.1 $306.1 $112.5 $4,278.7 $ $504.7 $20.8 $ $4,804.2 
Equity method investments
17.8   17.8 2,280.4  55.7  2,353.9 
Total assets (2)
33,984.7 8,167.7 1,733.3 43,885.7 2,282.8 7,762.9 1,227.6 (3,640.7)51,518.3 

(1)Includes amounts that are not material for interest income and other equity earnings from investments other than from transmission affiliates.

(2)    Total assets at December 31, 2025 reflect an elimination of $2,594.8 million for all lease activity between We Power and WE.
Utility Operations  
2024 (in millions)
WisconsinIllinoisOther States
Total Utility Operations
Electric TransmissionNon-Utility Energy Infrastructure
Corporate and Other
Reconciling Eliminations
WEC Energy Group Consolidated
External revenues $6,330.5 $1,602.4 $449.8 $8,382.7 $— $217.2 $— $— $8,599.9 
Intersegment revenues— — — — — 474.1 — (474.1)— 
Fuel and purchased power
1,455.7 — — 1,455.7 — — — — 1,455.7 
Cost of natural gas sold
661.9 376.7 198.6 1,237.2 — 9.1 — (46.0)1,200.3 
Other operation and maintenance1,547.9 461.5 93.9 2,103.3 — 75.1 (11.3)(9.1)2,158.0 
Impairments related to Illinois segment— 12.1 — 12.1 — — — — 12.1 
Depreciation and amortization919.9 255.4 47.0 1,222.3 — 198.4 22.3 (88.5)1,354.5 
Property and revenue taxes
169.6 59.9 21.0 250.5 — 15.7 0.3 — 266.5 
Equity in earnings of transmission affiliates— — — — 207.5 — — — 207.5 
Other income, net (1)
146.6 7.6 0.3 154.5 — 1.0 54.4 (31.7)178.2 
Interest expense637.3 94.7 16.4 748.4 19.4 99.7 310.0 (362.2)815.3 
Gain on debt extinguishments
— — — — — — (23.1)— (23.1)
Income tax expense (benefit)220.5 97.6 18.7 336.8 47.1 (82.4)(79.5)— 222.0 
Preferred stock dividends of subsidiary
1.2 — — 1.2 — — — — 1.2 
Net loss attributed to noncontrolling interests
— — — — — 4.1 — — 4.1 
Net income (loss) attributed to common shareholders$863.1 $252.1 $54.5 $1,169.7 $141.0 $380.8 $(164.3)$— $1,527.2 
Other Segment Disclosures
Capital expenditures and asset acquisitions$2,347.1 $343.0 $118.3 $2,808.4 $— $945.8 $20.6 $— $3,774.8 
Equity method investments
15.7 — — 15.7 2,108.9 — 67.0 — 2,191.6 
Total assets (2)
30,622.7 8,168.8 1,646.0 40,437.5 2,126.0 7,316.0 1,037.3 (3,553.6)47,363.2 

(1)Includes amounts that are not material for interest income and other equity earnings from investments other than from transmission affiliates.

(2)    Total assets at December 31, 2024 reflect an elimination of $1,525.4 million for all lease activity between We Power and WE.
 Utility Operations  
2023 (in millions)
WisconsinIllinoisOther States
Total Utility Operations
Electric TransmissionNon-Utility Energy Infrastructure
Corporate and Other
Reconciling Eliminations
WEC Energy Group Consolidated
External revenues $6,625.9 $1,557.8 $519.1 $8,702.8 $— $190.1 $0.1 $— $8,893.0 
Intersegment revenues— — — — — 476.4 — (476.4)— 
Fuel and purchased power
1,615.9 — — 1,615.9 — — — — 1,615.9 
Cost of natural gas sold
894.7 443.0 277.2 1,614.9 — 20.5 — (60.1)1,575.3 
Other operation and maintenance1,531.3 397.9 94.5 2,023.7 — 80.1 5.8 (9.1)2,100.5 
Impairments related to Illinois segment— 178.9 — 178.9 — — — — 178.9 
Depreciation and amortization851.5 237.3 43.3 1,132.1 — 188.7 20.9 (77.5)1,264.2 
Property and revenue taxes
179.2 29.9 24.4 233.5 — 16.5 0.2 — 250.2 
Equity in earnings of transmission affiliates— — — — 177.5 — — — 177.5 
Other income, net (1)
137.6 6.7 0.6 144.9 — — 53.3 (20.5)177.7 
Interest expense601.0 88.9 15.9 705.8 19.4 94.3 258.1 (350.2)727.4 
Gain on debt extinguishments— — — — — — (0.5)— (0.5)
Income tax expense (benefit)237.4 48.6 16.3 302.3 39.0 (68.4)(68.3)— 204.6 
Preferred stock dividends of subsidiary1.2 — — 1.2 — — — — 1.2 
Net loss attributed to noncontrolling interests— — — — — 1.2 — — 1.2 
Net income (loss) attributed to common shareholders$851.3 $140.0 $48.1 $1,039.4 $119.1 $336.0 $(162.8)$— $1,331.7 
Other Segment Disclosures
Capital expenditures and asset acquisitions$2,134.4 $489.8 $103.5 $2,727.7 $— $754.4 $25.8 $— $3,507.9 
Equity method investments
14.4 — — 14.4 2,005.9 — 61.3 — 2,081.6 
Total assets (2)
28,527.3 7,970.2 1,571.5 38,069.0 2,006.0 6,404.7 1,100.1 (3,640.1)43,939.7 

(1)    Includes amounts that are not material for interest income and other equity earnings from investments other than from transmission affiliates.

(2)    Total assets at December 31, 2023 reflect an elimination of $1,630.6 million for all lease activity between We Power and WE.
v3.25.4
Variable Interest Entities (Tables)
12 Months Ended
Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Schedule of balance sheet impact of WEPCo Environmental Trust
The following table summarizes the impact of WEPCo Environmental Trust on our balance sheets:
(in millions)December 31, 2025December 31, 2024
Assets
Other current assets (restricted cash)$2.0 $1.5 
Regulatory assets67.5 76.5 
Other long-term assets (restricted cash)0.6 0.6 
Liabilities
Current portion of long-term debt9.3 9.2 
Accounts payable0.1 — 
Other current liabilities (accrued interest)0.1 0.1 
Long-term debt67.4 76.4 
v3.25.4
Commitments and Contingencies (Tables)
12 Months Ended
Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]  
Schedule of minimum future commitments related to purchase obligations
The following table shows our minimum future commitments related to these purchase obligations as of December 31, 2025, including those of our subsidiaries:
Payments Due By Period
(in millions)Date Contracts Extend ThroughTotal Amounts Committed20262027202820292030Later Years
Electric utility:
Nuclear2033$5,045.8 $681.6 $730.4 $782.6 $838.5 $898.5 $1,114.2 
Coal supply and transportation2028412.1 242.2 127.7 37.0 3.5 1.7 — 
Purchased power2063335.3 61.6 56.3 52.4 25.6 5.9 133.5 
Other204385.5 12.0 12.1 9.6 8.4 8.5 34.9 
Natural gas utility:
Supply and transportation20482,921.3 487.0 478.8 426.8 323.6 203.0 1,002.1 
Non-utility energy infrastructure:
Purchased power2055720.7 55.0 56.3 57.6 50.7 48.4 452.7 
Natural gas storage and transportation20484.6 3.9 — 0.1 — — 0.6 
Total$9,525.3 $1,543.3 $1,461.6 $1,366.1 $1,250.3 $1,166.0 $2,738.0 
Schedule of regulatory assets and reserves related to manufactured gas plant sites
We have established the following regulatory assets and reserves for manufactured gas plant sites as of December 31:
(in millions)20252024
Regulatory assets for environmental remediation costs$566.0 $570.1 
Reserves for future environmental remediation484.1 445.8 
v3.25.4
Supplemental Cash Flow Information (Tables)
12 Months Ended
Dec. 31, 2025
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]  
Schedule of supplemental cash flow information
The following table provides additional information regarding our statements of cash flows:
Year Ended December 31
(in millions)202520242023
Cash paid for interest, net of amount capitalized$858.5 $785.7 $653.4 
Cash received for income taxes, net
(281.3)(264.2)(58.9)
Significant non-cash investing and financing transactions:
Accounts payable related to construction costs232.0 285.7 171.3 
Common stock issued for stock-based compensation plans3.2 6.4 — 
Increase in receivables related to property damage insurance proceeds3.5 2.3 3.5 
Increase in receivables for corporate-owned life insurance proceeds 5.8 1.4 
Liabilities accrued for software licensing agreements21.1 0.2 — 
Reconciliation of cash, cash equivalents, and restricted cash The following table reconciles the cash, cash equivalents, and restricted cash amounts reported within the balance sheets at December 31 to the total of these amounts shown on the statements of cash flows:
(in millions)202520242023
Cash and cash equivalents$27.6 $9.8 $42.9 
Restricted cash included in other current assets9.1 5.3 70.1 
Restricted cash included in other long-term assets34.2 27.1 52.2 
Cash, cash equivalents, and restricted cash$70.9 $42.2 $165.2 
v3.25.4
Regulatory Environment (Tables) - Public Service Commission of Wisconsin
12 Months Ended
Dec. 31, 2025
2025 and 2026 Rates  
Public Utilities, General Disclosures  
Schedule of regulatory decisions The final written orders reflected the following:
WEWPSWG
2025 rate increase
Electric (1)
$144.0  million/4.2%$55.1  million/4.5%N/A
Gas$41.3  million/7.1%$14.9  million/3.8%$34.5  million/4.2%
Steam$1.5  million/5.0%N/AN/A
2026 rate increase (2)
Electric (1)
$169.5  million/4.5%$30.0  million/2.3%N/A
Gas$29.8  million/4.5%$13.5  million/3.1%$23.5  million/2.6%
ROE9.8%9.8%9.8%
Common equity component average on a financial basis53.0%53.0%53.0%

(1)    Amounts reflect the impact to our Wisconsin retail electric operations and include the incremental decrease resulting from updated fuel costs.

(2)    The 2026 rate increases are incremental to the previously authorized revenue plus the approved rate increases for 2025.
2024 Rate Case Re-Opener  
Public Utilities, General Disclosures  
Schedule of regulatory decisions The final orders reflected the following:
WEWPSWG
2024 incremental rate increases (decreases)
Electric (1)
$82.2  million/2.5%$(32.7) million/(2.6)%N/A
Gas$23.9  million/4.5%N/A$21.6  million/2.8%

(1)    Amounts reflect the impact to our Wisconsin retail electric operations and include any incremental increases (WE) or decreases (WPS) resulting from updated fuel costs.
2023 and 2024 Rates  
Public Utilities, General Disclosures  
Schedule of regulatory decisions The final orders reflected the following:
WEWPSWG
2023 base rate increase
Electric$283.5  million/9.1%$120.5  million/9.8%N/A
Gas$46.1  million/9.6%$26.4  million/7.1%$46.5  million/6.4%
Steam$7.6  million/35.3%N/AN/A
ROE9.8%9.8%9.8%
Common equity component average on a financial basis53.0%53.0%53.0%
v3.25.4
Other Income, Net (Tables)
12 Months Ended
Dec. 31, 2025
Other Income and Expenses [Abstract]  
Schedule of other income, net
Total other income, net was as follows for the years ended December 31:
(in millions)202520242023
AFUDC-Equity$99.8 $59.8 $59.1 
Gains from investments held in rabbi trust8.1 11.7 13.7 
Interest income5.9 17.2 3.9 
Non-service components of net periodic benefit costs2.7 83.7 97.7 
Earnings (losses) from equity method investments (1)
(10.4)4.7 (1.1)
Other, net1.8 1.1 4.4 
Other income, net$107.9 $178.2 $177.7 

(1)    Amounts do not include equity earnings of transmission affiliates as those earnings are shown as a separate line item on the income statements.
v3.25.4
Summary of Significant Accounting Policies Nature of Operations (Details)
customer in Millions
Dec. 31, 2025
customer
ATC  
Product Information  
Equity method investment, ownership interest (as a percent) 60.00%
ATC Holdco  
Product Information  
Equity method investment, ownership interest (as a percent) 75.00%
Electric  
Product Information  
Number of customers 1.7
Natural gas  
Product Information  
Number of customers 3.0
v3.25.4
Summary of Significant Accounting Policies Cash and Cash Equivalents (Details)
12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Maximum term of original maturity to classify instrument as cash equivalent 3 months
v3.25.4
Summary of Significant Accounting Policies Operating Revenues (Details)
$ in Millions
12 Months Ended
Dec. 31, 2025
USD ($)
performance_obligations
contract
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Electric      
Disaggregation of Operating Revenues      
Number of days payment is due 30 days    
Electric | Retail      
Disaggregation of Operating Revenues      
Number of performance obligations 1    
Percent fuel and purchased power costs can vary from the rate case approved costs before deferral is required 2.00%    
Electric | Wholesale      
Disaggregation of Operating Revenues      
Number of performance obligations 2    
Number of contracts | contract 1    
Natural gas      
Disaggregation of Operating Revenues      
Number of days payment is due 30 days    
Other non-utility revenues      
Disaggregation of Operating Revenues      
Number of days payment is due 30 days    
Appliance service repairs | Maximum      
Disaggregation of Operating Revenues      
Duration of contract for remaining performance obligations in contract 1 year    
We Power revenues      
Disaggregation of Operating Revenues      
Revenues amortized from deferred revenue during the period | $ $ 24.6 $ 24.3 $ 23.5
Bespoke resources current return      
Disaggregation of Operating Revenues      
Number of days payment is due 45 days    
v3.25.4
Summary of Significant Accounting Policies Materials, Supplies, and Inventories (Details)
$ in Millions
Dec. 31, 2025
USD ($)
$ / MMBTU
Dec. 31, 2024
USD ($)
$ / MMBTU
Accounting Policies [Abstract]    
Materials and supplies $ 416.4 $ 412.5
Natural gas in storage 292.5 300.2
Fossil fuel 94.5 100.5
Total $ 803.4 $ 813.2
LIFO Method Related Items [Abstract]    
Percentage of LIFO inventory 17.00% 18.00%
Excess of replacement or current costs over stated LIFO value $ 94.9 $ 77.9
Natural gas price benchmark | $ / MMBTU 3.36 3.10
v3.25.4
Summary of Significant Accounting Policies Property, Plant, and Equipment (Details)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
WECI Wind Generating Facility | Maximum      
Property, plant, and equipment      
Estimated useful life 30 years    
WECI Solar Generating Facility | Maximum      
Property, plant, and equipment      
Estimated useful life 35 years    
Software | Minimum      
Property, plant, and equipment      
Estimated useful life 3 years    
Software | Maximum      
Property, plant, and equipment      
Estimated useful life 15 years    
PWGS | Minimum      
Property, plant, and equipment      
Estimated useful life 10 years    
PWGS | Maximum      
Property, plant, and equipment      
Estimated useful life 45 years    
ERGS | Minimum      
Property, plant, and equipment      
Estimated useful life 10 years    
ERGS | Maximum      
Property, plant, and equipment      
Estimated useful life 55 years    
WE      
Property, plant, and equipment      
Annual utility composite depreciation rate (as a percent) 3.07% 3.03% 3.03%
WPS      
Property, plant, and equipment      
Annual utility composite depreciation rate (as a percent) 3.01% 2.92% 2.93%
WG      
Property, plant, and equipment      
Annual utility composite depreciation rate (as a percent) 2.45% 2.61% 2.61%
PGL      
Property, plant, and equipment      
Annual utility composite depreciation rate (as a percent) 3.34% 3.36% 3.13%
NSG      
Property, plant, and equipment      
Annual utility composite depreciation rate (as a percent) 2.49% 2.49% 2.46%
MERC      
Property, plant, and equipment      
Annual utility composite depreciation rate (as a percent) 2.62% 2.60% 2.60%
MGU      
Property, plant, and equipment      
Annual utility composite depreciation rate (as a percent) 2.87% 2.87% 2.73%
UMERC      
Property, plant, and equipment      
Annual utility composite depreciation rate (as a percent) 3.20% 3.01% 2.97%
v3.25.4
Summary of Significant Accounting Policies AFUDC (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Allowance for Funds Used During Construction      
AFUDC - Debt $ 39.0 $ 19.4 $ 19.5
AFUDC - Equity 99.8 59.8 59.1
WE      
Allowance for Funds Used During Construction      
AFUDC - Debt 29.8 14.6 13.0
AFUDC - Equity 78.9 46.0 41.0
WPS      
Allowance for Funds Used During Construction      
AFUDC - Debt 4.7 3.6 2.9
AFUDC - Equity 12.2 9.2 7.6
WG      
Allowance for Funds Used During Construction      
AFUDC - Debt 0.5 0.5 3.4
AFUDC - Equity 1.2 2.9 9.8
UMERC      
Allowance for Funds Used During Construction      
AFUDC - Debt 3.4 0.4 0.0
AFUDC - Equity 6.3 1.0 0.0
WBS      
Allowance for Funds Used During Construction      
AFUDC - Debt 0.2 0.1 0.1
AFUDC - Equity 0.5 0.3 0.4
Other      
Allowance for Funds Used During Construction      
AFUDC - Debt 0.4 0.2 0.1
AFUDC - Equity $ 0.7 $ 0.4 $ 0.3
Retail operations | WE      
Allowance for Funds Used During Construction      
Percentage of retail jurisdictional construction work in progress expenditures subject to AFUDC 50.00%    
Average AFUDC rate (as a percent) 8.65%    
Retail operations | WPS      
Allowance for Funds Used During Construction      
Percentage of retail jurisdictional construction work in progress expenditures subject to AFUDC 50.00%    
Average AFUDC rate (as a percent) 7.82%    
Retail operations | WG      
Allowance for Funds Used During Construction      
Percentage of retail jurisdictional construction work in progress expenditures subject to AFUDC 50.00%    
Average AFUDC rate (as a percent) 8.54%    
Retail operations | UMERC      
Allowance for Funds Used During Construction      
Percentage of retail jurisdictional construction work in progress expenditures subject to AFUDC 50.00%    
Average AFUDC rate (as a percent) 6.40%    
Retail operations | WBS      
Allowance for Funds Used During Construction      
Percentage of retail jurisdictional construction work in progress expenditures subject to AFUDC 50.00%    
Average AFUDC rate (as a percent) 7.82%    
Wholesale operations | WE      
Allowance for Funds Used During Construction      
Average AFUDC rate (as a percent) 7.51%    
Wholesale operations | WPS      
Allowance for Funds Used During Construction      
Average AFUDC rate (as a percent) 6.62%    
v3.25.4
Summary of Significant Accounting Policies Cloud Computing Hosting Arrangements that are Service Contracts (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Accounting Policies [Abstract]    
Capitalized implementation costs, gross $ 27.0 $ 17.0
Capitalized implementation costs, accumulated amortization $ 5.8 $ 4.1
v3.25.4
Summary of Significant Accounting Policies Asset Impairment (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Accounting Policies [Abstract]      
Impairment losses for indefinite-lived intangible assets $ 0.0 $ 0.0 $ 0.0
Impaired Long-Lived Assets Held and Used [Line Items]      
Impairments related to Illinois segment 130.0 12.1 178.9
Impairment losses $ 145.9 $ 12.1 $ 178.9
Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration] Other operation and maintenance Other operation and maintenance Other operation and maintenance
Illinois      
Impaired Long-Lived Assets Held and Used [Line Items]      
Impairments related to Illinois segment $ 130.0 $ 12.1 $ 178.9
Non-Utility Energy Infrastructure      
Impaired Long-Lived Assets Held and Used [Line Items]      
Impairment losses $ 15.9 $ 0.0 $ 0.0
v3.25.4
Summary of Significant Accounting Policies Stock-Based Compensation (Details) - $ / shares
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
May 06, 2021
Share-based Compensation Arrangement by Share-based Payment Award        
Number of shares authorized for issuance       9,000,000.0
Stock options        
Share-based Compensation Arrangement by Share-based Payment Award        
Vesting period (in years) 3 years      
Minimum exercise price of stock option as a percent of common stock fair value on the grant date 100.00%      
Period after the grant date during which stock options can't be exercised (in months) 6 months      
Maximum term of awards (in years) 10 years      
Stock options granted (in shares) 231,024 294,990 257,780  
Estimated weighted-average fair value per stock option (in dollars per share) $ 18.23 $ 16.19 $ 19.58  
Risk-free interest rate, minimum (as a percent) 4.20% 3.90% 3.80%  
Risk-free interest rate, maximum (as a percent) 4.60% 5.40% 4.80%  
Dividend yield (as a percent) 4.10% 3.80% 3.20%  
Expected volatility (as a percent) 22.00% 22.00% 22.00%  
Expected life (in years) 8 years 3 months 18 days 8 years 4 months 24 days 8 years 3 months 18 days  
Restricted stock | Employees        
Share-based Compensation Arrangement by Share-based Payment Award        
Vesting period (in years) 3 years      
Percentage to vest each year after grant date 33.00%      
Restricted stock | Directors        
Share-based Compensation Arrangement by Share-based Payment Award        
Vesting period (in years) 1 year      
Performance units        
Share-based Compensation Arrangement by Share-based Payment Award        
Vesting period (in years) 3 years      
Percentage of payout based on total shareholder return 55.00%      
Percentage of payout based on ROE 45.00%      
Maximum adjustment to payout ratio 25.00%      
Maximum payout ratio (as a percent) 200.00%      
v3.25.4
Summary of Significant Accounting Policies Earnings Per Share (Details) - shares
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Forward equity sales contract      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of earnings per share 58,533    
Stock options      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of earnings per share 0 66,870 1,716,286
Convertible Debt | WEC 3.375% Convertible Notes due June 1, 2028      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Dilutive shares 0    
Convertible Debt | WEC 4.375% Convertible Notes due June 1, 2027      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Dilutive shares   0  
Convertible Debt | WEC 4.375% Convertible Notes due June 1, 2029      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Dilutive shares   0  
v3.25.4
Summary of Significant Accounting Policies - Leases (Details)
Dec. 31, 2025
Accounting Policies [Abstract]  
Minimum lease term to recognize right of use asset and lease liabilities 1 year
v3.25.4
Summary of Significant Accounting Policies Customer Concentrations of Credit Risk (Details) - Customer Concentration Risk
12 Months Ended
Dec. 31, 2025
customer
Customer concentrations of credit risk  
Number of customers that account for more than 10% of revenues 0
Revenue Benchmark  
Customer concentrations of credit risk  
Concentration risk threshold percentage 10.00%
v3.25.4
Acquisitions - Hardin III (Details)
$ in Millions
1 Months Ended
Feb. 28, 2025
USD ($)
Feb. 28, 2025
USD ($)
Dec. 31, 2024
USD ($)
MW
Dec. 31, 2025
USD ($)
Feb. 24, 2025
USD ($)
Feb. 11, 2025
MW
Dec. 03, 2024
USD ($)
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest              
Net property, plant, and equipment     $ 34,645.4 $ 38,278.1      
Other current assets     121.9 119.8      
Other current liabilities     (4,841.9) (5,593.4)      
Other long-term liabilities     (29,719.4) (31,872.1)      
Noncontrolling interest     $ (376.5) $ (408.8)      
Hardin III | WECI              
Asset Acquisition              
Ownership interest in generating facility acquired           90.00%  
Capacity of generation unit | MW           250  
Total purchase price $ 406.1 $ 406.1          
Duration of offtake agreement for the sale of energy produced   15 years          
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest              
Net property, plant, and equipment         $ 526.5    
Other current assets         0.2    
Other current liabilities         (0.4)    
Other long-term liabilities         (75.1)    
Noncontrolling interest         $ (45.1)    
Total purchase price $ 406.1 $ 406.1          
Delilah I | WECI              
Asset Acquisition              
Ownership interest in generating facility acquired     90.00%        
Capacity of generation unit | MW     300        
Total purchase price     $ 462.5        
Duration of offtake agreement for the sale of energy produced     15 years        
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest              
Net property, plant, and equipment             $ 579.8
Other current assets             0.1
Other long-term liabilities             (78.3)
Noncontrolling interest             $ (51.5)
Total purchase price     $ 462.5        
v3.25.4
Acquisitions - Delilah (Details)
$ in Millions
1 Months Ended
Dec. 31, 2024
USD ($)
MW
Dec. 31, 2025
USD ($)
Dec. 03, 2024
USD ($)
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest      
Other current assets $ 121.9 $ 119.8  
Net property, plant, and equipment 34,645.4 38,278.1  
Other long-term assets 336.2 383.6  
Other long-term liabilities (29,719.4) (31,872.1)  
Noncontrolling interest $ (376.5) $ (408.8)  
Delilah I | WECI      
Asset Acquisition      
Ownership interest in generating facility acquired 90.00%    
Capacity of generation unit | MW 300    
Total purchase price $ 462.5    
Duration of offtake agreement for the sale of energy produced 15 years    
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest      
Other current assets     $ 0.1
Net property, plant, and equipment     579.8
Other long-term assets     12.4
Other long-term liabilities     (78.3)
Noncontrolling interest     $ (51.5)
Total purchase price $ 462.5    
v3.25.4
Acquisitions - Samson I (Details)
$ in Millions
1 Months Ended
Feb. 28, 2023
USD ($)
MW
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest      
Other current assets   $ 3,284.7 $ 2,911.7
Net property, plant, and equipment   38,278.1 34,645.4
Other long-term assets   383.6 336.2
Other current liabilities   (5,593.4) (4,841.9)
Other long-term liabilities   (31,872.1) (29,719.4)
Noncontrolling interest   $ (408.8) $ (376.5)
Samson I | WECI      
Asset Acquisition      
Ownership interest in generating facility acquired 80.00%    
Capacity of generation unit | MW 250    
Total purchase price $ 257.3    
Duration of offtake agreement for the sale of energy produced 15 years    
Additional ownership interest acquired 10.00%    
Additional acquisition purchase price $ 28.1    
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest      
Accounts receivable 0.5    
Other current assets 0.7    
Net property, plant, and equipment 497.2    
Other long-term assets 12.3    
Accounts payable (0.5)    
Other current liabilities (0.8)    
Other long-term liabilities (186.4)    
Noncontrolling interest (65.7)    
Total purchase price $ 257.3    
v3.25.4
Acquisitions - Maple Flats (Details)
$ in Millions
1 Months Ended
Nov. 30, 2024
USD ($)
MW
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest      
Net property, plant, and equipment   $ 38,278.1 $ 34,645.4
Other long-term assets   383.6 336.2
Other long-term liabilities   (31,872.1) (29,719.4)
Noncontrolling interest   $ (408.8) $ (376.5)
Maple Flats | WECI      
Asset Acquisition      
Ownership interest in generating facility acquired 90.00%    
Capacity of generation unit | MW 250    
Total purchase price $ 431.2    
Duration of offtake agreement for the sale of energy produced 15 years    
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest      
Net property, plant, and equipment $ 469.5    
Other long-term assets 44.5    
Other long-term liabilities (34.9)    
Noncontrolling interest (47.9)    
Total purchase price $ 431.2    
v3.25.4
Acquisitions - Sapphire Sky (Details)
$ in Millions
1 Months Ended
Feb. 28, 2023
USD ($)
MW
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest      
Net property, plant, and equipment   $ 38,278.1 $ 34,645.4
Other long-term assets   383.6 336.2
Other long-term liabilities   (31,872.1) (29,719.4)
Noncontrolling interest   $ (408.8) $ (376.5)
Sapphire Sky | WECI      
Asset Acquisition      
Ownership interest in generating facility acquired 90.00%    
Capacity of generation unit | MW 250    
Total purchase price $ 442.6    
Duration of offtake agreement for the sale of energy produced 12 years    
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest      
Accounts receivable $ 0.8    
Net property, plant, and equipment 642.6    
Other long-term assets 1.4    
Accounts payable (1.0)    
Other long-term liabilities (152.0)    
Noncontrolling interest (49.2)    
Total purchase price $ 442.6    
v3.25.4
Acquisitions - Whitetail (Details) - Whitetail Wind Energy Generating Facility
$ in Millions
1 Months Ended
Dec. 31, 2025
USD ($)
MW
WE  
Asset Acquisition  
Capacity of generation unit | MW 67.2
Joint plant ownership percentage 80.00%
Acquisition purchase price, expected $ 178.0
WPS  
Asset Acquisition  
Joint plant ownership percentage 10.00%
Acquisition purchase price, expected $ 22.0
v3.25.4
Acquisitions - West Riverside (Details) - West Riverside Energy Center - WE
$ in Millions
1 Months Ended
May 31, 2024
USD ($)
MW
Jun. 30, 2023
USD ($)
MW
Asset Acquisition    
Capacity of generation unit | MW 100 100
Total purchase price | $ $ 97.9 $ 95.3
Share of capacity (MW) | MW 200  
Joint plant ownership percentage 27.50%  
Asset Acquisition, Total Consideration Transferred | $ $ 193.2  
v3.25.4
Acquisitions - Red Barn (Details) - Red Barn Wind Park - WPS
$ in Millions
1 Months Ended
Apr. 30, 2023
USD ($)
MW
Asset Acquisition  
Capacity of generation unit | MW 82
Total purchase price | $ $ 145.9
v3.25.4
Acquisitions - Whitewater (Details) - Whitewater - WE and WPS
$ in Millions
1 Months Ended
Jan. 31, 2023
USD ($)
MW
Asset Acquisition  
Capacity of generation unit | MW 236.5
Total purchase price | $ $ 76.0
v3.25.4
Dispositions - WE (Details) - WE
$ in Millions
1 Months Ended
Jun. 30, 2023
USD ($)
a
Dispositions  
NumberofAcresSold | a 192
Proceeds from sale of real estate $ 23.0
Pre-tax gain on sale of real estate $ 22.2
v3.25.4
Operating Revenues - Disaggregation Of Operating Revenues by Segment (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Operating Revenues      
Operating revenues $ 9,800.1 $ 8,599.9 $ 8,893.0
Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 9,755.6 8,467.7 8,785.3
Other operating revenues      
Disaggregation of Operating Revenues      
Other operating revenues 44.5 132.2 107.7
Total regulated revenues | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 9,499.4 8,232.5 8,577.2
Electric | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 5,529.6 4,908.4 4,994.6
Natural gas | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 3,969.8 3,324.1 3,582.6
Natural gas | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 3,967.3 3,321.7 3,580.9
Other non-utility revenues | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 256.2 235.2 208.1
Reconciling Eliminations      
Disaggregation of Operating Revenues      
Operating revenues (476.7) (474.1) (476.4)
Reconciling Eliminations | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers (53.7) (55.1) (69.3)
Reconciling Eliminations | Other operating revenues      
Disaggregation of Operating Revenues      
Other operating revenues (423.0) (419.0) (407.1)
Reconciling Eliminations | Total regulated revenues | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers (44.5) (46.0) (60.2)
Reconciling Eliminations | Electric | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.0
Reconciling Eliminations | Natural gas | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers (44.5) (46.0) (60.2)
Reconciling Eliminations | Other non-utility revenues | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers (9.2) (9.1) (9.1)
Total Utility Operations | Operating segments      
Disaggregation of Operating Revenues      
Operating revenues 9,506.6 8,382.7 8,702.8
Total Utility Operations | Operating segments | Other operating revenues      
Disaggregation of Operating Revenues      
Other operating revenues (12.1) 132.2 107.7
Total Utility Operations | Operating segments | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 9,518.7 8,250.5 8,595.1
Total Utility Operations | Operating segments | Total regulated revenues | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 9,496.9 8,230.1 8,575.5
Total Utility Operations | Operating segments | Electric | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 5,529.6 4,908.4 4,994.6
Total Utility Operations | Operating segments | Natural gas | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 3,967.3 3,321.7 3,580.9
Total Utility Operations | Operating segments | Other non-utility revenues | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 21.8 20.4 19.6
Wisconsin | Electric | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 5,529.6 4,908.4 4,994.6
Wisconsin | Natural gas | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 1,741.6 1,402.4 1,606.7
Wisconsin | Operating segments      
Disaggregation of Operating Revenues      
Operating revenues 7,295.5 6,330.5 6,625.9
Wisconsin | Operating segments | Other operating revenues      
Disaggregation of Operating Revenues      
Other operating revenues 24.3 19.7 24.6
Wisconsin | Operating segments | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 7,271.2 6,310.8 6,601.3
Wisconsin | Operating segments | Total regulated revenues | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 7,271.2 6,310.8 6,601.3
Wisconsin | Operating segments | Electric | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 5,529.6 4,908.4 4,994.6
Wisconsin | Operating segments | Natural gas | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 1,741.6 1,402.4 1,606.7
Wisconsin | Operating segments | Other non-utility revenues | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.0
Illinois | Natural gas | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 1,717.6 1,499.6 1,480.5
Illinois | Operating segments      
Disaggregation of Operating Revenues      
Operating revenues 1,683.6 1,602.4 1,557.8
Illinois | Operating segments | Other operating revenues      
Disaggregation of Operating Revenues      
Other operating revenues (34.0) 102.8 77.3
Illinois | Operating segments | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 1,717.6 1,499.6 1,480.5
Illinois | Operating segments | Total regulated revenues | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 1,717.6 1,499.6 1,480.5
Illinois | Operating segments | Electric | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.0
Illinois | Operating segments | Natural gas | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 1,717.6 1,499.6 1,480.5
Illinois | Operating segments | Other non-utility revenues | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.0
Other States | Natural gas | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 508.1 419.7 493.7
Other States | Operating segments      
Disaggregation of Operating Revenues      
Operating revenues 527.5 449.8 519.1
Other States | Operating segments | Other operating revenues      
Disaggregation of Operating Revenues      
Other operating revenues (2.4) 9.7 5.8
Other States | Operating segments | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 529.9 440.1 513.3
Other States | Operating segments | Total regulated revenues | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 508.1 419.7 493.7
Other States | Operating segments | Electric | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.0
Other States | Operating segments | Natural gas | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 508.1 419.7 493.7
Other States | Operating segments | Other non-utility revenues | Transferred over time | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 21.8 20.4 19.6
Non-Utility Energy Infrastructure | Operating segments      
Disaggregation of Operating Revenues      
Operating revenues 770.2 691.3 666.5
Non-Utility Energy Infrastructure | Operating segments | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 290.6 272.3 259.4
Non-Utility Energy Infrastructure | Operating segments | Other operating revenues      
Disaggregation of Operating Revenues      
Other operating revenues 479.6 419.0 407.1
Non-Utility Energy Infrastructure | Operating segments | Total regulated revenues | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 47.0 48.4 61.9
Non-Utility Energy Infrastructure | Operating segments | Electric | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.0
Non-Utility Energy Infrastructure | Operating segments | Natural gas | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 47.0 48.4 61.9
Non-Utility Energy Infrastructure | Operating segments | Other non-utility revenues | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 243.6 223.9 197.5
Corporate and Other | Operating segments      
Disaggregation of Operating Revenues      
Operating revenues 0.0 0.0 0.1
Corporate and Other | Operating segments | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.1
Corporate and Other | Operating segments | Other operating revenues      
Disaggregation of Operating Revenues      
Other operating revenues 0.0 0.0 0.0
Corporate and Other | Operating segments | Total regulated revenues | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.0
Corporate and Other | Operating segments | Electric | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.0
Corporate and Other | Operating segments | Natural gas | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.0
Corporate and Other | Operating segments | Other non-utility revenues | Revenues from contracts with customers      
Disaggregation of Operating Revenues      
Revenues from contracts with customers $ 0.0 $ 0.0 $ 0.1
v3.25.4
Operating Revenues - Disaggregation of Electric Utility Operating Revenues by Customer Class (Details) - Revenues from contracts with customers - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Operating Revenues      
Revenues from contracts with customers $ 9,755.6 $ 8,467.7 $ 8,785.3
Electric      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 5,529.6 4,908.4 4,994.6
Wisconsin | Electric | Transferred over time      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 5,529.6 4,908.4 4,994.6
Wisconsin | Electric | Transferred over time | Total retail revenues      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 5,101.9 4,582.1 4,642.3
Wisconsin | Electric | Transferred over time | Residential      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 2,249.6 1,996.3 1,992.3
Wisconsin | Electric | Transferred over time | Small commercial and industrial      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 1,763.6 1,613.0 1,641.1
Wisconsin | Electric | Transferred over time | Large commercial and industrial      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 1,057.8 942.6 978.4
Wisconsin | Electric | Transferred over time | Other      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 30.9 30.2 30.5
Wisconsin | Electric | Transferred over time | Wholesale      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 107.6 102.6 120.4
Wisconsin | Electric | Transferred over time | Resale      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 267.6 176.7 195.4
Wisconsin | Electric | Transferred over time | Steam      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 28.4 22.4 25.2
Wisconsin | Electric | Transferred over time | Other utility revenues      
Disaggregation of Operating Revenues      
Revenues from contracts with customers $ 24.1 $ 24.6 $ 11.3
v3.25.4
Operating Revenues - Disaggregation of Natural Gas Utility Operating Revenues by Customer Class (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Operating Revenues        
Reduction to revenues   $ (9,800.1) $ (8,599.9) $ (8,893.0)
QIP and UEA Proposed Settlement | Illinois Commerce Commission (ICC)        
Disaggregation of Operating Revenues        
Reduction to revenues $ 75.0      
Revenues from contracts with customers        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   9,755.6 8,467.7 8,785.3
Revenues from contracts with customers | Natural gas        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   3,969.8 3,324.1 3,582.6
Revenues from contracts with customers | Natural gas | Transferred over time        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   3,967.3 3,321.7 3,580.9
Revenues from contracts with customers | Natural gas | Transferred over time | Total retail revenues        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   3,639.9 2,904.3 3,251.5
Revenues from contracts with customers | Natural gas | Transferred over time | Residential        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   2,591.6 2,089.1 2,302.4
Revenues from contracts with customers | Natural gas | Transferred over time | Commercial and industrial        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   1,048.3 815.2 949.1
Revenues from contracts with customers | Natural gas | Transferred over time | Transport        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   435.7 402.6 357.4
Revenues from contracts with customers | Natural gas | Transferred over time | Other utility revenues        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   (108.3) 14.8 (28.0)
Wisconsin | Revenues from contracts with customers | Natural gas | Transferred over time        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   1,741.6 1,402.4 1,606.7
Wisconsin | Revenues from contracts with customers | Natural gas | Transferred over time | Total retail revenues        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   1,664.1 1,309.9 1,518.7
Wisconsin | Revenues from contracts with customers | Natural gas | Transferred over time | Residential        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   1,100.2 893.1 1,012.0
Wisconsin | Revenues from contracts with customers | Natural gas | Transferred over time | Commercial and industrial        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   563.9 416.8 506.7
Wisconsin | Revenues from contracts with customers | Natural gas | Transferred over time | Transport        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   105.1 96.8 93.0
Wisconsin | Revenues from contracts with customers | Natural gas | Transferred over time | Other utility revenues        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   (27.6) (4.3) (5.0)
Illinois | Revenues from contracts with customers | Natural gas | Transferred over time        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   1,717.6 1,499.6 1,480.5
Illinois | Revenues from contracts with customers | Natural gas | Transferred over time | Total retail revenues        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   1,494.9 1,220.0 1,233.1
Illinois | Revenues from contracts with customers | Natural gas | Transferred over time | Residential        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   1,174.9 945.5 966.0
Illinois | Revenues from contracts with customers | Natural gas | Transferred over time | Commercial and industrial        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   320.0 274.5 267.1
Illinois | Revenues from contracts with customers | Natural gas | Transferred over time | Transport        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   291.8 272.2 231.9
Illinois | Revenues from contracts with customers | Natural gas | Transferred over time | Other utility revenues        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   (69.1) 7.4 15.5
Other States | Revenues from contracts with customers | Natural gas | Transferred over time        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   508.1 419.7 493.7
Other States | Revenues from contracts with customers | Natural gas | Transferred over time | Total retail revenues        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   480.9 374.4 499.7
Other States | Revenues from contracts with customers | Natural gas | Transferred over time | Residential        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   316.5 250.5 324.4
Other States | Revenues from contracts with customers | Natural gas | Transferred over time | Commercial and industrial        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   164.4 123.9 175.3
Other States | Revenues from contracts with customers | Natural gas | Transferred over time | Transport        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   38.8 33.6 32.5
Other States | Revenues from contracts with customers | Natural gas | Transferred over time | Other utility revenues        
Disaggregation of Operating Revenues        
Revenues from contracts with customers   $ (11.6) $ 11.7 $ (38.5)
v3.25.4
Operating Revenues - Other Non-Utility Operating Revenues (Details) - Revenues from contracts with customers - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Operating Revenues      
Revenues from contracts with customers $ 9,755.6 $ 8,467.7 $ 8,785.3
Other non-utility revenues      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 256.2 235.2 208.1
Other non-utility revenues | We Power revenues      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 24.6 24.3 23.5
Other non-utility revenues | Other      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 0.0 0.0 0.1
Transferred over time | Other non-utility revenues | Renewable generation revenues      
Disaggregation of Operating Revenues      
Revenues from contracts with customers 209.8 190.5 164.9
Transferred over time | Other non-utility revenues | Appliance service repairs      
Disaggregation of Operating Revenues      
Revenues from contracts with customers $ 21.8 $ 20.4 $ 19.6
v3.25.4
Operating Revenues - Other Operating Revenues (Details) - Other operating revenues - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Operating Revenues      
Other operating revenues $ 44.5 $ 132.2 $ 107.7
Late payment charges      
Disaggregation of Operating Revenues      
Other operating revenues 48.1 48.5 56.5
Bepoke resources current return      
Disaggregation of Operating Revenues      
Other operating revenues 4.1 0.0  
Alternative revenues      
Disaggregation of Operating Revenues      
Other operating revenues (67.7) 79.8 47.0
Other      
Disaggregation of Operating Revenues      
Other operating revenues $ 60.0 $ 3.9 $ 4.2
v3.25.4
Credit Losses - Gross Receivables and Related Allowances (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Accounts receivable and unbilled revenues $ 2,211.4 $ 1,832.1    
Allowance for credit losses 148.7 162.8 $ 193.5 $ 199.3
Accounts receivable and unbilled revenues, net 2,062.7 1,669.3    
Total accounts receivable, net - past due greater than 90 days $ 89.8 $ 84.4    
Past due greater than 90 days - collection risk mitigated by regulatory mechanisms 89.90% 93.20%    
Amount of net accounts receivable with regulatory protections $ 1,290.2      
Percent of net accounts receivable with regulatory protections 62.50%      
Public utilities        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Accounts receivable and unbilled revenues $ 2,153.8 $ 1,786.1    
Allowance for credit losses 148.7 162.8    
Accounts receivable and unbilled revenues, net 2,005.1 1,623.3    
Total accounts receivable, net - past due greater than 90 days $ 89.8 $ 84.4    
Past due greater than 90 days - collection risk mitigated by regulatory mechanisms 89.90% 93.20%    
Wisconsin | Public utilities        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Accounts receivable and unbilled revenues $ 1,368.8 $ 1,149.9    
Allowance for credit losses 61.7 73.6 77.4 82.0
Accounts receivable and unbilled revenues, net 1,307.1 1,076.3    
Total accounts receivable, net - past due greater than 90 days $ 46.4 $ 51.8    
Past due greater than 90 days - collection risk mitigated by regulatory mechanisms 94.60% 93.80%    
Illinois | Public utilities        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Accounts receivable and unbilled revenues $ 654.8 $ 535.6    
Allowance for credit losses 82.3 83.9 109.7 111.0
Accounts receivable and unbilled revenues, net 572.5 451.7    
Total accounts receivable, net - past due greater than 90 days $ 36.8 $ 30.1    
Past due greater than 90 days - collection risk mitigated by regulatory mechanisms 100.00% 100.00%    
Other States | Public utilities        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Accounts receivable and unbilled revenues $ 130.2 $ 100.6    
Allowance for credit losses 4.7 5.3 $ 6.4 $ 6.3
Accounts receivable and unbilled revenues, net 125.5 95.3    
Total accounts receivable, net - past due greater than 90 days $ 6.6 $ 2.5    
Past due greater than 90 days - collection risk mitigated by regulatory mechanisms 0.00% 0.00%    
Non-Utility Energy Infrastructure        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Accounts receivable and unbilled revenues $ 50.3 $ 40.0    
Allowance for credit losses 0.0 0.0    
Accounts receivable and unbilled revenues, net 50.3 40.0    
Total accounts receivable, net - past due greater than 90 days $ 0.0 $ 0.0    
Past due greater than 90 days - collection risk mitigated by regulatory mechanisms 0.00% 0.00%    
Corporate and Other        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Accounts receivable and unbilled revenues $ 7.3 $ 6.0    
Allowance for credit losses 0.0 0.0    
Accounts receivable and unbilled revenues, net 7.3 6.0    
Total accounts receivable, net - past due greater than 90 days $ 0.0 $ 0.0    
Past due greater than 90 days - collection risk mitigated by regulatory mechanisms 0.00% 0.00%    
v3.25.4
Credit Losses - Rollforward of Allowances (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Accounts Receivable, Allowance for Credit Loss [Roll Forward]      
Balance at Beginning of Year $ 162.8 $ 193.5 $ 199.3
Provision for credit losses 142.8 104.9 72.0
Write-offs charged against the allowance (241.0) (243.4) (223.6)
Recovery of amounts previously written off 107.9 72.0 57.5
Balance at End of Year 148.7 162.8 193.5
Change in allowance for credit losses 14.1 30.7 5.8
Uncollectible expense      
Accounts Receivable, Allowance for Credit Loss [Roll Forward]      
Provision for credit losses deferred for future recovery or refund (23.8) 35.8 88.3
Public utilities      
Accounts Receivable, Allowance for Credit Loss [Roll Forward]      
Balance at Beginning of Year 162.8    
Balance at End of Year 148.7 162.8  
Wisconsin | Public utilities      
Accounts Receivable, Allowance for Credit Loss [Roll Forward]      
Balance at Beginning of Year 73.6 77.4 82.0
Provision for credit losses 85.0 52.1 40.9
Write-offs charged against the allowance (151.4) (141.8) (131.6)
Recovery of amounts previously written off 49.6 42.1 33.6
Balance at End of Year 61.7 73.6 77.4
Wisconsin | Public utilities | Uncollectible expense      
Accounts Receivable, Allowance for Credit Loss [Roll Forward]      
Provision for credit losses deferred for future recovery or refund 4.9 43.8 52.5
Illinois | Public utilities      
Accounts Receivable, Allowance for Credit Loss [Roll Forward]      
Balance at Beginning of Year 83.9 109.7 111.0
Provision for credit losses 55.8 52.3 26.3
Write-offs charged against the allowance (81.2) (95.0) (85.4)
Recovery of amounts previously written off 52.5 24.9 22.0
Balance at End of Year 82.3 83.9 109.7
Illinois | Public utilities | Uncollectible expense      
Accounts Receivable, Allowance for Credit Loss [Roll Forward]      
Provision for credit losses deferred for future recovery or refund (28.7) (8.0) 35.8
Other States | Public utilities      
Accounts Receivable, Allowance for Credit Loss [Roll Forward]      
Balance at Beginning of Year 5.3 6.4 6.3
Provision for credit losses 2.0 0.5 4.8
Write-offs charged against the allowance (8.4) (6.6) (6.6)
Recovery of amounts previously written off 5.8 5.0 1.9
Balance at End of Year 4.7 5.3 6.4
Other States | Public utilities | Uncollectible expense      
Accounts Receivable, Allowance for Credit Loss [Roll Forward]      
Provision for credit losses deferred for future recovery or refund $ 0.0 $ 0.0 $ 0.0
v3.25.4
Regulatory Assets and Liabilities - Regulatory Assets (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Jan. 01, 2020
Regulatory assets      
Other current assets $ 17.3 $ 39.0  
Regulatory assets 3,156.3 3,339.7  
Total regulatory assets 3,173.6 3,378.7  
Allowance for return on equity capitalized for regulatory purposes 20.9 26.7  
Regulatory assets not earning a return 183.1    
Regulatory assets earning a return based on short-term interest rates 1.3    
Regulatory assets earning a return based on long-term interest rates 106.1    
Regulatory assets earning a return based on return on equity rates 5.5    
Estimated future cash expenditures for environmental remediation 484.1 445.8  
Plant retirement related items      
Regulatory assets      
Total regulatory assets 768.6 810.5  
Regulatory assets not earning a return 100.0    
Environmental remediation costs      
Regulatory assets      
Total regulatory assets 566.0 570.1  
Cash expenditures for environmental remediation costs 81.9    
Estimated future cash expenditures for environmental remediation 484.1    
Pension and OPEB costs      
Regulatory assets      
Total regulatory assets 564.5 684.9  
Income tax related items      
Regulatory assets      
Total regulatory assets 493.4 438.5  
Asset retirement obligations (AROs)      
Regulatory assets      
Total regulatory assets 185.1 166.7  
Uncollectible expense      
Regulatory assets      
Total regulatory assets 123.9 151.5  
System support resource (SSR)      
Regulatory assets      
Total regulatory assets 92.6 102.9  
Recovery period of regulatory asset     15 years
Securitization      
Regulatory assets      
Total regulatory assets 67.5 76.5  
Derivatives      
Regulatory assets      
Total regulatory assets 57.7 38.2  
Decoupling      
Regulatory assets      
Total regulatory assets 43.8 110.0  
Bluewater      
Regulatory assets      
Total regulatory assets 37.7 57.7  
Finance and operating leases      
Regulatory assets      
Total regulatory assets 36.0 22.0  
Electric transmission costs      
Regulatory assets      
Total regulatory assets 30.7 0.4  
Energy efficiency programs      
Regulatory assets      
Total regulatory assets 11.6 26.5  
Other, net      
Regulatory assets      
Total regulatory assets $ 94.5 $ 122.3  
v3.25.4
Regulatory Assets and Liabilities - Regulatory Liabilities (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Regulatory liabilities    
Other current liabilities $ 88.9 $ 45.3
Regulatory liabilities 4,121.3 3,958.0
Total regulatory liabilities 4,210.2 4,003.3
Income tax related items    
Regulatory liabilities    
Total regulatory liabilities 1,802.4 1,825.4
Removal costs    
Regulatory liabilities    
Total regulatory liabilities 1,584.7 1,458.2
Pension and OPEB benefits    
Regulatory liabilities    
Total regulatory liabilities 301.5 308.5
Proposed settlement related to QIP and UEA riders    
Regulatory liabilities    
Total regulatory liabilities 125.0 0.0
Energy costs refundable through rate adjustments    
Regulatory liabilities    
Total regulatory liabilities 119.2 160.8
Uncollectible expense    
Regulatory liabilities    
Total regulatory liabilities 73.1 47.2
Earnings sharing mechanisms    
Regulatory liabilities    
Total regulatory liabilities 35.8 7.1
Derivatives    
Regulatory liabilities    
Total regulatory liabilities 27.4 36.9
MERC property tax tracker    
Regulatory liabilities    
Total regulatory liabilities 23.1 19.3
Revenue requirements of renewable generation facilities    
Regulatory liabilities    
Total regulatory liabilities 14.5 44.2
Other, net    
Regulatory liabilities    
Total regulatory liabilities $ 103.5 $ 95.7
v3.25.4
Regulatory Assets and Liabilities - Oak Creek Power Plant Units 5-6 (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Regulatory assets    
Regulatory asset $ 3,173.6 $ 3,378.7
Regulatory liability 4,210.2 4,003.3
Deferred tax liabilities 5,041.5 $ 4,545.2
Oak Creek power plant units 5 and 6    
Regulatory assets    
Regulatory asset 68.3  
Regulatory liability 45.0  
Deferred tax liabilities $ 6.3  
v3.25.4
Property, Plant, and Equipment - Balances (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Property, plant, and equipment    
Accumulated depreciation $ 12,411.5 $ 11,611.9
Net property, plant, and equipment 38,278.1 34,645.4
OCPP Units 7 and 8 | WE    
Property, plant, and equipment    
Net book value of plant to be retired 621.7  
Columbia Units 1 and 2 | WPS    
Property, plant, and equipment    
Net book value of plant to be retired 236.8  
Property under finance leases    
Property, plant, and equipment    
Property under finance leases 351.8 291.3
Less: Accumulated amortization 16.3 10.0
Net leased facilities 335.5 281.3
Regulated operations    
Property, plant, and equipment    
Accumulated depreciation 10,180.2 9,401.0
Net 27,094.9 25,573.0
CWIP 3,364.4 1,653.6
Net property, plant, and equipment 30,459.3 27,226.6
Regulated operations | Electric - generation    
Property, plant, and equipment    
Property, plant, and equipment 7,998.3 6,685.0
Regulated operations | Electric - distribution    
Property, plant, and equipment    
Property, plant, and equipment 10,048.9 9,298.9
Regulated operations | Natural gas - distribution, storage, and transmission    
Property, plant, and equipment    
Property, plant, and equipment 16,175.0 15,673.0
Regulated operations | Property, plant, and equipment to be retired, net    
Property, plant, and equipment    
Property, plant, and equipment to be retired, net 621.7 906.3
Regulated operations | Other    
Property, plant, and equipment    
Property, plant, and equipment 2,431.2 2,410.8
Non-regulated operations    
Property, plant, and equipment    
Accumulated depreciation 1,559.1 1,393.9
Net 7,422.5 7,096.2
CWIP 60.8 41.3
Net property, plant, and equipment 7,483.3 7,137.5
Non-regulated operations | Other    
Property, plant, and equipment    
Property, plant, and equipment 11.3 14.1
Non-regulated operations | We Power generation    
Property, plant, and equipment    
Property, plant, and equipment 3,250.7 3,284.3
Non-regulated operations | Renewable generation    
Property, plant, and equipment    
Property, plant, and equipment 5,252.4 4,720.8
Non-regulated operations | Natural gas storage    
Property, plant, and equipment    
Property, plant, and equipment 299.6 298.6
Non-regulated operations | Corporate services    
Property, plant, and equipment    
Property, plant, and equipment 167.6 172.3
Non-Utility Energy Infrastructure | Non-regulated operations    
Property, plant, and equipment    
Property, plant, and equipment $ 8,802.7 $ 8,303.7
v3.25.4
Property, Plant, and Equipment - Severance Liability (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Property, Plant and Equipment [Abstract]      
Severance liability at January 1 $ 13.4 $ 17.8 $ 16.2
Severance expense 0.0   1.6
Severance accrual adjustment   (3.9)  
Severance payments (0.7) (0.5) 0.0
Severance liability at December 31 $ 12.7 $ 13.4 $ 17.8
v3.25.4
Property, Plant, and Equipment - Oak Creek Power Plant Units 7 and 8 (Details)
$ in Millions
Dec. 31, 2025
USD ($)
WE | OCPP Units 7 and 8  
Property, plant, and equipment  
Net book value of plant to be retired $ 621.7
v3.25.4
Property, Plant, and Equipment - Columbia Energy Center Units 1 and 2 (Details)
$ in Millions
Dec. 31, 2025
USD ($)
WPS | Columbia Units 1 and 2  
Property, plant, and equipment  
Net book value of plant to be retired $ 236.8
v3.25.4
Property, Plant, and Equipment - Samson and Delilah Storm Damage (Details) - Electric - generation - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Sep. 30, 2025
Jun. 30, 2025
Dec. 31, 2025
Samson I Solar Energy Center      
Property, plant, and equipment      
Impairment of Samson I   $ 2.8 $ 2.8
Insurance receivable     $ 2.8
Samson I Solar Energy Center LLC and Delilah Solar Energy LLC      
Property, plant, and equipment      
Impairment of Samson I $ 12.0 $ 8.8  
v3.25.4
Property, Plant, and Equipment - PGL and NSG Impairment (Details) - USD ($)
$ in Millions
1 Months Ended 3 Months Ended 12 Months Ended
Nov. 30, 2023
Dec. 31, 2025
Sep. 30, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Property, plant, and equipment            
Impairments related to Illinois segment       $ 130.0 $ 12.1 $ 178.9
PGL            
Property, plant, and equipment            
Impairments related to Illinois segment $ 177.2 $ 130.0 $ 12.1      
NSG            
Property, plant, and equipment            
Impairments related to Illinois segment 1.7          
PGL and NSG            
Property, plant, and equipment            
Impairments related to Illinois segment $ 178.9          
v3.25.4
Jointly Owned Utility Facilities In-service (Details)
$ in Millions
Dec. 31, 2025
USD ($)
MW
May 31, 2024
MW
Jun. 30, 2023
WE | West Riverside      
Jointly owned utility facilities      
Joint plant ownership percentage   27.50%  
Share of capacity (MW) | MW   200  
ER 1 & ER2 | We Power      
Jointly owned utility facilities      
Joint plant ownership percentage 83.34%    
Share of capacity (MW) | MW 1,083.4    
Property, plant, and equipment $ 2,489.4    
Accumulated depreciation (542.0)    
CWIP $ 4.6    
Weston Unit 4 | WPS      
Jointly owned utility facilities      
Joint plant ownership percentage 70.00%    
Share of capacity (MW) | MW 379.8    
Property, plant, and equipment $ 600.6    
Accumulated depreciation (242.7)    
CWIP $ 4.5    
Columbia Units 1 and 2 | WPS      
Jointly owned utility facilities      
Joint plant ownership percentage 27.50%    
Share of capacity (MW) | MW 306.2    
Property, plant, and equipment $ 439.1    
Accumulated depreciation (201.6)    
CWIP $ 5.0    
Forward Wind | WPS      
Jointly owned utility facilities      
Joint plant ownership percentage 44.60%    
Share of capacity (MW) | MW 61.5    
Property, plant, and equipment $ 120.3    
Accumulated depreciation (63.3)    
CWIP $ 13.9    
Two Creeks | WPS      
Jointly owned utility facilities      
Joint plant ownership percentage 66.70%    
Share of capacity (MW) | MW 100.0    
Property, plant, and equipment $ 135.7    
Accumulated depreciation (22.9)    
CWIP $ 0.0    
Badger Hollow I | WPS      
Jointly owned utility facilities      
Joint plant ownership percentage 66.70%    
Share of capacity (MW) | MW 100.0    
Property, plant, and equipment $ 146.0    
Accumulated depreciation (19.0)    
CWIP $ 0.0    
Red Barn | WPS      
Jointly owned utility facilities      
Joint plant ownership percentage 90.00%    
Share of capacity (MW) | MW 82.4    
Property, plant, and equipment $ 150.7    
Accumulated depreciation (12.8)    
CWIP $ 0.0    
West Riverside | WE      
Jointly owned utility facilities      
Joint plant ownership percentage 27.50% 13.70% 13.80%
Share of capacity (MW) | MW 190.2    
Property, plant, and equipment $ 223.6    
Accumulated depreciation (36.7)    
CWIP $ 2.2    
Badger Hollow II | WE      
Jointly owned utility facilities      
Joint plant ownership percentage 66.70%    
Share of capacity (MW) | MW 100.0    
Property, plant, and equipment $ 179.3    
Accumulated depreciation (11.8)    
CWIP $ 0.0    
Paris Solar | WE and WPS      
Jointly owned utility facilities      
Joint plant ownership percentage 90.00%    
Share of capacity (MW) | MW 180.0    
Property, plant, and equipment $ 359.3    
Accumulated depreciation (11.0)    
CWIP $ 0.0    
Paris Battery | WE and WPS      
Jointly owned utility facilities      
Joint plant ownership percentage 90.00%    
Share of capacity (MW) | MW 99.0    
Property, plant, and equipment $ 236.8    
Accumulated depreciation (5.5)    
CWIP $ 0.0    
Darien Solar | WE and WPS      
Jointly owned utility facilities      
Joint plant ownership percentage 90.00%    
Share of capacity (MW) | MW 225.0    
Property, plant, and equipment $ 460.1    
Accumulated depreciation (10.7)    
CWIP $ 0.0    
v3.25.4
Jointly Owned Utility Facilities Approved by PSCW (Details) - WE and WPS
$ in Millions
Dec. 31, 2025
USD ($)
MW
Koshkonong Solar  
Jointly owned utility facilities  
Joint plant ownership percentage 90.00%
Share of capacity (MW) | MW 270.0
CWIP | $ $ 460.6
Koshkonong Battery  
Jointly owned utility facilities  
Joint plant ownership percentage 90.00%
Share of capacity (MW) | MW 149.0
CWIP | $ $ 150.7
Darien Battery  
Jointly owned utility facilities  
Joint plant ownership percentage 90.00%
Share of capacity (MW) | MW 68.0
CWIP | $ $ 68.3
High Noon Solar  
Jointly owned utility facilities  
Joint plant ownership percentage 90.00%
Share of capacity (MW) | MW 270.0
CWIP | $ $ 404.2
High Noon Battery  
Jointly owned utility facilities  
Joint plant ownership percentage 90.00%
Share of capacity (MW) | MW 149.0
CWIP | $ $ 150.8
Ursa Solar Electric Generation Facility  
Jointly owned utility facilities  
Joint plant ownership percentage 90.00%
Share of capacity (MW) | MW 180.0
CWIP | $ $ 57.1
Saratoga Solar  
Jointly owned utility facilities  
Joint plant ownership percentage 90.00%
Share of capacity (MW) | MW 135.0
CWIP | $ $ 39.2
Saratoga Battery  
Jointly owned utility facilities  
Joint plant ownership percentage 90.00%
Share of capacity (MW) | MW 45.0
CWIP | $ $ 53.2
Badger Hollow Wind Energy Generation Facility  
Jointly owned utility facilities  
Joint plant ownership percentage 90.00%
Share of capacity (MW) | MW 100.0
CWIP | $ $ 50.0
Whitetail  
Jointly owned utility facilities  
Joint plant ownership percentage 90.00%
Share of capacity (MW) | MW 60.0
CWIP | $ $ 9.0
v3.25.4
Asset Retirement Obligations (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Changes to asset retirement obligations      
Balance as of January 1 $ 580.0 $ 374.2 $ 479.3
Accretion 26.6 18.8 17.2
Additions 29.6 192.7 24.0
Revisions to estimated cash flows 23.7 6.4 (133.5)
Liabilities settled (12.9) (12.1) (12.8)
Balance as of December 31 $ 647.0 $ 580.0 $ 374.2
v3.25.4
Goodwill and Intangibles - Goodwill (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Sep. 30, 2025
Dec. 31, 2025
Dec. 31, 2024
Goodwill      
Changes to the carrying amount of goodwill   $ 0.0 $ 0.0
Goodwill   3,052.8 3,052.8
Accumulated impairment losses   0.0  
Goodwill impairment loss $ 0.0    
Wisconsin      
Goodwill      
Goodwill   2,104.3 2,104.3
Illinois      
Goodwill      
Goodwill   758.7 758.7
Other States      
Goodwill      
Goodwill   183.2 183.2
Non-Utility Energy Infrastructure      
Goodwill      
Goodwill   $ 6.6 $ 6.6
v3.25.4
Goodwill and Intangibles - Indefinite Lived Intangible Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Indefinite-lived Intangible Assets    
Indefinite-lived intangible assets $ 44.4 $ 29.3
Option to purchase land 15.1  
Spectrum frequencies    
Indefinite-lived Intangible Assets    
Indefinite-lived intangible assets 24.1 24.1
MGU | Trade name    
Indefinite-lived Intangible Assets    
Indefinite-lived intangible assets $ 5.2 $ 5.2
v3.25.4
Goodwill and Intangibles - Finite-lived Intangible Asset (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Amortization to be recorded as a decrease to operating revenues    
Amortization to be recorded in the next five years    
2026 $ 59.9  
2027 59.9  
2028 59.9  
2029 59.9  
2030 59.9  
Maple Flats | Amortization to be recorded as a decrease to operating revenues    
Amortization to be recorded in the next five years    
2026 1.3  
2027 1.3  
2028 1.3  
2029 1.3  
2030 1.3  
PPAs | Maple Flats    
Finite-Lived Intangible Asset    
Gross carrying amount $ 18.8 $ 13.0
Weighted average useful life 15 years  
v3.25.4
Goodwill and Intangibles - Intangible Liabilities (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Finite-Lived Intangible Liabilities      
Amortization $ 58.1 $ 53.7 $ 50.6
Period of amortization 5 years    
Amortization to be recorded as an increase to operating revenues      
Amortization to be recorded in the next five years      
2026 $ 59.9    
2027 59.9    
2028 59.9    
2029 59.9    
2030 59.9    
Amortization to be recorded as a decrease to other operation and maintenance      
Amortization to be recorded in the next five years      
2026 0.2    
2027 0.2    
2028 0.2    
2029 0.2    
2030 0.2    
WECI      
Finite-Lived Intangible Liabilities      
Gross carrying amount 763.1 691.5  
Accumulated Amortization (182.8) (124.7)  
Net Carrying Amount 580.3 566.8  
PPAs | WECI      
Finite-Lived Intangible Liabilities      
Gross carrying amount 751.2 679.6  
Accumulated Amortization (176.5) (119.3)  
Net Carrying Amount $ 574.7 560.3  
PPAs | Blooming Grove, Tatanka Ridge, Jayhawk, Thunderhead, Samson I, Sapphire Sky, Delilah I, and Hardin III      
Finite-Lived Intangible Liabilities      
Weighted average useful life 10 years    
Proxy revenue swap | WECI      
Finite-Lived Intangible Liabilities      
Gross carrying amount $ 7.2 7.2  
Accumulated Amortization (4.9) (4.2)  
Net Carrying Amount $ 2.3 3.0  
Proxy revenue swap | Upstream Wind Energy LLC      
Finite-Lived Intangible Liabilities      
Weighted average useful life 3 years    
Length of proxy revenue contract, in years 10 years    
Interconnection agreements | WECI      
Finite-Lived Intangible Liabilities      
Gross carrying amount $ 4.7 4.7  
Accumulated Amortization (1.4) (1.2)  
Net Carrying Amount $ 3.3 $ 3.5  
Interconnection agreements | Tatanka Ridge and Bishop Hill III      
Finite-Lived Intangible Liabilities      
Weighted average useful life 15 years    
v3.25.4
Common Equity - Stock-Based Compensation Expense (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award      
Stock-based compensation expense $ 48.2 $ 39.3 $ 9.7
Related tax benefit 13.2 10.8 2.7
Stock options      
Share Based Compensation Arrangement By Share Based Payment Award      
Stock-based compensation expense 4.1 4.9 5.3
Restricted stock      
Share Based Compensation Arrangement By Share Based Payment Award      
Stock-based compensation expense 6.2 7.6 6.6
Performance units      
Share Based Compensation Arrangement By Share Based Payment Award      
Stock-based compensation expense $ 37.9 $ 26.8 $ (2.2)
v3.25.4
Common Equity - Stock Options (Details) - Stock options - USD ($)
$ / shares in Units, $ in Millions
2 Months Ended 12 Months Ended
Feb. 20, 2026
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Options Activity        
Outstanding, shares, beginning balance 2,569,487 2,916,902    
Granted, shares   231,024 294,990 257,780
Exercised, shares   (575,758)    
Forfeited, shares   (1,351)    
Expired, shares   (1,330)    
Outstanding, shares, ending balance   2,569,487 2,916,902  
Options - Weighted Average Exercise Price        
Outstanding, Weighted-Average Exercise Price, Beginning $ 86.65 $ 82.32    
Granted, Weighted-Average Exercise Price   94.55    
Exercised, Weighted-Average Exercise Price   67.92    
Forfeited, Weighted-Average Exercise Price   91.11    
Expired, Weighted Average Exercise Price   52.90    
Outstanding, Weighted-Average Exercise Price, Ending   $ 86.65 $ 82.32  
Options - Additional Disclosures        
Outstanding, Weighted-Average Remaining Contractual Life (Years)   5 years 3 months 18 days    
Outstanding, Aggregate Intrinsic Value   $ 48.3    
Exercisable, shares   1,937,953    
Exercisable, Weighted-Average Exercise Price (in dollars per share)   $ 85.29    
Exercisable, Weighted-Average Remaining Contractual Life (Years)   4 years 4 months 24 days    
Exercisable, Aggregate Intrinsic Value   $ 39.1    
Intrinsic value of options exercised   22.8 $ 11.2 $ 5.2
Tax benefit from option exercises   6.3 $ 3.1 $ 1.4
Compensation cost not yet recognized   $ 1.4    
Weighted-average period over which unrecognized compensation cost is expected to be recognized   1 year 8 months 12 days    
Estimated weighted-average fair value per stock option (in dollars per share)   $ 18.23 $ 16.19 $ 19.58
Subsequent event        
Options Activity        
Granted, shares 269,085      
Options - Weighted Average Exercise Price        
Granted, Weighted-Average Exercise Price $ 106.09      
Options - Additional Disclosures        
Estimated weighted-average fair value per stock option (in dollars per share) $ 21.20      
v3.25.4
Common Equity - Restricted Shares (Details) - Restricted stock - USD ($)
$ / shares in Units, $ in Millions
2 Months Ended 12 Months Ended
Feb. 20, 2026
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Restricted Stock Activity        
Outstanding, shares, beginning of period 118,913 105,242    
Granted, shares   79,170    
Released, shares   (58,725)    
Forfeited, shares   (6,774)    
Outstanding, shares, end of period   118,913 105,242  
Restricted Stock Weighted-Average Grant Date Fair Value        
Outstanding, weighted-average grant date fair value, beginning of period $ 91.61 $ 87.61    
Granted, weighted-average grant date fair value   94.55    
Released, weighted-average grant date fair value   88.48    
Forfeited, weighted-average grant date fair value   90.88    
Outstanding, weighted-average grant date fair value, end of period   $ 91.61 $ 87.61  
Restricted Stock - Additional Disclosures        
Intrinsic value of released restricted shares   $ 5.7 $ 8.6 $ 5.8
Tax benefit from released restricted shares   1.6 $ 2.4 $ 1.6
Compensation cost not yet recognized   $ 4.9    
Weighted-average period over which unrecognized compensation cost is expected to be recognized   1 year 8 months 12 days    
Subsequent event        
Restricted Stock Activity        
Granted, shares 75,222      
Restricted Stock Weighted-Average Grant Date Fair Value        
Granted, weighted-average grant date fair value $ 106.09      
v3.25.4
Common Equity - Performance Units (Details) - Performance units - USD ($)
$ in Millions
2 Months Ended 12 Months Ended
Feb. 20, 2026
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award        
Performance units granted   185,945 205,051 157,035
Intrinsic value of settled performance units   $ 15.4 $ 2.4 $ 10.2
Tax benefit from distribution of performance units   $ 3.8 $ 0.6 $ 2.6
Performance units outstanding   502,733    
Liability recorded on balance sheet   $ 57.1    
Compensation cost not yet recognized   $ 31.3    
Weighted-average period over which unrecognized compensation cost is expected to be recognized   1 year 8 months 12 days    
Subsequent event        
Share-based Compensation Arrangement by Share-based Payment Award        
Performance units granted 182,146      
Intrinsic value of settled performance units $ 25.2      
Tax benefit from distribution of performance units $ 5.7      
v3.25.4
Common Equity - Dividend Restrictions (Details)
$ in Millions
12 Months Ended
Dec. 31, 2025
USD ($)
period
Dividend Payment Restrictions  
Restricted net assets of consolidated subsidiaries $ 14,000
Undistributed earnings of investees accounted for by the equity method $ 615
WEC Energy Group  
Dividend Payment Restrictions  
Maximum debt to capitalization ratio 70.00%
Junior notes minimum interest deferral payment period (in periods) | period 1
Junior notes maximum interest payment deferral period (in years) 10 years
WE  
Dividend Payment Restrictions  
Maximum debt to capitalization ratio 65.00%
WE | 3.60% Serial Preferred Stock  
Dividend Payment Restrictions  
Dividend rate (as a percent) 3.60%
WE | 3.60% Serial Preferred Stock | Common stock equity to total capitalization is between 25% and 20%  
Dividend Payment Restrictions  
Period of dividend restrictions 12 months
WE | 3.60% Serial Preferred Stock | Common stock equity to total capitalization is less than 20%  
Dividend Payment Restrictions  
Period of dividend restrictions 12 months
WE | 3.60% Serial Preferred Stock | Minimum | Common stock equity to total capitalization is between 25% and 20%  
Dividend Payment Restrictions  
Percentage of common equity to total capitalization required to be maintained 20.00%
WE | 3.60% Serial Preferred Stock | Maximum | Common stock equity to total capitalization is between 25% and 20%  
Dividend Payment Restrictions  
Percentage of net income for which dividends can be declared 75.00%
Percentage of common equity to total capitalization required to be maintained 25.00%
WE | 3.60% Serial Preferred Stock | Maximum | Common stock equity to total capitalization is less than 20%  
Dividend Payment Restrictions  
Percentage of net income for which dividends can be declared 50.00%
Percentage of common equity to total capitalization required to be maintained 20.00%
WE | Public Service Commission of Wisconsin | Minimum  
Dividend Payment Restrictions  
Common equity ratio required to be maintained (as a percent) 53.00%
WPS  
Dividend Payment Restrictions  
Maximum debt to capitalization ratio 65.00%
WPS | Public Service Commission of Wisconsin | Minimum  
Dividend Payment Restrictions  
Common equity ratio required to be maintained (as a percent) 53.00%
WG | Public Service Commission of Wisconsin | Minimum  
Dividend Payment Restrictions  
Common equity ratio required to be maintained (as a percent) 53.00%
UMERC  
Dividend Payment Restrictions  
Maximum debt to capitalization ratio 65.00%
Bluewater Gas Storage, LLC  
Dividend Payment Restrictions  
Maximum debt to capitalization ratio 65.00%
ATC Holding LLC  
Dividend Payment Restrictions  
Maximum debt to capitalization ratio 65.00%
WECI Wind Holding I  
Dividend Payment Restrictions  
Minimum debt service ratio to be maintained for 12-months prior to distribution 1.2
WECI Wind Holding II  
Dividend Payment Restrictions  
Minimum debt service ratio to be maintained for 12-months prior to distribution 1.2
WECI Energy Holding III  
Dividend Payment Restrictions  
Minimum debt service ratio to be maintained for 12-months prior to distribution 1.2
v3.25.4
Common Equity - Common Stock - ATM Program (Details) - USD ($)
$ / shares in Units, $ in Millions
1 Months Ended 2 Months Ended 12 Months Ended 15 Months Ended
Nov. 30, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Oct. 31, 2025
Aug. 01, 2024
Stockholders' Equity Note [Abstract]              
New shares of common stock issued         0    
Capital Unit [Line Items]              
Shares issued - At-the-market offering program     6,579,783 1,030,674      
Proceeds from issuance of common stock, net     $ 761.9 $ 163.4 $ 0.0    
Common stock issued under forward sales contract         0    
At-the-market program offering              
Capital Unit [Line Items]              
Maximum aggregate sales of common stock through ATM Program           $ 3,000.0 $ 1,500.0
Shares issued - At-the-market offering program           7,610,457  
Proceeds from issuance of common stock, net           $ 797.3  
Payments of Stock Issuance Costs           $ 9.2  
At-the-market program offering | November 2025 Forward Sales Contract              
Stockholders' Equity Note [Abstract]              
New shares of common stock issued   0          
Capital Unit [Line Items]              
Forward Contract Indexed to Issuer's Equity, Shares 58,533            
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share $ 110.7748            
Common stock issued under forward sales contract   0          
At-the-market program offering | November 2025 Forward Sales Contract | Physical Settlement              
Capital Unit [Line Items]              
Forward Contract Indexed to Equity, Settlement, Number of Shares   58,533 58,533        
Forward Contract Indexed to Equity, Settlement, Cash, Amount   $ 6.5 $ 6.5        
At-the-market program offering | November 2025 Forward Sales Contract | Net Share Settlement              
Capital Unit [Line Items]              
Forward Contract Indexed to Equity, Settlement, Number of Shares   3,084 3,084        
Forward Contract Indexed to Equity, Settlement, Cash, Amount   $ 0.3 $ 0.3        
v3.25.4
Common Equity - Common Stock Issued and Purchased (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Roll Forward of Common Stock Outstanding      
Common Stock, Shares, Outstanding, Beginning Balance 317,680,855 315,434,531  
Shares issued - At-the-market offering program 6,579,783 1,030,674  
Shares issued - Stock-based compensation 609,995 455,474  
Shares issued - 401(k) 247,889 336,800  
Shares issued - Stock investment plan 342,997 423,376  
Common Stock, Shares, Outstanding, Ending Balance 325,461,519 317,680,855 315,434,531
Common Stock, Shares, Issued 325,461,519 317,680,855  
Shares purchased      
Shares purchased 13,795 23,292 182,795
Cost of shares purchased $ 1.3 $ 3.2 $ 16.6
v3.25.4
Common Equity - Common Stock Dividends (Details) - $ / shares
1 Months Ended 3 Months Ended 12 Months Ended
Jan. 22, 2026
Dec. 31, 2025
Sep. 30, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dividends Paid and Payable                
Dividends per share (in dollars per share)           $ 3.57 $ 3.34 $ 3.12
OQ12025Dividends                
Dividends Paid and Payable                
Dividends per share (in dollars per share)         $ 0.8925      
OQ22025Dividends                
Dividends Paid and Payable                
Dividends per share (in dollars per share)       $ 0.8925        
OQ32025Dividends                
Dividends Paid and Payable                
Dividends per share (in dollars per share)     $ 0.8925          
OQ42025 Dividends                
Dividends Paid and Payable                
Dividends per share (in dollars per share)   $ 0.8925            
Subsequent event                
Dividends Paid and Payable                
Annual dividends (in dollars per share) $ 3.81              
Subsequent event | OQ12026Dividends                
Dividends Paid and Payable                
Dividends per share (in dollars per share) $ 0.9525              
v3.25.4
Common Equity - EPS (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]      
Net income attributed to common shareholders $ 1,557.5 $ 1,527.2 $ 1,331.7
Weighted average basic shares outstanding 321.9 316.2 315.4
Dilutive effect of stock-based compensation awards 0.6 0.3 0.5
Dilutive effect of convertible senior notes 1.3 0.0 0.0
Weighted average diluted shares 323.8 316.5 315.9
Basic EPS $ 4.84 $ 4.83 $ 4.22
Diluted EPS $ 4.81 $ 4.83 $ 4.22
v3.25.4
Preferred Stock (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]    
Total preferred stock value issued $ 30.4 $ 30.4
WEC Energy Group | $.01 par value Preferred Stock    
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]    
Par or stated value per share $ 0.01  
Shares authorized 15,000,000 15,000,000
Shares outstanding 0  
Redemption price per share $ 0 $ 0
Total preferred stock value issued $ 0.0  
WE | $100 par value, Six Per Cent. Preferred Stock    
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]    
Par or stated value per share $ 100  
Dividend rate (as a percent) 6.00% 6.00%
Shares authorized 45,000 45,000
Shares outstanding 44,498 44,498
Redemption price per share $ 0  
Total preferred stock value issued $ 4.4  
WE | $100 par value, Serial Preferred Stock, 3.60% series    
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]    
Par or stated value per share $ 100  
Dividend rate (as a percent) 3.60%  
Shares authorized 2,286,500 2,286,500
Shares outstanding 260,000  
Redemption price per share $ 101 $ 101
Total preferred stock value issued $ 26.0  
WE | $25 par value, Serial Preferred Stock    
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]    
Par or stated value per share $ 25  
Shares authorized 5,000,000 5,000,000
Shares outstanding 0 0
Redemption price per share $ 0 $ 0
Total preferred stock value issued $ 0.0  
WPS | $100 par value, Preferred Stock    
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]    
Par or stated value per share $ 100  
Shares authorized 1,000,000  
Shares outstanding 0  
Redemption price per share $ 0 $ 0
Total preferred stock value issued $ 0.0 $ 0.0
PGL | $100 par value, Cumulative Preferred Stock    
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]    
Par or stated value per share $ 100  
Shares authorized 430,000 430,000
Shares outstanding 0  
Redemption price per share $ 0 $ 0
Total preferred stock value issued $ 0.0 $ 0.0
NSG | $100 par value, Cumulative Preferred Stock    
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]    
Par or stated value per share $ 100  
Shares authorized 160,000 160,000
Shares outstanding 0 0
Redemption price per share $ 0  
Total preferred stock value issued $ 0.0 $ 0.0
v3.25.4
Short-Term Debt and Lines of Credit - Outstanding Amounts (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
WE    
Short-term Debt [Line Items]    
Maximum debt to capitalization ratio 65.00%  
PGL    
Short-term Debt [Line Items]    
Maximum debt to capitalization ratio 65.00%  
WPS    
Short-term Debt [Line Items]    
Maximum debt to capitalization ratio 65.00%  
WG    
Short-term Debt [Line Items]    
Maximum debt to capitalization ratio 65.00%  
WEC Energy Group    
Short-term Debt [Line Items]    
Commercial paper outstanding $ 702.9 $ 382.7
Maximum debt to capitalization ratio 70.00%  
Commercial paper    
Short-term Debt [Line Items]    
Commercial paper outstanding $ 1,921.3 $ 1,114.4
Average interest rate on amount outstanding 3.89% 4.63%
Average amount outstanding during the year $ 1,124.2  
Weighted- average interest rate during the year 4.43%  
Operating expense loans    
Short-term Debt [Line Items]    
Operating expense loan outstanding $ 3.4 $ 2.2
v3.25.4
Short-Term Debt and Lines of Credit - Credit Facilities (Details)
$ in Millions
12 Months Ended
Dec. 31, 2025
USD ($)
extension
Dec. 31, 2024
USD ($)
Line of Credit Facility [Line Items]    
Short-term credit capacity $ 3,900.0  
Available capacity under existing agreements $ 1,976.4  
Number of extensions available on a credit facility | extension 2  
Length of credit facility extension 1 year  
WE | Credit facility maturing August 2030    
Line of Credit Facility [Line Items]    
Short-term credit capacity $ 800.0  
Number of extensions available on a credit facility | extension 2  
Length of credit facility extension 1 year  
PGL | Credit facility maturing August 2030    
Line of Credit Facility [Line Items]    
Short-term credit capacity $ 600.0  
Number of extensions available on a credit facility | extension 2  
Length of credit facility extension 1 year  
WPS | Credit facility maturing August 2030    
Line of Credit Facility [Line Items]    
Short-term credit capacity $ 450.0  
Number of extensions available on a credit facility | extension 2  
Length of credit facility extension 1 year  
WG | Credit facility maturing August 2030    
Line of Credit Facility [Line Items]    
Short-term credit capacity $ 350.0  
Number of extensions available on a credit facility | extension 2  
Length of credit facility extension 1 year  
WEC Energy Group    
Line of Credit Facility [Line Items]    
Commercial paper outstanding $ 702.9 $ 382.7
WEC Energy Group | Credit facility maturing August 2030    
Line of Credit Facility [Line Items]    
Short-term credit capacity $ 1,700.0  
Number of extensions available on a credit facility | extension 2  
Length of credit facility extension 1 year  
WEC Energy Group | Credit facility maturing October 2025    
Line of Credit Facility [Line Items]    
Short-term credit capacity $ 200.0  
Letter of Credit    
Line of Credit Facility [Line Items]    
Letters of credit issued inside credit facilities 2.3  
Commercial paper    
Line of Credit Facility [Line Items]    
Commercial paper outstanding $ 1,921.3 $ 1,114.4
v3.25.4
Long-Term Debt - Debt Outstanding (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Long-term debt    
Total $ 20,139.9 $ 19,023.9
Long-term debt, including current portion 20,017.5 18,907.1
Unamortized debt issuance costs (110.4) (103.2)
Unamortized discount, net and other (19.5) (21.1)
Current portion of long-term debt (1,519.4) (1,729.0)
Long-term debt $ 18,498.1 $ 17,178.1
WE    
Long-term debt    
Weighted average interest rate 4.55% 4.55%
Unsecured debt $ 4,485.0 $ 3,935.0
WEPCo Environmental Trust Finance I, LLC    
Long-term debt    
Weighted average interest rate 1.58% 1.58%
Secured debt $ 78.8 $ 88.0
WPS    
Long-term debt    
Weighted average interest rate 3.99% 4.17%
Senior notes $ 1,975.0 $ 2,275.0
WG    
Long-term debt    
Weighted average interest rate 4.34% 3.92%
Unsecured debt $ 940.0 $ 840.0
PGL    
Long-term debt    
Weighted average interest rate 3.56% 3.56%
Secured debt $ 1,995.0 $ 1,995.0
PGL | Collateralized First Mortgage Bonds    
Long-term debt    
Secured debt $ 100.0  
NSG    
Long-term debt    
Weighted average interest rate 3.81% 3.81%
Secured debt $ 177.0 $ 177.0
MERC    
Long-term debt    
Weighted average interest rate 3.64% 3.04%
Senior notes $ 210.0 $ 210.0
MGU    
Long-term debt    
Weighted average interest rate 4.38% 3.45%
Senior notes $ 190.0 $ 175.0
UMERC    
Long-term debt    
Weighted average interest rate 4.23% 3.26%
Senior notes $ 280.0 $ 160.0
Bluewater Gas Storage    
Long-term debt    
Weighted average interest rate 4.07% 4.07%
Senior notes $ 128.0 $ 131.9
ATC Holding LLC    
Long-term debt    
Weighted average interest rate 4.02% 4.05%
Senior notes $ 390.0 $ 475.0
We Power    
Long-term debt    
Weighted average interest rate 5.71% 5.67%
Secured debt $ 769.9 $ 814.3
WECC    
Long-term debt    
Weighted average interest rate 6.94% 6.94%
Unsecured debt $ 50.0 $ 50.0
WECI Wind Holding I    
Long-term debt    
Weighted average interest rate 2.75% 2.75%
Senior notes $ 202.1 $ 246.4
WECI Wind Holding II    
Long-term debt    
Weighted average interest rate 6.38% 6.38%
Senior notes $ 147.9 $ 167.6
WECI Energy Holding III    
Long-term debt    
Weighted average interest rate 5.73% 5.73%
Senior notes $ 446.2 $ 488.7
Jayhawk Wind LLC    
Long-term debt    
Long-term debt, including current portion $ 7.5 $ 7.5
WEC Energy Group    
Long-term debt    
Weighted average interest rate 3.96% 4.13%
Senior notes $ 6,325.0 $ 6,045.0
Current portion of long-term debt (1,350.0) (620.0)
Long-term debt $ 6,280.2 $ 6,135.4
WEC Energy Group | Junior Notes    
Long-term debt    
Weighted average interest rate 6.24%  
Unsecured debt $ 1,350.0  
WEC Energy Group | 2024 Junior Notes    
Long-term debt    
Weighted average interest rate   6.72%
Unsecured debt   $ 750.0
WEC Energy Group | 2025 Junior Notes    
Long-term debt    
Interest rate 5.625%  
Minimum required interest rate 5.625%  
WEC Energy Group | 2024A Junior Notes due June 15, 2055    
Long-term debt    
Interest rate 6.69%  
WEC Energy Group | 2024B Junior Notes due June 15, 2055    
Long-term debt    
Interest rate 6.74%  
v3.25.4
Long-Term Debt - Issuances and Redemptions (Details) - USD ($)
$ in Millions
1 Months Ended
Jan. 31, 2026
Dec. 31, 2025
Nov. 30, 2025
Sep. 30, 2025
Aug. 31, 2025
Jun. 30, 2025
May 31, 2025
Apr. 30, 2025
Dec. 31, 2024
WE                  
Long-term debt                  
DOE Federal Loan Guarantee                 $ 2,500.0
3.10% WE Debentures due June 1, 2025 | WE                  
Long-term debt                  
Interest rate           3.10%      
Repayment of long-term debt           $ 250.0      
4.15% $500M WE Debentures due 10/15/2030 | WE                  
Long-term debt                  
Issuance of debt       $ 500.0          
Interest rate       4.15%          
3.95% WE Debentures $300M due March 1, 2029 | WE                  
Long-term debt                  
Issuance of debt   $ 300.0              
Interest rate   3.95%              
WPS 5.35% $300M Senior Notes due November 10, 2025 | WPS                  
Long-term debt                  
Interest rate     5.35%            
Repayment of long-term debt     $ 300.0            
WPS 4.25% $300M Senior Notes due January 15, 2031 | WPS | Subsequent event                  
Long-term debt                  
Issuance of debt $ 300.0                
Interest rate 4.25%                
4.70% $175M WG Debentures due 10/1/2030 | WG                  
Long-term debt                  
Issuance of debt       $ 175.0          
Interest rate       4.70%          
5.39% $125M WG Debentures due 10/1/2035 | WG                  
Long-term debt                  
Issuance of debt       $ 125.0          
Interest rate       5.39%          
3.53% $200M WG Debentures due 09/30/2025 | WG                  
Long-term debt                  
Interest rate       3.53%          
Repayment of long-term debt       $ 200.0          
5.20% MERC Senior Notes due 5/1/2030 | MERC                  
Long-term debt                  
Issuance of debt               $ 50.0  
Interest rate               5.20%  
2.69% MERC Senior Notes due 5/1/2025 | MERC                  
Long-term debt                  
Interest rate             2.69%    
Repayment of long-term debt             $ 50.0    
5.20% MGU Senior Notes due 5/1/2030 | MGU                  
Long-term debt                  
Issuance of debt               $ 75.0  
Interest rate               5.20%  
2.69% MGU Senior Notes due 5/1/2025 | MGU                  
Long-term debt                  
Interest rate             2.69%    
Repayment of long-term debt             $ 60.0    
5.31% $80M UMERC Senior Notes due 8/14/2030 | UMERC                  
Long-term debt                  
Issuance of debt         $ 80.0        
Interest rate         5.31%        
5.93% $40M UMERC Senior Notes due 8/14/2035 | UMERC                  
Long-term debt                  
Issuance of debt         $ 40.0        
Interest rate         5.93%        
4.18% ATC Senior Notes due December 2025 | ATC                  
Long-term debt                  
Interest rate   4.18%              
Repayment of long-term debt   $ 85.0              
WEC Energy Group | WEC 3.55% Senior Notes $120M due June 15, 2025                  
Long-term debt                  
Interest rate           3.55%      
Repayment of long-term debt           $ 120.0      
WEC Energy Group | WEC 5.00% Senior Notes $500M due September 27, 2025                  
Long-term debt                  
Interest rate       5.00%          
Repayment of long-term debt       $ 500.0          
WEC Energy Group | WEC 5.625% $600M Junior Notes due May 15, 2056                  
Long-term debt                  
Issuance of debt     $ 600.0            
Interest rate     5.625%            
WEC Energy Group | WEC 4.75% Senior Notes $1000M due January 9, 2026                  
Long-term debt                  
Interest rate   4.75%              
WEC Energy Group | WEC 4.75% Senior Notes $1000M due January 9, 2026 | Subsequent event                  
Long-term debt                  
Interest rate 4.75%                
Repayment of long-term debt $ 1,000.0                
WEC Energy Group | WEC 3.375% Convertible Notes due June 1, 2028                  
Long-term debt                  
Interest rate           3.375%      
Proceeds from convertible debt           $ 900.0      
v3.25.4
Long-Term Debt - Convertible Debt (Details)
1 Months Ended 3 Months Ended 12 Months Ended
Dec. 31, 2025
USD ($)
$ / shares
Jun. 30, 2025
USD ($)
d
$ / shares
Jun. 30, 2024
USD ($)
d
Dec. 31, 2025
USD ($)
$ / shares
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Long-term debt            
Unamortized debt issuance costs $ 110,400,000     $ 110,400,000 $ 103,200,000  
Net carrying amount 20,017,500,000     20,017,500,000 18,907,100,000  
WEC Energy Group            
Long-term debt            
Senior notes 6,325,000,000     6,325,000,000 6,045,000,000  
Interest expense       399,300,000 333,600,000 $ 260,800,000
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027            
Long-term debt            
Issuance of debt     $ 862,500,000      
Interest rate     4.375%      
Principal amount conversion rate applied to $ 1,000     $ 1,000    
Initial conversion ratio 10.1243          
Initial conversion price. per share | $ / shares $ 98.77     $ 98.77    
Senior notes $ 862,500,000     $ 862,500,000    
Unamortized debt issuance costs (4,700,000)     (4,700,000)    
Net carrying amount 857,800,000     857,800,000    
Fair value amount 977,800,000     977,800,000    
Contractual interest expense       37,700,000 22,300,000  
Amortization of debt issuance costs       3,300,000 1,900,000  
Interest expense       41,000,000.0 24,200,000  
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027 | Early Redemption Terms            
Long-term debt            
Debt instrument, redemption price, percentage     100.00%      
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027 | Debt Conversion Terms One            
Long-term debt            
Threshold percentage of trigger     130.00%      
Trading days | d     20      
Consecutive trading days | d     30      
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027 | Debt Conversion Terms Two            
Long-term debt            
Threshold percentage of trigger     98.00%      
Trading days | d     5      
Consecutive trading days | d     10      
Principal amount conversion rate applied to     $ 1,000      
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027 | Debt Conversion Terms Four            
Long-term debt            
Trading days prior to maturity | d     2      
WEC Energy Group | WEC 3.375% Convertible Notes due June 1, 2028            
Long-term debt            
Interest rate   3.375%        
Principal amount conversion rate applied to   $ 1,000        
Initial conversion ratio   7.7901        
Initial conversion price. per share | $ / shares   $ 128.37        
Senior notes 900,000,000.0     900,000,000.0    
Unamortized debt issuance costs (8,500,000)     (8,500,000)    
Net carrying amount 891,500,000     891,500,000    
Fair value amount 912,600,000     912,600,000    
Contractual interest expense       17,000,000.0 0  
Amortization of debt issuance costs       1,800,000 0  
Interest expense       18,800,000 0  
WEC Energy Group | WEC 3.375% Convertible Notes due June 1, 2028 | Early Redemption Terms            
Long-term debt            
Debt instrument, redemption price, percentage   100.00%        
WEC Energy Group | WEC 3.375% Convertible Notes due June 1, 2028 | Debt Conversion Terms One            
Long-term debt            
Threshold percentage of trigger   130.00%        
Trading days | d   20        
Consecutive trading days | d   30        
WEC Energy Group | WEC 3.375% Convertible Notes due June 1, 2028 | Debt Conversion Terms Two            
Long-term debt            
Threshold percentage of trigger   98.00%        
Trading days | d   5        
Consecutive trading days | d   10        
Principal amount conversion rate applied to   $ 1,000        
WEC Energy Group | WEC 3.375% Convertible Notes due June 1, 2028 | Debt Conversion Terms Three            
Long-term debt            
Trading days prior to redemption | d   2        
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029            
Long-term debt            
Issuance of debt     $ 862,500,000      
Interest rate     4.375%      
Principal amount conversion rate applied to $ 1,000     $ 1,000    
Initial conversion ratio 10.1243          
Initial conversion price. per share | $ / shares $ 98.77     $ 98.77    
Senior notes $ 862,500,000     $ 862,500,000    
Unamortized debt issuance costs (6,800,000)     (6,800,000)    
Net carrying amount 855,700,000     855,700,000    
Fair value amount $ 1,011,700,000     1,011,700,000    
Contractual interest expense       37,700,000 22,300,000  
Amortization of debt issuance costs       2,000,000.0 1,200,000  
Interest expense       $ 39,700,000 $ 23,500,000  
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029 | Early Redemption Terms            
Long-term debt            
Trading days prior to early redemption | d     41      
Threshold percentage of trigger     130.00%      
Trading days | d     20      
Consecutive trading days | d     30      
Debt instrument, redemption price, percentage     100.00%      
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029 | Debt Conversion Terms One            
Long-term debt            
Threshold percentage of trigger     130.00%      
Trading days | d     20      
Consecutive trading days | d     30      
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029 | Debt Conversion Terms Two            
Long-term debt            
Threshold percentage of trigger     98.00%      
Trading days | d     5      
Consecutive trading days | d     10      
Principal amount conversion rate applied to     $ 1,000      
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029 | Debt Conversion Terms Three            
Long-term debt            
Trading days prior to redemption | d     2      
v3.25.4
Long-Term Debt - Maturities of Long-Term Debt (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Long-term debt maturing within one year    
2026 $ 1,519.4  
2027 2,137.3  
2028 3,203.2  
2029 2,943.4  
2030 1,691.9  
Thereafter 8,644.7  
Total $ 20,139.9 $ 19,023.9
WEPCo Environmental Trust Finance I, LLC | WEPCo Environmental Trust Bonds 1.578%, due 2035    
Long-term debt maturing within one year    
Interest rate 1.58%  
Principal amount of secured debt $ 9.3  
Bluewater Gas Storage | 3.76% Bluewater Gas Storage senior notes    
Long-term debt maturing within one year    
Interest rate 3.76%  
Principal amount of senior notes $ 3.1  
Bluewater Gas Storage | 5.41% Bluewater Senior Notes due 11/01/2041    
Long-term debt maturing within one year    
Interest rate 5.41%  
Principal amount of senior notes $ 1.0  
We Power | 4.91% We Power subsidiaries notes - PWGS    
Long-term debt maturing within one year    
Interest rate 4.91%  
Principal amount of secured debt $ 8.9  
We Power | 5.209% We Power subsidiaries notes - ERGS    
Long-term debt maturing within one year    
Interest rate 5.209%  
Principal amount of secured debt $ 17.1  
We Power | 4.673% We Power subsidiaries notes - ERGS    
Long-term debt maturing within one year    
Interest rate 4.673%  
Principal amount of secured debt $ 12.8  
We Power | 6.00% We Power subsidiaries notes - PWGS    
Long-term debt maturing within one year    
Interest rate 6.00%  
Principal amount of secured debt $ 7.9  
WECI Wind Holding I | 2.75% WECI Wind Holding I senior notes due 2032    
Long-term debt maturing within one year    
Interest rate 2.75%  
Principal amount of senior notes $ 45.1  
WECI Wind Holding II | 6.38% WECI Wind Holding II LLC Senior Notes Due 2031    
Long-term debt maturing within one year    
Interest rate 6.38%  
Principal amount of senior notes $ 22.6  
WECI Energy Holding III | 5.73% WECI Energy Holding III LLC Senior Notes Due 12/31/2039    
Long-term debt maturing within one year    
Interest rate 5.73%  
Principal amount of senior notes $ 41.6  
WEC Energy Group    
Long-term debt maturing within one year    
2026 1,350.0  
2027 1,762.5  
2028 1,850.0  
2029 862.5  
2030 300.0  
Thereafter $ 1,550.0  
WEC Energy Group | WEC 4.75% Senior Notes $1000M due January 9, 2026    
Long-term debt maturing within one year    
Interest rate 4.75%  
Principal amount of unsecured debt $ 1,000.0  
WEC Energy Group | 5.60% $350M WEC Senior Notes due September 2026    
Long-term debt maturing within one year    
Interest rate 5.60%  
Principal amount of unsecured debt $ 350.0  
v3.25.4
Leases - Land Leases - Utility Solar Generation (Details) - Land lease - utility solar generation
12 Months Ended
Dec. 31, 2025
renewal_terms
Leases  
Minimum number of contract renewals 1
Minimum  
Leases  
lease term 40 years
Maximum  
Leases  
lease term 50 years
v3.25.4
Leases - Land Leases -Non-Utility Energy Infrastructure Solar Generation (Details) - Land lease - non-utility energy infrastructure solar generation
12 Months Ended
Dec. 31, 2025
renewal_terms
Leases  
Minimum number of contract renewals 1
lease term 50 years
v3.25.4
Leases - Lease Expense and Supplemental Cash Flow Information (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Lease expense      
Amortization of finance lease right of use assets $ 1.1 $ 0.2 $ 0.0
Interest on finance lease liabilities 6.9 1.8 0.8
Operating lease expense 7.8 5.2 4.7
Short-term lease expense 0.2 0.6 1.2
Lease expense 16.0 7.8 6.7
Other information      
Operating cash flows from finance leases 6.4 1.8 0.8
Operating cash flows from operating leases 7.5 7.1 6.8
Financing cash flows from finance leases 0.9 0.0 0.0
Right-of-use asset obtained in exchange for finance lease liabilities 63.8 153.2 32.8
Right of use assets obtained in exchange for operating lease liabilities $ 43.5 $ 2.6 $ 18.3
Weighted average remaining lease term - finance leases 49 years 7 months 6 days 50 years 2 months 12 days 49 years 4 months 24 days
Weighted average remaining lease term - operating leases 35 years 9 months 18 days 25 years 1 month 6 days 22 years 4 months 24 days
Weighted average discount rate - finance leases 6.00% 5.90% 5.30%
Weighted average discount rate - operating leases 6.30% 5.90% 5.80%
v3.25.4
Leases - Finance and Operating Lease Right of Use Assets and Obligations (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Leases    
Operating lease right of use assets $ 69.5 $ 32.1
Finance lease right of use assets 335.5 281.3
Current operating lease liabilities 3.1 4.3
Long-term operating lease liabilities 73.0 37.5
Current finance lease liabilities 0.2  
Long-term finance lease liabilities 372.0 303.3
Accumulated amortization $ 16.3 $ 10.0
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Other Other
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Property, plant, and equipment, net of accumulated depreciation and amortization of $12,411.5 and $11,611.9, respectively Property, plant, and equipment, net of accumulated depreciation and amortization of $12,411.5 and $11,611.9, respectively
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other Other
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Other Other
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other  
Land lease - utility solar generation    
Leases    
Finance lease right of use assets $ 291.5 $ 235.8
Current finance lease liabilities 0.0  
Long-term finance lease liabilities 327.3 257.9
Land lease - non-utility energy infrastructure solar generation    
Leases    
Finance lease right of use assets 42.3 43.5
Current finance lease liabilities 0.0  
Long-term finance lease liabilities 43.3 43.8
Other    
Leases    
Finance lease right of use assets 1.7 2.0
Current finance lease liabilities 0.2 0.2
Long-term finance lease liabilities $ 1.4 $ 1.6
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other Other
v3.25.4
Leases - Future Minimum Lease Payments (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Total operating leases    
2026 $ 7.0  
2027 6.3  
2028 5.2  
2029 5.2  
2030 5.0  
Thereafter 208.2  
Total minimum lease payments 236.9  
Less: interest (160.8)  
Present value of minimum lease payments 76.1  
Less: short-term lease liabilities (3.1) $ (4.3)
Long-term operating lease liabilities 73.0 37.5
Finance leases    
2026 12.0  
2027 16.4  
2028 18.3  
2029 18.6  
2030 19.1  
Thereafter 1,380.1  
Total minimum lease payments 1,464.5  
Less: interest (1,092.3)  
Present value of minimum lease payments 372.2  
Less: short-term lease liabilities (0.2)  
Long-term finance lease liabilities $ 372.0 303.3
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other  
Land lease - utility solar generation    
Finance leases    
2026 $ 9.5  
2027 13.8  
2028 15.9  
2029 16.2  
2030 16.6  
Thereafter 1,221.0  
Total minimum lease payments 1,293.0  
Less: interest (965.7)  
Present value of minimum lease payments 327.3  
Less: short-term lease liabilities 0.0  
Long-term finance lease liabilities 327.3 257.9
Land lease - non-utility energy infrastructure solar generation    
Finance leases    
2026 2.2  
2027 2.3  
2028 2.3  
2029 2.3  
2030 2.4  
Thereafter 156.6  
Total minimum lease payments 168.1  
Less: interest (124.8)  
Present value of minimum lease payments 43.3  
Less: short-term lease liabilities 0.0  
Long-term finance lease liabilities 43.3 43.8
Other    
Finance leases    
2026 0.3  
2027 0.3  
2028 0.1  
2029 0.1  
2030 0.1  
Thereafter 2.5  
Total minimum lease payments 3.4  
Less: interest (1.8)  
Present value of minimum lease payments 1.6  
Less: short-term lease liabilities (0.2) (0.2)
Long-term finance lease liabilities $ 1.4 $ 1.6
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other Other
v3.25.4
Income Taxes - Summary of Income Tax Expense (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income Tax Disclosure [Abstract]      
Current tax benefit- federal $ (242.5) $ (178.5) $ (36.7)
Current tax expense (benefit) - state (8.0) (128.5) 21.9
Deferred tax expense, net - federal 240.9 386.2 130.1
Deferred tax expense, net - state 135.6 152.5 99.8
ITCs, net (8.0) (9.7) (10.5)
Total income tax expense $ 118.0 $ 222.0 $ 204.6
v3.25.4
Income Taxes - Statutory Rate Reconciliation (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Statutory rate reconciliation of amount      
Income before income taxes $ 1,673.5 $ 1,746.3 $ 1,536.3
US federal statutory income tax rate, amount 351.9 367.3 322.6
State and local income taxes net of federal tax effect, amount 101.2 108.0 94.3
Tax credits, amount      
PTCS, net, amount (261.3) (200.1) (168.2)
Other, amount (8.2) (10.0) (10.9)
Nontaxable or nondeductible items, amount      
AFUDC-Equity, amount (21.0) (12.6) (12.4)
Other, amount 11.0 4.0 4.4
Changes in unrecognized tax benefits, amount (2.0) (0.4) (1.8)
Other adjustments, amount      
Federal excess deferred tax amortization, amount (43.0) (36.7) (37.6)
Other, net, amount (10.6) 2.5 14.2
Total income tax expense $ 118.0 $ 222.0 $ 204.6
Statutory rate reconciliation of percent      
US Statutory federal income tax, percent 21.00% 21.00% 21.00%
State and local income taxes net of federal tax effect, percent 6.00% 6.20% 6.10%
Tax credits, percent      
PTCs, net, percent (15.60%) (11.50%) (10.90%)
Other, percent (0.50%) (0.60%) (0.70%)
Nontaxable or nondeductible items, percent      
AFUDC - Equity, percent (1.30%) (0.70%) (0.80%)
Other, percent 0.70% 0.20% 0.20%
Changes in unrecognized tax benefits, percent (0.10%) 0.00% (0.10%)
Other adjustments, percent      
Federal excess deferred tax amortization, percent (2.60%) (2.10%) (2.40%)
Other, net, percent (0.50%) 0.20% 0.90%
Total income tax expense 7.10% 12.70% 13.30%
Public Service Commission of Wisconsin (PSCW) | Tax Cuts and Jobs Act of 2017 | 2018 and 2019 rates      
Income taxes      
Income statement impact of amortizing protected tax benefits $ 0.0 $ 0.0 $ 0.0
v3.25.4
Income Taxes - Components of Deferred Income Taxes (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Deferred Tax Assets    
Tax gross up - regulatory items $ 416.9 $ 420.1
Future tax benefits 240.9 165.4
Deferred revenues 76.8 76.0
Other 206.1 167.9
Total deferred tax assets 940.7 829.4
Valuation allowance (1.1) (1.1)
Net deferred tax assets 939.6 828.3
Deferred Tax Liabilities    
Property-related 5,041.5 4,545.2
Investment in affiliates 1,143.6 1,103.9
Employee benefits and compensation 229.2 231.4
Deferred costs - plant retirements 178.0 194.3
Other 239.0 268.2
Total deferred tax liabilities 6,831.3 6,343.0
Deferred tax liability, net $ 5,891.7 $ 5,514.7
v3.25.4
Income Taxes - Carryforwards (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Income taxes    
Balance carryforwards, gross value $ 685.6 $ 107.5
Balance carryforwards, deferred tax effect 240.9 165.4
Balance carryforwards, valuation allowance (1.1) (1.1)
Federal tax jurisdiction    
Income taxes    
Tax credit carryforwards, gross value 0.0 0.0
Tax credit carryforwards, deferred tax effect 206.5 157.9
Tax credit carryforward, valuation allowance 0.0 0.0
State and local jurisdiction    
Income taxes    
Tax credit carryforwards, gross value 0.0 0.0
Operating loss carryforwards, gross value 685.6 107.5
Tax credit carryforwards, deferred tax effect 0.3 0.3
Operating loss carryforwards, deferred tax effect 34.1 7.2
Tax credit carryforward, valuation allowance 0.0 0.0
Operating loss carryforwards, valuation allowance $ (1.1) $ (1.1)
v3.25.4
Income Taxes - Schedule of Unrecognized Tax Benefits Roll Forward (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Reconciliation of the beginning and ending amount of unrecognized tax benefits      
Balance of unrecognized tax benefits, January 1 $ 4.4 $ 4.6 $ 6.3
Additions for tax positions of prior years 0.1 0.0 0.2
Reductions for tax positions of prior years (1.5) (0.2) (1.9)
Balance of unrecognized tax benefits, December 31 3.0 4.4 $ 4.6
Income Taxes      
Deferred tax assets excluded due to uncertainty in income taxes 0.7 1.0  
Net amount of unrecognized tax benefits having impact on the effective tax rate for continuing operations $ 2.3 $ 3.4  
v3.25.4
Income Taxes - Roll forward of interest accrued on unrecognized tax benefits (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income Tax Disclosure [Abstract]      
Balance as of January 1 $ 0.9 $ 0.6 $ 0.5
Interest expense (income) related to unrecognized tax benefits (0.6) 0.3 0.1
Balance as of December 31 0.3 0.9 0.6
Penalties in the consolidated income statements 0.0 0.0 $ 0.0
Accrued penalties on the consolidated balance sheets $ 0.0 $ 0.0  
v3.25.4
Income Taxes - Cash Paid (Received) for Income Taxes, Net (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income taxes paid (received) by jurisdiction, net      
Federal $ (256.3) $ (265.0) $ (75.0)
State (25.0) 0.8 16.1
Total income taxes received, net (281.3) (264.2) (58.9)
PTCs sold to third parties 256.3 269.1 75.0
Wisconsin      
Income taxes paid (received) by jurisdiction, net      
State $ (25.0) $ 0.0 $ 12.0
v3.25.4
Fair Value Measurements - Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Assets    
Derivative assets $ 26.3 $ 41.1
Liabilities    
Derivative liabilities 32.5 13.9
Fair value measurements on a recurring basis    
Assets    
Derivative assets 26.3 41.1
Investments held in rabbi trust 42.0 52.1
Liabilities    
Derivative liabilities 32.5  
Fair value measurements on a recurring basis | Level 1    
Assets    
Derivative assets 1.5 19.6
Investments held in rabbi trust 42.0 52.1
Liabilities    
Derivative liabilities 23.3  
Fair value measurements on a recurring basis | Level 2    
Assets    
Derivative assets 18.3 13.7
Investments held in rabbi trust 0.0 0.0
Liabilities    
Derivative liabilities 8.4  
Fair value measurements on a recurring basis | Level 3    
Assets    
Derivative assets 6.5 7.8
Investments held in rabbi trust 0.0 0.0
Liabilities    
Derivative liabilities 0.8  
Fair value measurements on a recurring basis | Natural gas contracts    
Assets    
Derivative assets 19.8 33.3
Liabilities    
Derivative liabilities 31.7 13.9
Fair value measurements on a recurring basis | Natural gas contracts | Level 1    
Assets    
Derivative assets 1.5 19.6
Liabilities    
Derivative liabilities 23.3 7.1
Fair value measurements on a recurring basis | Natural gas contracts | Level 2    
Assets    
Derivative assets 18.3 13.7
Liabilities    
Derivative liabilities 8.4 6.8
Fair value measurements on a recurring basis | Natural gas contracts | Level 3    
Assets    
Derivative assets 0.0 0.0
Liabilities    
Derivative liabilities 0.0 0.0
Fair value measurements on a recurring basis | FTRs and TCRs    
Assets    
Derivative assets 6.5 7.8
Liabilities    
Derivative liabilities 0.8  
Fair value measurements on a recurring basis | FTRs and TCRs | Level 1    
Assets    
Derivative assets 0.0 0.0
Liabilities    
Derivative liabilities 0.0  
Fair value measurements on a recurring basis | FTRs and TCRs | Level 2    
Assets    
Derivative assets 0.0 0.0
Liabilities    
Derivative liabilities 0.0  
Fair value measurements on a recurring basis | FTRs and TCRs | Level 3    
Assets    
Derivative assets 6.5 $ 7.8
Liabilities    
Derivative liabilities $ 0.8  
v3.25.4
Fair Value Measurements - Net Unrealized Gains (Losses) on Investments Still Held (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Fair Value Disclosures [Abstract]      
Net unrealized gains in earnings related to investments held at the end of the period $ 5.8 $ 9.0 $ 10.0
v3.25.4
Fair Value Measurements - Level 3 Reconciliation (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Level 3 rollforward      
Balance at the beginning of the period $ 7.8 $ 7.2 $ 7.8
Purchases 23.7 28.7 21.0
Net realized and unrealized losses included in earnings 0.0 (0.7) (0.5)
Sales (1.0) 0.0 0.0
Settlements (24.8) (27.4) (21.1)
Balance at the end of period 5.7 7.8 7.2
Net unrealized gains included in earnings attributable to level 3 derivatives held at the end of the reporting period $ 0.1 $ 0.0 $ 0.5
v3.25.4
Fair Value Measurements - Financial Instruments (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Financial instruments    
Preferred stock of subsidiary $ 30.4 $ 30.4
Long-term debt, including current portion 20,017.5 18,907.1
Carrying amount    
Financial instruments    
Preferred stock of subsidiary 30.4 30.4
Long-term debt, including current portion 20,017.5 18,907.1
Fair value    
Financial instruments    
Preferred stock of subsidiary 21.2 21.2
Long-term debt, including current portion $ 19,609.1 $ 17,840.8
v3.25.4
Derivative Instruments - Derivative Assets and Liabilities (Details)
$ in Millions
Dec. 31, 2025
USD ($)
Instruments
Dec. 31, 2024
USD ($)
Instruments
Derivative assets    
Current derivative assets $ 26.2 $ 37.0
Total derivative assets $ 26.3 $ 41.1
Current derivative assets balance sheet location Other Other
Total derivative assets balance sheet location Total assets Total assets
Derivative liabilities    
Current derivative liabilities $ 30.8 $ 13.9
Total derivative liabilities $ 32.5 $ 13.9
Current derivative liabilities balance sheet location Other Other
Total derivative liabilities balance sheet location Total liabilities and equity Total liabilities and equity
Natural gas contracts    
Derivative assets    
Current derivative assets $ 19.7 $ 29.2
Long-term derivative assets $ 0.1 $ 4.1
Long-term derivative assets balance sheet location Other Other
Derivative liabilities    
Current derivative liabilities $ 30.0 $ 13.9
Long-term derivative Iiabilities $ 1.7 $ 0.0
Long-term derivative liabilities balance sheet location Other Other
FTRs and TCRs    
Derivative assets    
Current derivative assets $ 6.5 $ 7.8
Derivative liabilities    
Current derivative liabilities $ 0.8 $ 0.0
Hedging instruments    
Derivative instruments    
Number of derivatives designated as hedging instruments | Instruments 0 0
v3.25.4
Derivative Instruments - Gains (Losses) and Notional Volumes (Details)
MWh in Millions, MMBTU in Millions, $ in Millions
12 Months Ended
Dec. 31, 2025
USD ($)
MMBTU
MWh
Dec. 31, 2024
USD ($)
MMBTU
MWh
Dec. 31, 2023
USD ($)
MWh
MMBTU
Realized gains (losses) on derivatives      
Gains (losses) $ (0.4) $ (119.6) $ (233.2)
Natural gas contracts | Public utilities      
Realized gains (losses) on derivatives      
Gains (losses) $ (19.2) $ (127.8) $ (259.1)
Realized gains and losses on derivatives income statement location Cost of sales Cost of sales Cost of sales
Notional volumes      
Notional volumes | MMBTU 202.4 206.3 198.0
FTRs and TCRs | Non-Utility Energy Infrastructure      
Realized gains (losses) on derivatives      
Gains (losses) $ (0.1) $ (0.1) $ (1.5)
Realized gains and losses on derivatives income statement location Revenues Revenues Revenues
Notional volumes      
Notional volumes | MWh 0.7 1.3 0.9
FTRs and TCRs | Public utilities      
Realized gains (losses) on derivatives      
Gains (losses) $ 18.9 $ 8.3 $ 27.4
Realized gains and losses on derivatives income statement location Cost of sales Cost of sales Cost of sales
Notional volumes      
Notional volumes | MWh 26.3 28.4 29.3
v3.25.4
Derivative Instruments - Balance Sheet Offsetting (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Cash collateral    
Cash collateral posted $ 41.4 $ 16.0
Cash collateral received   4.2
Offsetting derivative assets    
Gross amount recognized on the balance sheet 26.3 41.1
Gross amount not offset on the balance sheet (2.0) (11.5)
Net amount 24.3 29.6
Cash collateral received   4.2
Offsetting derivative liabilities    
Gross amount recognized on the balance sheet 32.5 13.9
Gross amount not offset on the balance sheet (23.8) (7.3)
Net amount 8.7 $ 6.6
Cash collateral posted $ 21.8  
v3.25.4
Guarantees (Details)
$ in Millions
Dec. 31, 2025
USD ($)
Guarantor Obligations  
Total guarantees $ 244.3
Guarantees expiring in less than one year 77.1
Guarantees expiring within one to three years 30.3
Guarantees with expiration over three years 136.9
Standby letters of credit  
Guarantor Obligations  
Total guarantees 188.2
Guarantees expiring in less than one year 30.7
Guarantees expiring within one to three years 30.2
Guarantees with expiration over three years 127.3
Surety bonds  
Guarantor Obligations  
Total guarantees 46.5
Guarantees expiring in less than one year 46.4
Guarantees expiring within one to three years 0.1
Guarantees with expiration over three years 0.0
Other guarantees  
Guarantor Obligations  
Total guarantees 9.6
Guarantees expiring in less than one year 0.0
Guarantees expiring within one to three years 0.0
Guarantees with expiration over three years $ 9.6
v3.25.4
Employee Benefits - Change in Benefit Obligations and Plan Assets (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Pension Benefits      
Change in benefit obligation      
Obligation at January 1 $ 2,209.2 $ 2,352.4  
Service cost 20.8 24.2 $ 24.0
Interest cost 118.6 116.6 122.3
Participant contributions 0.0 0.0  
Plan amendments 0.0 0.0  
Actuarial (gain) loss 8.2 (99.6)  
Benefit payments (193.7) (184.4)  
Transfer 0.0 0.0  
Obligation at December 31 2,163.1 2,209.2 2,352.4
Change in fair value of plan assets      
Beginning balance at January 1 2,624.3 2,665.8  
Actual return on plan assets 221.6 129.8  
Employer contributions net of plan transfer 11.8 13.1  
Participant contributions 0.0 0.0  
Benefit payments (193.7) (184.4)  
Ending balance at December 31 2,664.0 2,624.3 2,665.8
Funded status at December 31 500.9 415.1  
OPEB Benefits      
Change in benefit obligation      
Obligation at January 1 460.9 448.1  
Service cost 11.3 10.9 9.8
Interest cost 25.7 22.7 21.6
Participant contributions 11.5 11.2  
Plan amendments (0.4) 0.0  
Actuarial (gain) loss 28.3 6.9  
Benefit payments (46.8) (41.7)  
Federal subsidy on benefits paid 1.4 1.4  
Transfer 1.5 1.4  
Obligation at December 31 493.4 460.9 448.1
Change in fair value of plan assets      
Beginning balance at January 1 850.0 829.6  
Actual return on plan assets 87.9 49.5  
Employer contributions net of plan transfer 1.9 1.4  
Participant contributions 11.5 11.2  
Benefit payments (46.8) (41.7)  
Ending balance at December 31 904.5 850.0 $ 829.6
Funded status at December 31 $ 411.1 $ 389.1  
v3.25.4
Employee Benefits - Amounts Recognized on the Balance Sheets (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Defined Benefit Plan Disclosure [Line Items]    
Pension and OPEB assets $ 1,082.4 $ 968.5
Pension Benefits    
Defined Benefit Plan Disclosure [Line Items]    
Pension and OPEB assets 646.3 562.4
Other long-term liabilities 145.4 147.3
Total net assets 500.9 415.1
OPEB Benefits    
Defined Benefit Plan Disclosure [Line Items]    
Pension and OPEB assets 436.1 406.1
Other long-term liabilities 25.0 17.0
Total net assets $ 411.1 $ 389.1
v3.25.4
Employee Benefits - Accumulated Benefit Obligations (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Pension Plan    
Defined Benefit Plan Disclosure [Line Items]    
Accumulated benefit obligation $ 2,112.5 $ 2,156.8
Information for pension or OPEB plans with an accumulated benefit obligation in excess of plan assets    
Accumulated benefit obligation 283.0 286.0
Fair value of plan assets 141.7 143.2
Information for pension plans with a projected benefit obligation in excess of plan assets    
Projected benefit obligation 287.1 290.5
Fair value of plan assets 141.7 143.2
OPEB Benefits    
Information for pension or OPEB plans with an accumulated benefit obligation in excess of plan assets    
Accumulated benefit obligation 205.5 194.0
Fair value of plan assets $ 180.5 $ 177.0
v3.25.4
Employee Benefits - Amounts Not Yet Recognized in Net Periodic Benefit Cost (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Pension Benefits    
Pre-tax accumulated other comprehensive income (loss)    
Net actuarial loss (gain) $ 11.6 $ 12.3
Net regulatory assets (liabilities)    
Net actuarial loss (gain) 501.1 578.7
Prior service credits (2.0) (2.1)
Total 499.1 576.6
OPEB Benefits    
Pre-tax accumulated other comprehensive income (loss)    
Net actuarial loss (gain) (1.0) (1.1)
Net regulatory assets (liabilities)    
Net actuarial loss (gain) (146.1) (148.8)
Prior service credits (8.4) (15.8)
Total $ (154.5) $ (164.6)
v3.25.4
Employee Benefits - Net Periodic Benefit Cost (Credit) (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Components of net periodic benefit cost (credit) (including amounts capitalized to the balance sheets)      
Regulatory asset $ 3,173.6 $ 3,378.7  
Regulatory liability 4,210.2 4,003.3  
Pension Benefits      
Components of net periodic benefit cost (credit) (including amounts capitalized to the balance sheets)      
Service cost 20.8 24.2 $ 24.0
Interest cost 118.6 116.6 122.3
Expected return on plan assets (175.1) (182.1) (187.4)
Plan settlement (1.2) 4.0 1.3
Amortization of prior service cost (credit) (0.1) (0.1) 0.0
Amortization of net actuarial loss (gain) 41.1 59.5 33.0
Net periodic benefit cost (credit) 4.1 22.1 (6.8)
Pension Benefits | Pension and Other Postretirement Plans Cost      
Components of net periodic benefit cost (credit) (including amounts capitalized to the balance sheets)      
Regulatory liability 14.7    
Pension Benefits | Pension and Other Postretirement Plans Cost      
Components of net periodic benefit cost (credit) (including amounts capitalized to the balance sheets)      
Regulatory asset   24.9  
OPEB Benefits      
Components of net periodic benefit cost (credit) (including amounts capitalized to the balance sheets)      
Service cost 11.3 10.9 9.8
Interest cost 25.7 22.7 21.6
Expected return on plan assets (54.3) (52.7) (53.0)
Plan settlement 0.0 0.0 0.0
Amortization of prior service cost (credit) (7.8) (13.5) (14.8)
Amortization of net actuarial loss (gain) (8.2) (7.6) (12.3)
Net periodic benefit cost (credit) (33.3) (40.2) $ (48.7)
OPEB Benefits | Pension and Other Postretirement Plans Cost      
Components of net periodic benefit cost (credit) (including amounts capitalized to the balance sheets)      
Regulatory asset $ 0.7 $ 38.2  
v3.25.4
Employee Benefits - Assumptions (Details)
12 Months Ended
Dec. 31, 2026
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Pension Plan | Benefit obligation assumptions        
Weighted average assumptions - benefit obligations        
Discount rate   5.50% 5.69% 5.19%
Rate of compensation increase   4.00% 4.00%  
Interest credit rate   4.83% 4.85%  
Pension Plan | Net periodic benefit cost assumptions        
Weighted average assumptions - net periodic benefit cost        
Discount rate   5.69% 5.18% 5.49%
Expected return on plan assets   6.61% 6.61% 6.62%
Rate of compensation increase   4.00% 4.00% 4.00%
Interest credit rate   4.85% 4.84% 4.62%
Pension Plan | Net periodic benefit cost assumptions | Subsequent event        
Weighted average assumptions - net periodic benefit cost        
Expected return on plan assets 6.61%      
OPEB Plan | Benefit obligation assumptions        
Weighted average assumptions - benefit obligations        
Discount rate   5.54% 5.71% 5.16%
OPEB Plan | Benefit obligation assumptions | Pre 65        
Medical cost trend rates        
Assumed medical cost trend rate   8.00% 7.00%  
Ultimate trend rate   5.00% 5.00%  
Year ultimate trend rate is reached   2032 2033  
OPEB Plan | Benefit obligation assumptions | Post 65        
Medical cost trend rates        
Assumed medical cost trend rate   9.92% 6.10%  
Ultimate trend rate   5.00% 5.00%  
Year ultimate trend rate is reached   2034 2030  
OPEB Plan | Net periodic benefit cost assumptions        
Weighted average assumptions - net periodic benefit cost        
Discount rate   5.71% 5.16% 5.50%
Expected return on plan assets   6.50% 6.50% 6.50%
OPEB Plan | Net periodic benefit cost assumptions | Subsequent event        
Weighted average assumptions - net periodic benefit cost        
Expected return on plan assets 6.50%      
OPEB Plan | Net periodic benefit cost assumptions | Pre 65        
Medical cost trend rates        
Assumed medical cost trend rate   7.00% 6.25% 6.50%
Ultimate trend rate   5.00% 5.00% 5.00%
Year ultimate trend rate is reached   2033 2031 2031
OPEB Plan | Net periodic benefit cost assumptions | Post 65        
Medical cost trend rates        
Assumed medical cost trend rate   6.10% 6.39% 6.00%
Ultimate trend rate   5.00% 5.00% 5.00%
Year ultimate trend rate is reached   2030 2030 2031
v3.25.4
Employee Benefits - Target Asset Allocations (Details)
Dec. 31, 2025
Pension Plan | Wisconsin Energy Corporation | Equity securities  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 25.00%
Pension Plan | Wisconsin Energy Corporation | Fixed income securities  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 55.00%
Pension Plan | Wisconsin Energy Corporation | Private equity and real estate  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 20.00%
Pension Plan | Integrys | Equity securities  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 25.00%
Pension Plan | Integrys | Fixed income securities  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 55.00%
Pension Plan | Integrys | Private equity and real estate  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 20.00%
OPEB Plan | Wisconsin Energy Corporation | Equity securities  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 45.00%
OPEB Plan | Wisconsin Energy Corporation | Fixed income securities  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 45.00%
OPEB Plan | Wisconsin Energy Corporation | Real estate investments  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 10.00%
OPEB Plan | Integrys | Largest trust 1 | Equity securities  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 45.00%
OPEB Plan | Integrys | Largest trust 1 | Fixed income securities  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 45.00%
OPEB Plan | Integrys | Largest trust 1 | Real estate investments  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 10.00%
OPEB Plan | Integrys | Largest trust 2 | Equity securities  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 45.00%
OPEB Plan | Integrys | Largest trust 2 | Fixed income securities  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 45.00%
OPEB Plan | Integrys | Largest trust 2 | Real estate investments  
Defined Benefit Plan Disclosure [Line Items]  
Target asset allocations (as a percent) 10.00%
v3.25.4
Employee Benefits - Plan Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Pension Plan      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets $ 2,664.0 $ 2,624.3 $ 2,665.8
Pension Plan | Level 1, 2, and 3      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1,332.9 1,288.3  
Pension Plan | Level 1, 2, and 3 | United States equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 160.8 168.4  
Pension Plan | Level 1, 2, and 3 | International equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 173.7 158.2  
Pension Plan | Level 1, 2, and 3 | United States bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 934.9 880.1  
Pension Plan | Level 1, 2, and 3 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 63.5 81.6  
Pension Plan | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 334.5 326.6  
Pension Plan | Level 1 | United States equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 160.8 168.4  
Pension Plan | Level 1 | International equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 173.7 158.2  
Pension Plan | Level 1 | United States bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
Pension Plan | Level 1 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
Pension Plan | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 997.0 961.7  
Pension Plan | Level 2 | United States equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
Pension Plan | Level 2 | International equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
Pension Plan | Level 2 | United States bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 933.5 880.1  
Pension Plan | Level 2 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 63.5 81.6  
Pension Plan | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1.4 0.0  
Pension Plan | Level 3 | United States equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
Pension Plan | Level 3 | International equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
Pension Plan | Level 3 | United States bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1.4 0.0  
Pension Plan | Level 3 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
Pension Plan | Investments measured at net asset value per share | Equity securities      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 412.6 414.9  
Pension Plan | Investments measured at net asset value per share | Fixed income securities      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 127.6 126.0  
Pension Plan | Investments measured at net asset value per share | Other investments      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 790.9 795.1  
OPEB Plan      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 904.5 850.0 $ 829.6
OPEB Plan | Level 1, 2, and 3      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 535.8 496.0  
OPEB Plan | Level 1, 2, and 3 | United States equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 97.3 93.8  
OPEB Plan | Level 1, 2, and 3 | International equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 100.8 86.4  
OPEB Plan | Level 1, 2, and 3 | United States bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 330.0 304.6  
OPEB Plan | Level 1, 2, and 3 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 7.7 11.2  
OPEB Plan | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 308.7 279.2  
OPEB Plan | Level 1 | United States equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 97.3 93.8  
OPEB Plan | Level 1 | International equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 100.8 86.4  
OPEB Plan | Level 1 | United States bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 110.6 99.0  
OPEB Plan | Level 1 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
OPEB Plan | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 227.0 216.8  
OPEB Plan | Level 2 | United States equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
OPEB Plan | Level 2 | International equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
OPEB Plan | Level 2 | United States bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 219.3 205.6  
OPEB Plan | Level 2 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 7.7 11.2  
OPEB Plan | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.1 0.0  
OPEB Plan | Level 3 | United States equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
OPEB Plan | Level 3 | International equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
OPEB Plan | Level 3 | United States bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.1 0.0  
OPEB Plan | Level 3 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.0 0.0  
OPEB Plan | Investments measured at net asset value per share | Equity securities      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 206.0 190.4  
OPEB Plan | Investments measured at net asset value per share | Fixed income securities      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 55.3 51.8  
OPEB Plan | Investments measured at net asset value per share | Other investments      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets $ 107.4 $ 111.8  
v3.25.4
Employee Benefits - Reconciliation of Level 3 plan assets (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets $ 2,664.0 $ 2,624.3 $ 2,665.8
Pension Benefits | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1.4 0.0  
Pension Benefits | Level 3 | United States bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 1.4 0.0  
Purchases 1.4    
OPEB Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 904.5 850.0 $ 829.6
OPEB Benefits | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.1 0.0  
OPEB Benefits | Level 3 | United States bonds      
Defined Benefit Plan Disclosure [Line Items]      
Fair Value of Plan Assets 0.1 $ 0.0  
Purchases $ 0.1    
v3.25.4
Employee Benefits - Cash Flows (Details)
$ in Millions
Dec. 31, 2025
USD ($)
Pension Benefits  
Defined Benefit Plan Disclosure [Line Items]  
Expected contributions to the plans during the next year $ 16.5
2026 213.5
2027 203.1
2028 193.5
2029 187.5
2030 182.1
2031-2035 801.3
OPEB Benefits  
Defined Benefit Plan Disclosure [Line Items]  
Expected contributions to the plans during the next year 2.8
2026 35.5
2027 37.6
2028 38.7
2029 39.5
2030 39.8
2031-2035 $ 197.8
v3.25.4
Employee Benefits - Defined Contribution Benefit Plans (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Retirement Benefits [Abstract]      
Total costs incurred for defined contribution benefit plans $ 67.3 $ 61.6 $ 57.5
v3.25.4
Investment in Transmission Affiliates - Changes to Investment (Details)
$ in Millions
12 Months Ended
Dec. 31, 2025
USD ($)
vote
member
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Changes to investment in transmission affiliates      
Investment in transmission affiliates, balance at beginning of period $ 2,191.6 $ 2,081.6  
Add: Capital contributions 142.4 45.5 $ 63.7
Investment in transmission affiliates, balance at end of period 2,353.9 2,191.6 2,081.6
Transmission affiliates      
Changes to investment in transmission affiliates      
Investment in transmission affiliates, balance at beginning of period 2,108.9 2,005.9 1,909.2
Earnings (losses) from equity method investments 215.8 207.5 177.5
Add: Capital contributions 142.4 45.5 63.7
Less: Distributions 186.6 150.1 144.5
Add (Less): Other (0.1) 0.1  
Investment in transmission affiliates, balance at end of period $ 2,280.4 2,108.9 2,005.9
ATC      
Investment in transmission affiliates      
Equity method investment, ownership interest (as a percent) 60.00%    
Total number of members on the transmission affiliate's board of directors | member 11    
Number of representatives on the transmission affiliate's board of directors | member 1    
Number of votes that can be placed by each member on the transmission affiliate's board of directors | vote 1    
Changes to investment in transmission affiliates      
Investment in transmission affiliates, balance at beginning of period $ 2,085.1 1,980.8 1,884.6
Earnings (losses) from equity method investments 209.7 205.4 175.1
Add: Capital contributions 142.4 45.5 63.7
Less: Distributions 180.2 146.7 142.6
Add (Less): Other (0.1) 0.1  
Investment in transmission affiliates, balance at end of period $ 2,256.9 2,085.1 1,980.8
ATC Holdco      
Investment in transmission affiliates      
Equity method investment, ownership interest (as a percent) 75.00%    
Total number of members on the transmission affiliate's board of directors | member 4    
Number of representatives on the transmission affiliate's board of directors | member 1    
Number of votes that can be placed by each member on the transmission affiliate's board of directors | vote 1    
Changes to investment in transmission affiliates      
Investment in transmission affiliates, balance at beginning of period $ 23.8 25.1 24.6
Earnings (losses) from equity method investments 6.1 2.1 2.4
Add: Capital contributions 0.0 0.0 0.0
Less: Distributions 6.4 3.4 1.9
Add (Less): Other 0.0 0.0  
Investment in transmission affiliates, balance at end of period $ 23.5 $ 23.8 $ 25.1
v3.25.4
Investment in Transmission Affiliates - ATC Return on Equity (Details) - ATC - USD ($)
$ in Millions
1 Months Ended 12 Months Ended
Oct. 31, 2024
Aug. 31, 2022
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Allowed return on equity for American Transmission Company LLC          
Earnings (losses) from equity method investments     $ 209.7 $ 205.4 $ 175.1
Opinion issued by United States Court of Appeals for the District of Columbia Circuit in August 2022          
Allowed return on equity for American Transmission Company LLC          
Assumed return on equity (as a percent)   9.88%      
Order issued by the Federal Energy Regulatory Commission in October 2024          
Allowed return on equity for American Transmission Company LLC          
Approved return on equity (as a percent) 9.98%        
Earnings (losses) from equity method investments       $ 20.1  
v3.25.4
Investment in Transmission Affiliates - Related Party Transactions (Details) - ATC - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Investment in transmission affiliates      
Charges to ATC for services and construction $ 20.2 $ 21.6 $ 17.4
Charges from ATC for network transmission services 466.9 413.3 377.5
Refund from ATC related to FERC ROE orders $ 5.2 $ 0.0 $ 0.0
v3.25.4
Investment in Transmission Affiliates - Receivables and Payables (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Investment in transmission affiliates    
Accounts payable for services received from ATC $ 1,140.1 $ 1,137.1
ATC    
Investment in transmission affiliates    
Accounts receivable for services provided to ATC 1.6 1.4
Accounts payable for services received from ATC 38.4 34.4
Amounts due from ATC for transmission infrastructure upgrades $ 32.2 $ 54.5
v3.25.4
Investment in Transmission Affiliates - ATC Summarized Financial Data (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Summarized financial data      
Operating revenues $ 9,800.1 $ 8,599.9 $ 8,893.0
Operating expenses 7,555.2 6,447.1 6,985.0
Other expense, net 571.4 406.5 371.7
Current assets 3,284.7 2,911.7  
Noncurrent assets 48,233.6 44,451.5  
Total assets 51,518.3 47,363.2 43,939.7
Current liabilities 5,593.4 4,841.9  
Long-term debt 18,498.1 17,178.1  
Other noncurrent liabilities 963.4 838.1  
Total liabilities and equity 51,518.3 47,363.2  
ATC      
Summarized financial data      
Operating revenues 975.0 911.3 818.9
Operating expenses 472.6 442.4 407.6
Other expense, net 165.8 137.7 131.7
Net income 336.6 331.2 $ 279.6
Current assets 137.5 126.6  
Noncurrent assets 7,590.8 6,792.6  
Total assets 7,728.3 6,919.2  
Current liabilities 839.8 482.4  
Long-term debt 3,156.3 3,083.4  
Other noncurrent liabilities 638.9 545.0  
Members' equity 3,093.3 2,808.4  
Total liabilities and equity $ 7,728.3 $ 6,919.2  
v3.25.4
Segment Information (Details)
$ in Millions
12 Months Ended
Dec. 31, 2025
USD ($)
numberOfSegments
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Segment information        
Number of reportable segments | numberOfSegments 6      
Operating revenues $ 9,800.1 $ 8,599.9 $ 8,893.0  
Fuel and purchased power 1,674.9 1,455.7 1,615.9  
Cost of natural gas sold 1,590.9 1,200.3 1,575.3  
Other operation and maintenance 2,400.8 2,158.0 2,100.5  
Impairments related to Illinois segment 130.0 12.1 178.9  
Depreciation and amortization 1,478.5 1,354.5 1,264.2  
Property and revenue taxes 280.1 266.5 250.2  
Equity in earnings of transmission affiliates 215.8 207.5 177.5  
Other income, net 107.9 178.2 177.7  
Interest expense 895.1 815.3 727.4  
Gain on debt extinguishments 0.0 (23.1) (0.5)  
Income tax expense (benefit) 118.0 222.0 204.6  
Preferred stock dividends of subsidiary 1.2 1.2 1.2  
Net loss attributed to noncontrolling interests 3.2 4.1 1.2  
Net income (loss) attributed to common shareholders 1,557.5 1,527.2 1,331.7  
Capital expenditures and asset acquisitions 4,804.2 3,774.8 3,507.9  
Equity method investments 2,353.9 2,191.6 2,081.6  
Total assets 51,518.3 47,363.2 43,939.7  
Reconciling eliminations        
Segment information        
Fuel and purchased power 0.0 0.0 0.0  
Cost of natural gas sold (44.5) (46.0) (60.1)  
Other operation and maintenance (9.2) (9.1) (9.1)  
Impairments related to Illinois segment 0.0 0.0 0.0  
Depreciation and amortization (100.9) (88.5) (77.5)  
Property and revenue taxes 0.0 0.0 0.0  
Equity in earnings of transmission affiliates 0.0 0.0 0.0  
Other income, net (31.0) (31.7) (20.5)  
Interest expense (353.1) (362.2) (350.2)  
Gain on debt extinguishments   0.0 0.0  
Income tax expense (benefit) 0.0 0.0 0.0  
Preferred stock dividends of subsidiary 0.0 0.0 0.0  
Net loss attributed to noncontrolling interests 0.0 0.0 0.0  
Net income (loss) attributed to common shareholders 0.0 0.0 0.0  
Capital expenditures and asset acquisitions 0.0 0.0 0.0  
Equity method investments 0.0 0.0 0.0  
Total assets (3,640.7) (3,553.6) (3,640.1)  
Reconciling eliminations | WE        
Segment information        
Total assets 2,594.8 1,525.4 1,630.6  
Wisconsin | Operating segments        
Segment information        
Operating revenues 7,295.5 6,330.5 6,625.9  
Illinois        
Segment information        
Impairments related to Illinois segment 130.0 12.1 178.9  
Illinois | Operating segments        
Segment information        
Operating revenues 1,683.6 1,602.4 1,557.8  
Other States | Operating segments        
Segment information        
Operating revenues 527.5 449.8 519.1  
Electric transmission | Operating segments        
Segment information        
Fuel and purchased power 0.0 0.0 0.0  
Cost of natural gas sold 0.0 0.0 0.0  
Other operation and maintenance 0.0 0.0 0.0  
Impairments related to Illinois segment 0.0 0.0 0.0  
Depreciation and amortization 0.0 0.0 0.0  
Property and revenue taxes 0.0 0.0 0.0  
Equity in earnings of transmission affiliates 215.8 207.5 177.5  
Other income, net 0.0 0.0 0.0  
Interest expense 19.3 19.4 19.4  
Gain on debt extinguishments   0.0 0.0  
Income tax expense (benefit) 48.9 47.1 39.0  
Preferred stock dividends of subsidiary 0.0 0.0 0.0  
Net loss attributed to noncontrolling interests 0.0 0.0 0.0  
Net income (loss) attributed to common shareholders 147.6 141.0 119.1  
Capital expenditures and asset acquisitions 0.0 0.0 0.0  
Equity method investments 2,280.4 2,108.9 2,005.9  
Total assets $ 2,282.8 2,126.0 2,006.0  
Non-Utility Energy Infrastructure        
Segment information        
Natural gas storage needs provided to Wisconsin utilities 33.00%      
Non-Utility Energy Infrastructure | Operating segments        
Segment information        
Operating revenues $ 770.2 691.3 666.5  
Fuel and purchased power 0.0 0.0 0.0  
Cost of natural gas sold 9.6 9.1 20.5  
Other operation and maintenance 95.5 75.1 80.1  
Impairments related to Illinois segment 0.0 0.0 0.0  
Depreciation and amortization 240.2 198.4 188.7  
Property and revenue taxes 19.6 15.7 16.5  
Equity in earnings of transmission affiliates 0.0 0.0 0.0  
Other income, net 2.8 1.0 0.0  
Interest expense 123.1 99.7 94.3  
Gain on debt extinguishments   0.0 0.0  
Income tax expense (benefit) (122.9) (82.4) (68.4)  
Preferred stock dividends of subsidiary 0.0 0.0 0.0  
Net loss attributed to noncontrolling interests 3.2 4.1 1.2  
Net income (loss) attributed to common shareholders 411.1 380.8 336.0  
Capital expenditures and asset acquisitions 504.7 945.8 754.4  
Equity method investments 0.0 0.0 0.0  
Total assets 7,762.9 7,316.0 6,404.7  
Corporate and other | Operating segments        
Segment information        
Operating revenues 0.0 0.0 0.1  
Fuel and purchased power 0.0 0.0 0.0  
Cost of natural gas sold 0.0 0.0 0.0  
Other operation and maintenance (10.2) (11.3) 5.8  
Impairments related to Illinois segment 0.0 0.0 0.0  
Depreciation and amortization 21.6 22.3 20.9  
Property and revenue taxes 0.1 0.3 0.2  
Equity in earnings of transmission affiliates 0.0 0.0 0.0  
Other income, net 30.6 54.4 53.3  
Interest expense 359.0 310.0 258.1  
Gain on debt extinguishments   (23.1) (0.5)  
Income tax expense (benefit) (101.0) (79.5) (68.3)  
Preferred stock dividends of subsidiary 0.0 0.0 0.0  
Net loss attributed to noncontrolling interests 0.0 0.0 0.0  
Net income (loss) attributed to common shareholders (238.9) (164.3) (162.8)  
Capital expenditures and asset acquisitions 20.8 20.6 25.8  
Equity method investments 55.7 67.0 61.3  
Total assets 1,227.6 1,037.3 1,100.1  
Public utilities        
Segment information        
Fuel and purchased power 1,674.9 1,455.7 1,615.9  
Cost of natural gas sold 1,625.8 1,237.2 1,614.9  
Other operation and maintenance 2,324.7 2,103.3 2,023.7  
Impairments related to Illinois segment 130.0 12.1 178.9  
Depreciation and amortization 1,317.6 1,222.3 1,132.1  
Property and revenue taxes 260.4 250.5 233.5  
Equity in earnings of transmission affiliates 0.0 0.0 0.0  
Other income, net 105.5 154.5 144.9  
Interest expense 746.8 748.4 705.8  
Gain on debt extinguishments   0.0 0.0  
Income tax expense (benefit) 293.0 336.8 302.3  
Preferred stock dividends of subsidiary 1.2 1.2 1.2  
Net loss attributed to noncontrolling interests 0.0 0.0 0.0  
Net income (loss) attributed to common shareholders 1,237.7 1,169.7 1,039.4  
Capital expenditures and asset acquisitions 4,278.7 2,808.4 2,727.7  
Equity method investments 17.8 15.7 14.4  
Total assets 43,885.7 40,437.5 38,069.0  
Public utilities | Wisconsin        
Segment information        
Gain on debt extinguishments   0.0    
Public utilities | Wisconsin | Operating segments        
Segment information        
Fuel and purchased power 1,674.9 1,455.7 1,615.9  
Cost of natural gas sold 871.5 661.9 894.7  
Other operation and maintenance 1,737.9 1,547.9 1,531.3  
Impairments related to Illinois segment 0.0 0.0 0.0  
Depreciation and amortization 1,008.1 919.9 851.5  
Property and revenue taxes 178.7 169.6 179.2  
Equity in earnings of transmission affiliates 0.0 0.0 0.0  
Other income, net 96.5 146.6 137.6  
Interest expense 638.7 637.3 601.0  
Gain on debt extinguishments     0.0  
Income tax expense (benefit) 226.2 220.5 237.4  
Preferred stock dividends of subsidiary 1.2 1.2 1.2  
Net loss attributed to noncontrolling interests 0.0 0.0 0.0  
Net income (loss) attributed to common shareholders 1,054.8 863.1 851.3  
Capital expenditures and asset acquisitions 3,860.1 2,347.1 2,134.4  
Equity method investments 17.8 15.7 14.4  
Total assets 33,984.7 30,622.7 28,527.3  
Public utilities | Illinois        
Segment information        
Gain on debt extinguishments   0.0    
Public utilities | Illinois | Operating segments        
Segment information        
Fuel and purchased power 0.0 0.0 0.0  
Cost of natural gas sold 508.0 376.7 443.0  
Other operation and maintenance 482.2 461.5 397.9  
Impairments related to Illinois segment 130.0 12.1 178.9  
Depreciation and amortization 259.7 255.4 237.3  
Property and revenue taxes 55.5 59.9 29.9  
Equity in earnings of transmission affiliates 0.0 0.0 0.0  
Other income, net 8.6 7.6 6.7  
Interest expense 88.9 94.7 88.9  
Gain on debt extinguishments     0.0  
Income tax expense (benefit) 45.8 97.6 48.6  
Preferred stock dividends of subsidiary 0.0 0.0 0.0  
Net loss attributed to noncontrolling interests 0.0 0.0 0.0  
Net income (loss) attributed to common shareholders 122.1 252.1 140.0  
Capital expenditures and asset acquisitions 306.1 343.0 489.8  
Equity method investments 0.0 0.0 0.0  
Total assets 8,167.7 8,168.8 7,970.2  
Public utilities | Other States        
Segment information        
Gain on debt extinguishments   0.0    
Public utilities | Other States | Operating segments        
Segment information        
Fuel and purchased power 0.0 0.0 0.0  
Cost of natural gas sold 246.3 198.6 277.2  
Other operation and maintenance 104.6 93.9 94.5  
Impairments related to Illinois segment 0.0 0.0 0.0  
Depreciation and amortization 49.8 47.0 43.3  
Property and revenue taxes 26.2 21.0 24.4  
Equity in earnings of transmission affiliates 0.0 0.0 0.0  
Other income, net 0.4 0.3 0.6  
Interest expense 19.2 16.4 15.9  
Gain on debt extinguishments     0.0  
Income tax expense (benefit) 21.0 18.7 16.3  
Preferred stock dividends of subsidiary 0.0 0.0 0.0  
Net loss attributed to noncontrolling interests 0.0 0.0 0.0  
Net income (loss) attributed to common shareholders 60.8 54.5 48.1  
Capital expenditures and asset acquisitions 112.5 118.3 103.5  
Equity method investments 0.0 0.0 0.0  
Total assets 1,733.3 1,646.0 1,571.5  
External revenues        
Segment information        
Operating revenues 9,800.1 8,599.9 8,893.0  
External revenues | Reconciling eliminations        
Segment information        
Operating revenues 0.0 0.0 0.0  
External revenues | Electric transmission | Operating segments        
Segment information        
Operating revenues 0.0 0.0 0.0  
External revenues | Non-Utility Energy Infrastructure | Operating segments        
Segment information        
Operating revenues 293.5 217.2 190.1  
External revenues | Corporate and other | Operating segments        
Segment information        
Operating revenues 0.0 0.0 0.1  
External revenues | Public utilities        
Segment information        
Operating revenues 9,506.6 8,382.7 8,702.8  
External revenues | Public utilities | Wisconsin | Operating segments        
Segment information        
Operating revenues 7,295.5 6,330.5 6,625.9  
External revenues | Public utilities | Illinois | Operating segments        
Segment information        
Operating revenues 1,683.6 1,602.4 1,557.8  
External revenues | Public utilities | Other States | Operating segments        
Segment information        
Operating revenues 527.5 449.8 519.1  
Intersegment revenues        
Segment information        
Operating revenues 0.0 0.0 0.0  
Intersegment revenues | Reconciling eliminations        
Segment information        
Operating revenues (476.7) (474.1) (476.4)  
Intersegment revenues | Electric transmission | Operating segments        
Segment information        
Operating revenues 0.0 0.0 0.0  
Intersegment revenues | Non-Utility Energy Infrastructure | Operating segments        
Segment information        
Operating revenues 476.7 474.1 476.4  
Intersegment revenues | Corporate and other | Operating segments        
Segment information        
Operating revenues 0.0 0.0 0.0  
Intersegment revenues | Public utilities        
Segment information        
Operating revenues 0.0 0.0 0.0  
Intersegment revenues | Public utilities | Wisconsin | Operating segments        
Segment information        
Operating revenues 0.0 0.0 0.0  
Intersegment revenues | Public utilities | Illinois | Operating segments        
Segment information        
Operating revenues 0.0 0.0 0.0  
Intersegment revenues | Public utilities | Other States | Operating segments        
Segment information        
Operating revenues $ 0.0 0.0 0.0  
ATC        
Segment information        
Equity method investment, ownership interest (as a percent) 60.00%      
Equity method investments $ 2,256.9 2,085.1 1,980.8 $ 1,884.6
ATC | Electric transmission        
Segment information        
Equity method investment, ownership interest (as a percent) 60.00%      
ATC Holdco        
Segment information        
Equity method investment, ownership interest (as a percent) 75.00%      
Equity method investments $ 23.5 $ 23.8 $ 25.1 $ 24.6
ATC Holdco | Electric transmission        
Segment information        
Equity method investment, ownership interest (as a percent) 75.00%      
v3.25.4
Variable Interest Entities - WEPCo Environmental Trust (Details) - USD ($)
$ in Millions
1 Months Ended
Nov. 30, 2020
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Assets        
Other current assets (restricted cash)   $ 9.1 $ 5.3 $ 70.1
Regulatory assets   3,156.3 3,339.7  
Other long-term assets (restricted cash)   34.2 27.1 $ 52.2
Liabilities        
Current portion of long-term debt   1,519.4 1,729.0  
Accounts payable   1,140.1 1,137.1  
Long-term debt   18,498.1 17,178.1  
WEPCo Environmental Trust Finance I, LLC        
Variable interest entities        
Securitization of environmental control costs related to Pleasant Prairie power plant $ 100.0      
Assets        
Other current assets (restricted cash)   2.0 1.5  
Regulatory assets   67.5 76.5  
Other long-term assets (restricted cash)   0.6 0.6  
Liabilities        
Current portion of long-term debt   9.3 9.2  
Accounts payable   0.1 0.0  
Other current liabilities (accrued interest)   0.1 0.1  
Long-term debt   $ 67.4 $ 76.4  
v3.25.4
Variable Interest Entities - Investment in Transmission Affiliates (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Variable interest entities        
Equity investment $ 2,353.9 $ 2,191.6 $ 2,081.6  
ATC        
Variable interest entities        
Ownership interest (as a percent) 60.00%      
Equity investment $ 2,256.9 2,085.1 1,980.8 $ 1,884.6
ATC Holdco        
Variable interest entities        
Ownership interest (as a percent) 75.00%      
Equity investment $ 23.5 $ 23.8 $ 25.1 $ 24.6
v3.25.4
Commitments and Contingencies - Unconditional Purchase Obligations (Details)
$ in Millions
Dec. 31, 2025
USD ($)
Minimum future commitments for purchase obligations  
Total Amounts Committed $ 9,525.3
2026 1,543.3
2027 1,461.6
2028 1,366.1
2029 1,250.3
2030 1,166.0
Later Years 2,738.0
Nuclear | Electric  
Minimum future commitments for purchase obligations  
Total Amounts Committed 5,045.8
2026 681.6
2027 730.4
2028 782.6
2029 838.5
2030 898.5
Later Years 1,114.2
Coal supply and transportation | Electric  
Minimum future commitments for purchase obligations  
Total Amounts Committed 412.1
2026 242.2
2027 127.7
2028 37.0
2029 3.5
2030 1.7
Later Years 0.0
Purchased power | Electric  
Minimum future commitments for purchase obligations  
Total Amounts Committed 335.3
2026 61.6
2027 56.3
2028 52.4
2029 25.6
2030 5.9
Later Years 133.5
Other | Electric  
Minimum future commitments for purchase obligations  
Total Amounts Committed 85.5
2026 12.0
2027 12.1
2028 9.6
2029 8.4
2030 8.5
Later Years 34.9
Supply and transportation | Natural gas  
Minimum future commitments for purchase obligations  
Total Amounts Committed 2,921.3
2026 487.0
2027 478.8
2028 426.8
2029 323.6
2030 203.0
Later Years 1,002.1
Non-Utility Energy Infrastructure | Purchased power | Electric  
Minimum future commitments for purchase obligations  
Total Amounts Committed 720.7
2026 55.0
2027 56.3
2028 57.6
2029 50.7
2030 48.4
Later Years 452.7
Non-Utility Energy Infrastructure | Natural gas storage and transportation | Natural gas  
Minimum future commitments for purchase obligations  
Total Amounts Committed 4.6
2026 3.9
2027 0.0
2028 0.1
2029 0.0
2030 0.0
Later Years $ 0.6
v3.25.4
Commitments and Contingencies - Environmental Matters (Details)
$ in Millions
1 Months Ended 12 Months Ended
Jun. 30, 2025
MMBTU
May 31, 2024
MMBTU
Feb. 29, 2024
micrograms
Aug. 31, 2018
Dec. 31, 2025
USD ($)
performance_obligations
MW
Dec. 31, 2024
USD ($)
Nov. 30, 2023
Years
Manufactured Gas Plant Remediation              
Regulatory asset         $ 3,173.6 $ 3,378.7  
Estimated future cash expenditures for environmental remediation         484.1 445.8  
Environmental remediation costs              
Manufactured Gas Plant Remediation              
Regulatory asset         566.0 570.1  
Estimated future cash expenditures for environmental remediation         $ 484.1    
Mercury and Air Toxics Standards | Electric              
Air Quality              
Particulate matter in pounds per million british thermal unit prior to the EPA lowering it in May 2024 | MMBTU   0.03          
Lower limit for particulate matter per million british thermal unit after the EPA lowered it | MMBTU   0.01          
Level of particulate matter in pounds per million british thermal unit that the EPA is proposing to return to | MMBTU 0.03            
National Ambient Air Quality Standards | Electric              
Air Quality              
Previous level of micrograms per cubic meter under 24-Hour standard that particulate matter needed to be below | micrograms     12        
National Ambient Air Quality Standards | Electric | Minimum              
Air Quality              
Number of years between evaluation of attainment status       3 years      
National Ambient Air Quality Standards | Electric | Maximum              
Air Quality              
New primary annual PM2.5 level | micrograms     9        
Climate Change | Electric              
Air Quality              
Number of applicable GHG performance standards for coal plants | performance_obligations         0    
Capacity of fossil-fueled generation retired, in megawatts | MW         2,500    
Capacity of coal-fired generation to be retired by the end of 2031, in megawatts | MW         900    
Manufactured Gas Plant Remediation | Natural gas              
Manufactured Gas Plant Remediation              
Estimated future cash expenditures for environmental remediation         $ 484.1 445.8  
Manufactured Gas Plant Remediation | Natural gas | Environmental remediation costs              
Manufactured Gas Plant Remediation              
Regulatory asset         $ 566.0 $ 570.1  
Renewables, Efficiency, and Conservation | Electric | Wisconsin              
Renewables, Efficiency, and Conservation              
Annual state renewable portfolio requirement, as a percent         10.00%    
Percent of annual operating revenues used to fund renewable program         1.20%    
Renewables, Efficiency, and Conservation | Electric | Wisconsin | WE              
Renewables, Efficiency, and Conservation              
Required renewable energy percent achieved         8.27%    
Renewables, Efficiency, and Conservation | Electric | Wisconsin | WPS              
Renewables, Efficiency, and Conservation              
Required renewable energy percent achieved         9.74%    
Renewables, Efficiency, and Conservation | Electric | Michigan              
Renewables, Efficiency, and Conservation              
Annual state renewable portfolio requirement for 2019 and 2020, as a percent         12.50%    
Annual energy optimization target, as a percent         1.00%    
Percentage renewable portfolio requirement 2021 and beyond         15.00%    
Required renewable energy plan filing time period | Years             2
Percentage proposed renewable energy target through 2029             15.00%
Percentage proposed renewable energy target from 2030 through 2034             50.00%
Percentage proposed renewable energy target for 2035 and thereafter             60.00%
Percentage proposed clean energy standards for 2035 through 2039             80.00%
Percentage proposed clean energy standards after 2040             100.00%
Required energy waste reduction plan filing time period until 2025 | Years             2
Required energy waste reduction plan filing time period after 2025 | Years             3
v3.25.4
Supplemental Cash Flow Information - Supplemental Information (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Supplemental cash flow information      
Cash paid for interest, net of amount capitalized $ 858.5 $ 785.7 $ 653.4
Cash received for income taxes, net (281.3) (264.2) (58.9)
Significant non-cash investing and financing transactions      
Accounts payable related to construction costs 232.0 285.7 171.3
Common stock issued for stock-based compensation plans 3.2 6.4 0.0
Increase in receivables related to property damage insurance proceeds 3.5 2.3 3.5
Increase in receivables for corporate-owned life insurance proceeds 0.0 5.8 1.4
Liabilities accrued for software licensing agreement $ 21.1 $ 0.2 $ 0.0
v3.25.4
Supplemental Cash Flow Information - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Supplemental Cash Flow Information [Abstract]        
Cash and cash equivalents $ 27.6 $ 9.8 $ 42.9  
Restricted cash included in other current assets 9.1 5.3 70.1  
Restricted cash included in other long-term assets 34.2 27.1 52.2  
Cash, cash equivalents, and restricted cash $ 70.9 $ 42.2 $ 165.2 $ 182.2
v3.25.4
Regulatory Environment - WI VLC and Bespoke Resources Tariffs (Details) - Public Service Commission of Wisconsin (PSCW) - WE - Very Large Customer and Bespoke Resources Tariffs
1 Months Ended
Mar. 31, 2025
MW
tariff
resource
Public Utilities, General Disclosures  
Minimum Megawatts Required for VLCs | MW 500
Number of New Tariffs Being Proposed | tariff 2
Minimum number of Bespoke Resources | resource 1
Term of service agreements for wind and solar resources 20 years
Requested Equity Capital Structure, Percentage 57.00%
Minimum  
Public Utilities, General Disclosures  
Requested Return on Equity, Percentage 10.48%
Maximum  
Public Utilities, General Disclosures  
Requested Return on Equity, Percentage 10.98%
v3.25.4
Regulatory Environment - WI 2025 and 2026 Rates (Details) - Public Service Commission of Wisconsin (PSCW)
$ in Millions
1 Months Ended
Dec. 31, 2024
USD ($)
WE | 2025 Rates | Electric  
Public Utilities, General Disclosures  
Approved rate increase $ 144.0
Approved rate increase (as a percent) 4.20%
WE | 2025 Rates | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 41.3
Approved rate increase (as a percent) 7.10%
WE | 2025 Rates | Steam  
Public Utilities, General Disclosures  
Approved rate increase $ 1.5
Approved rate increase (as a percent) 5.00%
WE | 2026 Rates | Electric  
Public Utilities, General Disclosures  
Approved rate increase $ 169.5
Approved rate increase (as a percent) 4.50%
WE | 2026 Rates | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 29.8
Approved rate increase (as a percent) 4.50%
WE | 2025 and 2026 Rates  
Public Utilities, General Disclosures  
Approved return on equity (as a percent) 9.80%
Approved common equity component average (as a percent) 53.00%
Percentage of first 15 basis points of additional earnings retained by the utility 100.00%
Return on equity in excess of authorized amount (as a percent) 0.15%
Percentage of additional earnings between 15 and 40 basis points refunded to customers 50.00%
Return on equity in excess of first 15 basis points above authorized amount (as a percent) 0.25%
Percentage of earnings in excess of 40 basis points refunded to customers 100.00%
WPS | 2025 Rates | Electric  
Public Utilities, General Disclosures  
Approved rate increase $ 55.1
Approved rate increase (as a percent) 4.50%
WPS | 2025 Rates | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 14.9
Approved rate increase (as a percent) 3.80%
WPS | 2026 Rates | Electric  
Public Utilities, General Disclosures  
Approved rate increase $ 30.0
Approved rate increase (as a percent) 2.30%
WPS | 2026 Rates | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 13.5
Approved rate increase (as a percent) 3.10%
WPS | 2025 and 2026 Rates  
Public Utilities, General Disclosures  
Approved return on equity (as a percent) 9.80%
Approved common equity component average (as a percent) 53.00%
Percentage of first 15 basis points of additional earnings retained by the utility 100.00%
Return on equity in excess of authorized amount (as a percent) 0.15%
Return on equity in excess of first 15 basis points above authorized amount (as a percent) 0.60%
Percentage of additional earnings between 15 and 75 basis points refunded to customers 50.00%
Percentage of earnings in excess of 75 basis points refunded to customers 100.00%
WG | 2025 Rates | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 34.5
Approved rate increase (as a percent) 4.20%
WG | 2026 Rates | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 23.5
Approved rate increase (as a percent) 2.60%
WG | 2025 and 2026 Rates  
Public Utilities, General Disclosures  
Approved return on equity (as a percent) 9.80%
Approved common equity component average (as a percent) 53.00%
Percentage of first 15 basis points of additional earnings retained by the utility 100.00%
Return on equity in excess of authorized amount (as a percent) 0.15%
Return on equity in excess of first 15 basis points above authorized amount (as a percent) 0.60%
Percentage of additional earnings between 15 and 75 basis points refunded to customers 50.00%
Percentage of earnings in excess of 75 basis points refunded to customers 100.00%
v3.25.4
Regulatory Environment - WI 2024 Limited Rate Case Re-Opener (Details) - Public Service Commission of Wisconsin (PSCW) - 2024 Rate Case Re-Opener
$ in Millions
1 Months Ended
Dec. 31, 2023
USD ($)
WE | Electric  
Public Utilities, General Disclosures  
Approved rate increase $ 82.2
Approved rate increase (as a percent) 2.50%
WE | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 23.9
Approved rate increase (as a percent) 4.50%
WPS | Electric  
Public Utilities, General Disclosures  
Approved rate increase $ (32.7)
Approved rate increase (as a percent) (2.60%)
WG | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 21.6
Approved rate increase (as a percent) 2.80%
v3.25.4
Regulatory Environment - WI 2023 and 2024 Rates (Details) - Public Service Commission of Wisconsin (PSCW) - 2023 and 2024 Rates
1 Months Ended
Dec. 31, 2022
USD ($)
Public Utilities, General Disclosures  
Percentage of first 15 basis points of additional earnings retained by the utility 100.00%
Return on equity in excess of authorized amount (as a percent) 0.15%
Percentage of additional earnings between 15 and 75 basis points refunded to customers 50.00%
Return on equity in excess of first 15 basis points above authorized amount (as a percent) 0.60%
Percentage of earnings in excess of 75 basis points refunded to customers 100.00%
Commitments to contribute to Keep Wisconsin Warm Fund $ 4,000,000.0
WE  
Public Utilities, General Disclosures  
Approved return on equity (as a percent) 9.80%
Approved common equity component average (as a percent) 53.00%
WE | Electric  
Public Utilities, General Disclosures  
Approved rate increase $ 283,500,000
Approved rate increase (as a percent) 9.10%
Decrease in certain customer fixed charges $ 1.00
WE | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 46,100,000
Approved rate increase (as a percent) 9.60%
WE | Steam  
Public Utilities, General Disclosures  
Approved rate increase $ 7,600,000
Approved rate increase (as a percent) 35.30%
WPS  
Public Utilities, General Disclosures  
Approved return on equity (as a percent) 9.80%
Approved common equity component average (as a percent) 53.00%
WPS | Electric  
Public Utilities, General Disclosures  
Approved rate increase $ 120,500,000
Approved rate increase (as a percent) 9.80%
Decrease in certain customer fixed charges $ 3.33
WPS | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 26,400,000
Approved rate increase (as a percent) 7.10%
WG  
Public Utilities, General Disclosures  
Approved return on equity (as a percent) 9.80%
Approved common equity component average (as a percent) 53.00%
WG | Natural gas  
Public Utilities, General Disclosures  
Approved rate increase $ 46,500,000
Approved rate increase (as a percent) 6.40%
v3.25.4
Regulatory Environment - PGL and NSG 2026 Rate Application (Details) - Illinois Commerce Commission (ICC)
$ in Millions
1 Months Ended
Jan. 31, 2026
USD ($)
Feb. 28, 2025
in
PGL | 2026 Rate Application | Subsequent event    
Public Utilities, General Disclosures    
Requested Rate Increase $ 201.3  
Requested Rate Increase, Percentage 20.95%  
2027 capital investments planned under PRP $ 360.0  
Requested Return on Equity, Percentage 10.10%  
Requested Equity Capital Structure, Percentage 54.00%  
PGL | SMP Proceedings    
Public Utilities, General Disclosures    
Minimum diameter of pipe that does not require replacement | in   36
NSG | 2026 Rate Application | Subsequent event    
Public Utilities, General Disclosures    
Requested Rate Increase $ 12.7  
Requested Rate Increase, Percentage 12.20%  
Requested Return on Equity, Percentage 10.10%  
Requested Equity Capital Structure, Percentage 54.00%  
v3.25.4
Regulatory Environment - PGL and NSG 2023 Rate Order (Details)
$ in Millions
1 Months Ended 3 Months Ended 12 Months Ended
May 30, 2024
USD ($)
Nov. 30, 2023
USD ($)
Dec. 31, 2023
USD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Feb. 28, 2025
in
Jun. 30, 2024
USD ($)
Public Utilities, General Disclosures                
Impairments related to Illinois segment       $ 145.9 $ 12.1 $ 178.9    
2023 Rate Order | Illinois Commerce Commission (ICC)                
Public Utilities, General Disclosures                
Impairments related to Illinois segment     $ 178.9          
2023 Rate Order | Illinois Commerce Commission (ICC) | PGL                
Public Utilities, General Disclosures                
Approved rate increase $ 1.6 $ 304.6            
Approved rate increase (as a percent)   43.50%            
Approved return on equity (as a percent)   9.38%            
Approved common equity component average (as a percent)   50.79%            
Disallowed capital costs   $ 236.2            
Additional capital spending approved $ 28.5              
Impairments related to Illinois segment     177.2          
2023 Rate Order | Illinois Commerce Commission (ICC) | NSG                
Public Utilities, General Disclosures                
Approved rate increase   $ 11.0            
Approved rate increase (as a percent)   11.60%            
Approved return on equity (as a percent)   9.38%            
Approved common equity component average (as a percent)   52.58%            
Disallowed capital costs   $ 1.7            
Impairments related to Illinois segment     $ 1.7          
2023 Rate Order | Illinois Appellate Court                
Public Utilities, General Disclosures                
Disallowed capital costs               $ 237.9
2023 Rate Order | Illinois Appellate Court | PGL                
Public Utilities, General Disclosures                
Disallowance of future SMP capital investments               $ 116.0
SMP Proceedings | Illinois Commerce Commission (ICC) | PGL                
Public Utilities, General Disclosures                
Minimum diameter of pipe that does not require replacement | in             36  
v3.25.4
Regulatory Environment - PGL and NSG UEA Rider (Details) - Illinois Commerce Commission (ICC)
$ in Millions
1 Months Ended
May 31, 2023
USD ($)
Dec. 31, 2025
USD ($)
Assurance
2018 Annual Uncollectible Expense Adjustment Rider Reconciliation | PGL    
Public Utilities, General Disclosures    
Refunds required to customers $ 15.4  
Refund period 9 months  
2018 Annual Uncollectible Expense Adjustment Rider Reconciliation | NSG    
Public Utilities, General Disclosures    
Refunds required to customers $ 0.7  
Refund period 9 months  
Uncollectible Expense Adjustment Rider Reconciliation - Open Years    
Public Utilities, General Disclosures    
Amount of assurance that UEA rider costs will be recoverable | Assurance   0
Minimum annual costs included in UEA rider   $ 10.0
Maximum annual costs included in UEA rider   $ 40.0
v3.25.4
Regulatory Environment - PGL QIP Rider (Details) - USD ($)
$ in Millions
1 Months Ended 3 Months Ended 12 Months Ended
Nov. 30, 2023
Dec. 31, 2025
Sep. 30, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Aug. 31, 2024
Public Utilities, General Disclosures              
Pre-tax charge to income       $ (1,673.5) $ (1,746.3) $ (1,536.3)  
Reduction to revenues       (9,800.1) (8,599.9) (8,893.0)  
Impairments related to Illinois segment       130.0 12.1 178.9  
Interest expense       895.1 $ 815.3 $ 727.4  
PGL              
Public Utilities, General Disclosures              
Impairments related to Illinois segment $ 177.2 $ 130.0 $ 12.1        
Illinois Commerce Commission (ICC) | PGL | 2016 Annual QIP Rider Reconciliation              
Public Utilities, General Disclosures              
Disallowed capital costs             $ 14.8
Pre-tax charge to income     25.3        
Reduction to revenues     12.9        
Impairments related to Illinois segment     12.1        
Interest expense     $ 0.3        
Illinois Commerce Commission (ICC) | PGL | Open Rider QIP Reconciliations              
Public Utilities, General Disclosures              
Aggregate capital costs during open reconciliation years   $ 3,000.0   $ 3,000.0      
v3.25.4
Regulatory Environment - PGL and NSG QIP and UEA Proposed Settlement (Details) - USD ($)
$ in Millions
1 Months Ended 3 Months Ended 12 Months Ended
Feb. 01, 2026
Nov. 30, 2023
Dec. 31, 2025
Sep. 30, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Public Utilities, General Disclosures              
Pre-tax charge to income         $ (1,673.5) $ (1,746.3) $ (1,536.3)
Impairments related to Illinois segment         130.0 12.1 178.9
Reduction to revenues         (9,800.1) $ (8,599.9) $ (8,893.0)
PGL              
Public Utilities, General Disclosures              
Impairments related to Illinois segment   $ 177.2 $ 130.0 $ 12.1      
Illinois Commerce Commission (ICC) | QIP and UEA Proposed Settlement              
Public Utilities, General Disclosures              
Pre-tax charge to income     205.0        
Impairments related to Illinois segment     130.0        
Reduction to revenues     75.0        
Total balance sheet impact recorded     255.0   255.0    
Charge to income recorded in prior years     $ 50.0   $ 50.0    
Illinois Commerce Commission (ICC) | UEA Rider Proposed Settlement Terms | Subsequent event              
Public Utilities, General Disclosures              
Refund period 3 years            
Illinois Commerce Commission (ICC) | UEA Rider Proposed Settlement Terms | PGL | Subsequent event              
Public Utilities, General Disclosures              
Refunds required to customers $ 49.0            
Illinois Commerce Commission (ICC) | UEA Rider Proposed Settlement Terms | NSG | Subsequent event              
Public Utilities, General Disclosures              
Refunds required to customers 1.0            
Illinois Commerce Commission (ICC) | QIP Rider Proposed Settlement Terms | PGL | Subsequent event              
Public Utilities, General Disclosures              
Refunds required to customers $ 75.0            
Refund period 3 years            
Qualified infrastructure investment costs to be removed from rate base $ 130.0            
v3.25.4
Regulatory Environment - MERC 2023 Rate Order (Details) - Minnesota Public Utilities Commission (MPUC) - MERC - USD ($)
$ in Millions
1 Months Ended 3 Months Ended
Nov. 30, 2023
Dec. 31, 2022
Jun. 30, 2024
Public Utilities, General Disclosures      
Interim rate increase   $ 37.0  
Approved rate increase $ 28.8    
Approved rate increase (as a percent) 7.10%    
Approved return on equity (as a percent) 9.65%    
Approved common equity component average (as a percent) 53.00%    
Interim rate refunds      
Public Utilities, General Disclosures      
Amortization of regulatory liabilities     $ 8.9
v3.25.4
Regulatory Environment - MGU 2024 Rate Order (Details) - MPSC - MGU - USD ($)
$ in Millions
1 Months Ended
Aug. 30, 2023
Sep. 30, 2024
Public Utilities, General Disclosures    
Approved rate increase $ 9.9 $ 7.0
Approved rate increase (as a percent) 4.70% 3.88%
Approved return on equity (as a percent) 9.80% 9.86%
Approved common equity component average (as a percent) 51.00% 50.00%
v3.25.4
Regulatory Environment - MGU 2023 Rate Order (Details) - MPSC - MGU - USD ($)
$ in Millions
1 Months Ended
Aug. 30, 2023
Sep. 30, 2024
Public Utilities, General Disclosures    
Approved rate increase $ 9.9 $ 7.0
Approved rate increase (as a percent) 4.70% 3.88%
Approved return on equity (as a percent) 9.80% 9.86%
Approved common equity component average (as a percent) 51.00% 50.00%
v3.25.4
Regulatory Environment - UMERC AREP (Details) - MPSC - UMERC - Amended Renewable Energy Plan - Renegade Solar Project
$ in Millions
Dec. 31, 2025
USD ($)
MW
Public Utilities, General Disclosures  
Capacity of generation unit | MW 100
Estimated cost of project | $ $ 226
v3.25.4
Regulatory Environment - UMERC 2024 Rate Order (Details) - MPSC - UMERC - 2024 Rate Order
$ in Millions
1 Months Ended
Oct. 31, 2024
USD ($)
Public Utilities, General Disclosures  
Approved rate increase $ 6.6
Approved rate increase (as a percent) 8.20%
Approved return on equity (as a percent) 9.86%
Approved common equity component average (as a percent) 50.00%
v3.25.4
Other Income, Net (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Other Income and Expenses [Abstract]      
Non-service components of net periodic benefit costs Other income, net Other income, net Other income, net
Other Income, Net [Line Items]      
AFUDC - Equity $ 99.8 $ 59.8 $ 59.1
Gains from investments held in rabbi trust 8.1 11.7 13.7
Interest income 5.9 17.2 3.9
Non-service components of net periodic benefit costs 2.7 83.7 97.7
Other, net 1.8 1.1 4.4
Other income, net 107.9 178.2 177.7
Equity method investments excluding transmission affiliates      
Other Income, Net [Line Items]      
Earnings (losses) from equity method investments $ (10.4) $ 4.7 $ (1.1)
v3.25.4
Schedule I - Income Statements (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income statements      
Other income, net $ 107.9 $ 178.2 $ 177.7
Gain on debt extinguishments 0.0 (23.1) (0.5)
Income before income taxes 1,673.5 1,746.3 1,536.3
Income tax benefit (118.0) (222.0) (204.6)
Net income attributed to common shareholders 1,557.5 1,527.2 1,331.7
WEC Energy Group      
Income statements      
Operating expenses 3.6 5.4 2.5
Equity earnings of subsidiaries 1,819.2 1,724.2 1,502.5
Other income, net 26.5 32.0 19.6
Interest expense 399.3 333.6 260.8
Gain on debt extinguishments 0.0 (23.1) 0.0
Income before income taxes 1,442.8 1,440.3 1,258.8
Income tax benefit 114.7 86.9 72.9
Net income attributed to common shareholders $ 1,557.5 $ 1,527.2 $ 1,331.7
v3.25.4
Schedule I - Statements of Comprehensive Income (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Statements of comprehensive income      
Net income attributed to common shareholders $ 1,557.5 $ 1,527.2 $ 1,331.7
Other comprehensive income (loss), net of tax 0.2 (0.1) (0.9)
Derivatives accounted for as cash flow hedges      
Reclassification of realized derivative gains to net income, net of tax (0.2) (0.3) (0.3)
Defined benefit plans      
Pension and OPEB adjustments arising during the period, net of tax 0.2 0.1 (0.6)
Amortization of pension and OPEB costs included in net periodic benefit cost, net of tax 0.2 0.1 0.0
Defined benefit plans, net 0.4 0.2 (0.6)
WEC Energy Group      
Statements of comprehensive income      
Net income attributed to common shareholders 1,557.5 1,527.2 1,331.7
Other comprehensive income (loss) from subsidiaries, net of tax 0.1 0.1 (0.5)
Other comprehensive income (loss), net of tax 0.2 (0.1) (0.9)
Comprehensive income attributed to common shareholders 1,557.7 1,527.1 1,330.8
WEC Energy Group | Derivatives accounted for as cash flow hedges      
Derivatives accounted for as cash flow hedges      
Reclassification of realized derivative gains to net income, net of tax (0.2) (0.3) (0.3)
WEC Energy Group | Defined benefit plans      
Defined benefit plans      
Pension and OPEB adjustments arising during the period, net of tax 0.2 0.0 (0.2)
Amortization of pension and OPEB costs included in net periodic benefit cost, net of tax 0.1 0.1 0.1
Defined benefit plans, net $ 0.3 $ 0.1 $ (0.1)
v3.25.4
Schedule I - Balance Sheets (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Current assets      
Cash and cash equivalents $ 27.6 $ 9.8 $ 42.9
Prepaid income taxes 178.8 214.9  
Current assets 3,284.7 2,911.7  
Long-term assets      
Equity method investments 2,353.9 2,191.6 2,081.6
Other 383.6 336.2  
Long-term assets 48,233.6 44,451.5  
Total assets 51,518.3 47,363.2 $ 43,939.7
Current liabilities      
Current portion of long-term debt 1,519.4 1,729.0  
Accounts payable 1,140.1 1,137.1  
Other 1,009.2 859.2  
Current liabilities 5,593.4 4,841.9  
Long-term liabilities      
Long-term debt 18,498.1 17,178.1  
Other 963.4 838.1  
Long-term liabilities 31,872.1 29,719.4  
Equity      
Total liabilities and equity 51,518.3 47,363.2  
WEC Energy Group      
Current assets      
Cash and cash equivalents 0.1 0.0  
Prepaid income taxes 14.9 16.3  
Current assets 81.2 82.2  
Long-term assets      
Equity method investments 22,222.1 19,809.0  
Other 56.0 23.2  
Long-term assets 22,738.1 20,132.2  
Total assets 22,819.3 20,214.4  
Current liabilities      
Short-term debt 702.9 382.7  
Current portion of long-term debt 1,350.0 620.0  
Other 69.5 69.4  
Current liabilities 2,905.8 1,656.1  
Long-term liabilities      
Long-term debt 6,280.2 6,135.4  
Other 19.7 28.0  
Long-term liabilities 6,299.9 6,163.4  
Equity      
Common shareholders' equity 13,613.6 12,394.9  
Total liabilities and equity 22,819.3 20,214.4  
WEC Energy Group | Related Party      
Current assets      
Accounts receivable from related parties 3.2 2.7  
Notes receivable from related parties 63.0 63.2  
Long-term assets      
Note receivable from WECI 460.0 300.0  
Current liabilities      
Accounts payable 5.0 3.1  
Notes payable to related parties $ 778.4 $ 580.9  
v3.25.4
Schedule I - Statements of Cash Flows (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Operating activities      
Net income attributed to common shareholders $ 1,557.5 $ 1,527.2 $ 1,331.7
Reconciliation to cash provided by operating activities      
Equity income in subsidiaries, net of distributions (29.2) (57.4) (33.0)
Gain on debt extinguishments 0.0 (23.1) (0.5)
Change in -      
Prepaid income taxes 36.1 (41.0) 27.9
Other current assets 11.4 (34.4) 8.4
Other current liabilities 86.5 13.8 56.5
Other, net 93.2 (56.9) (160.5)
Net cash provided by operating activities 3,379.4 3,211.8 3,018.4
Investing activities      
Capital contributions to subsidiaries (142.4) (45.5) (63.7)
Other, net 32.1 9.7 13.3
Net cash used in investing activities (4,874.7) (3,802.5) (3,558.2)
Financing activities      
Exercise of stock options 39.1 23.7 6.3
Issuance of common stock, net 761.9 163.4 0.0
Purchase of common stock (1.3) (3.2) (16.6)
Dividends paid on common stock (1,147.8) (1,056.2) (984.2)
Issuance of long-term debt 2,844.5 4,460.9 2,170.0
Retirement of long-term debt (1,728.9) (2,138.0) (1,005.4)
Change in commercial paper 806.9 (902.8) 373.7
Payments for debt extinguishment and issuance costs (39.9) (45.9) (14.2)
Other, net (10.5) (6.1) (6.8)
Net cash provided by financing activities 1,524.0 467.7 522.8
Net change in cash, cash equivalents, and restricted cash 28.7 (123.0) (17.0)
Cash, cash equivalents, and restricted cash at beginning of year 42.2 165.2 182.2
Cash, cash equivalents, and restricted cash at end of year 70.9 42.2 165.2
WEC Energy Group      
Operating activities      
Net income attributed to common shareholders 1,557.5 1,527.2 1,331.7
Reconciliation to cash provided by operating activities      
Equity income in subsidiaries, net of distributions (669.2) (931.8) (566.8)
Deferred income taxes, net (21.5) (2.1) (3.8)
Gain on debt extinguishments 0.0 (23.1) 0.0
Change in -      
Accounts receivable from related parties (0.5) 0.0 (2.0)
Prepaid income taxes 1.4 (16.3) 35.4
Other current assets 0.0 0.2 (0.1)
Accounts payable to related parties 1.9 0.2 0.9
Accrued interest 1.3 (3.6) 42.1
Other current liabilities (0.8) (0.6) (0.7)
Other, net 18.4 15.5 14.4
Net cash provided by operating activities 888.5 565.6 851.1
Investing activities      
Capital contributions to subsidiaries (2,277.7) (1,273.9) (1,807.4)
Return of capital from subsidiaries 537.9 846.6 175.2
Short-term notes receivable from related parties, net 0.2 (47.2) 14.9
Issuance of long-term note receivable to WECI (160.0) 0.0 0.0
Other, net (14.7) 0.0 0.0
Net cash used in investing activities (1,914.3) (474.5) (1,617.3)
Financing activities      
Exercise of stock options 39.1 23.7 6.3
Issuance of common stock, net 761.9 163.4 0.0
Purchase of common stock (1.3) (3.2) (16.6)
Dividends paid on common stock (1,147.8) (1,056.2) (984.2)
Issuance of long-term debt 1,500.0 2,475.0 2,050.0
Retirement of long-term debt (620.0) (1,473.7) (700.0)
Change in commercial paper 320.2 (314.3) 297.3
Short-term notes payable to related parties, net 197.5 121.3 127.1
Payments for debt extinguishment and issuance costs (23.7) (27.0) (13.3)
Other, net 0.0 (0.1) (0.4)
Net cash provided by financing activities 1,025.9 (91.1) 766.2
Net change in cash, cash equivalents, and restricted cash 0.1 0.0 0.0
Cash, cash equivalents, and restricted cash at beginning of year 0.0 0.0 0.0
Cash, cash equivalents, and restricted cash at end of year $ 0.1 $ 0.0 $ 0.0
v3.25.4
Schedule I - Cash Dividends Received from Subsidiaries (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
WECI      
Notes to parent company financial statements      
Return of capital from subsidiaries $ 534.5 $ 843.9 $ 171.6
Wispark      
Notes to parent company financial statements      
Return of capital from subsidiaries 2.9 2.7 3.6
WEC Energy Group      
Notes to parent company financial statements      
Cash dividends received from subsidiaries 1,150.0 792.4 935.7
Return of capital from subsidiaries 537.9 846.6 175.2
WEC Energy Group | WE      
Notes to parent company financial statements      
Cash dividends received from subsidiaries 600.0 240.0 370.0
WEC Energy Group | We Power      
Notes to parent company financial statements      
Cash dividends received from subsidiaries 175.6 225.3 192.8
WEC Energy Group | WECI      
Notes to parent company financial statements      
Cash dividends received from subsidiaries 152.5 127.2 93.7
WEC Energy Group | WG      
Notes to parent company financial statements      
Cash dividends received from subsidiaries 100.0 80.0 171.0
WEC Energy Group | ATC Holding LLC      
Notes to parent company financial statements      
Cash dividends received from subsidiaries 73.9 104.6 86.8
WEC Energy Group | UMERC      
Notes to parent company financial statements      
Cash dividends received from subsidiaries 23.0 15.0 21.0
WEC Energy Group | Bluewater      
Notes to parent company financial statements      
Cash dividends received from subsidiaries 20.0 0.0 0.0
WEC Energy Group | WEC Investments, LLC      
Notes to parent company financial statements      
Cash dividends received from subsidiaries 4.3 0.0 0.0
WEC Energy Group | Wispark      
Notes to parent company financial statements      
Cash dividends received from subsidiaries $ 0.7 $ 0.3 $ 0.4
v3.25.4
Schedule I - Long-Term Debt (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Future maturities of long-term debt outstanding    
2026 $ 1,519.4  
2027 2,137.3  
2028 3,203.2  
2029 2,943.4  
2030 1,691.9  
Thereafter 8,644.7  
Long-term debt 18,498.1 $ 17,178.1
WEC Energy Group    
Future maturities of long-term debt outstanding    
2026 1,350.0  
2027 1,762.5  
2028 1,850.0  
2029 862.5  
2030 300.0  
Thereafter 1,550.0  
Total 7,675.0  
Long-term debt 6,280.2 $ 6,135.4
WEC Energy Group | WECC | Support agreement related to WECC debt    
Future maturities of long-term debt outstanding    
Long-term debt $ 50.0  
v3.25.4
Schedule I - Fair Value Measurements (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Carrying amount    
Notes to parent company financial statements    
Long-term debt, including current portion $ 20,017.5 $ 18,907.1
Fair value    
Notes to parent company financial statements    
Long-term debt, including current portion 19,609.1 17,840.8
Long-term debt, including current portion 20,017.5 18,907.1
WEC Energy Group | Carrying amount    
Notes to parent company financial statements    
Long-term debt, including current portion 7,630.2 6,755.4
WEC Energy Group | Carrying amount | WECI    
Notes to parent company financial statements    
Long-term notes receivable from WECI 460.0 300.0
WEC Energy Group | Fair value    
Notes to parent company financial statements    
Long-term debt, including current portion 7,922.9 6,776.0
WEC Energy Group | Fair value | WECI    
Notes to parent company financial statements    
Long-term notes receivable from WECI $ 464.6 $ 300.0
v3.25.4
Schedule 1 - Guarantees (Details)
$ in Millions
Dec. 31, 2025
USD ($)
Notes to parent company financial statements  
Total guarantees $ 244.3
Guarantees expiring in less than one year 77.1
Guarantees expiring within one to three years 30.3
Guarantees with expiration over three years 136.9
Standby letters of credit  
Notes to parent company financial statements  
Total guarantees 188.2
Guarantees expiring in less than one year 30.7
Guarantees expiring within one to three years 30.2
Guarantees with expiration over three years 127.3
Surety bonds  
Notes to parent company financial statements  
Total guarantees 46.5
Guarantees expiring in less than one year 46.4
Guarantees expiring within one to three years 0.1
Guarantees with expiration over three years 0.0
Other guarantees  
Notes to parent company financial statements  
Total guarantees 9.6
Guarantees expiring in less than one year 0.0
Guarantees expiring within one to three years 0.0
Guarantees with expiration over three years 9.6
WEC Energy Group  
Notes to parent company financial statements  
Total guarantees 506.6
Guarantees expiring in less than one year 152.0
Guarantees expiring within one to three years 41.1
Guarantees with expiration over three years 313.5
WEC Energy Group | WECI  
Notes to parent company financial statements  
Total guarantees 233.5
WEC Energy Group | MERC  
Notes to parent company financial statements  
Total guarantees 39.0
WEC Energy Group | MGU  
Notes to parent company financial statements  
Total guarantees 17.0
WEC Energy Group | Bluewater  
Notes to parent company financial statements  
Total guarantees 10.1
WEC Energy Group | NSG  
Notes to parent company financial statements  
Total guarantees 6.0
WEC Energy Group | UMERC  
Notes to parent company financial statements  
Total guarantees 4.0
WEC Energy Group | Guarantees supporting business operations  
Notes to parent company financial statements  
Total guarantees 309.6
Guarantees expiring in less than one year 74.9
Guarantees expiring within one to three years 11.0
Guarantees with expiration over three years 223.7
WEC Energy Group | Standby letters of credit  
Notes to parent company financial statements  
Total guarantees 140.9
Guarantees expiring in less than one year 30.7
Guarantees expiring within one to three years 30.0
Guarantees with expiration over three years 80.2
WEC Energy Group | Surety bonds  
Notes to parent company financial statements  
Total guarantees 46.5
Guarantees expiring in less than one year 46.4
Guarantees expiring within one to three years 0.1
Guarantees with expiration over three years 0.0
WEC Energy Group | Other guarantees  
Notes to parent company financial statements  
Total guarantees 9.6
Guarantees expiring in less than one year 0.0
Guarantees expiring within one to three years 0.0
Guarantees with expiration over three years $ 9.6
v3.25.4
Schedule I - Supplemental Cash Flow Information (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Notes to parent company financial statements      
Cash received for income taxes, net $ (281.3) $ (264.2) $ (58.9)
WEC Energy Group      
Notes to parent company financial statements      
Cash paid for interest 382.8 324.2 209.1
Cash received for income taxes, net (92.9) (66.7) (104.5)
Issuance of long-term note receivable to WECI 160.0 0.0 0.0
WEC Energy Group | WECI      
Notes to parent company financial statements      
Issuance of long-term note receivable to WECI 0.0 300.0 430.0
Repayment of long-term note receivable to WECI $ 0.0 $ 430.0 $ 0.0
v3.25.4
Schedule I - Short-Term Notes Receivable from Related Parties (Details) - WEC Energy Group - Related Party - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Notes to parent company financial statements    
Notes receivable from related parties $ 63.0 $ 63.2
UMERC    
Notes to parent company financial statements    
Notes receivable from related parties 62.9 63.2
Wispark    
Notes to parent company financial statements    
Notes receivable from related parties $ 0.1 $ 0.0
v3.25.4
Schedule I - Short-Term Notes Payable to Related Parties (Details) - WEC Energy Group - Related Party - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Notes to parent company financial statements    
Notes payable to related parties $ 778.4 $ 580.9
Integrys    
Notes to parent company financial statements    
Notes payable to related parties 515.3 327.0
WECC    
Notes to parent company financial statements    
Notes payable to related parties 112.0 111.1
WBS    
Notes to parent company financial statements    
Notes payable to related parties 97.3 90.4
Bluewater    
Notes to parent company financial statements    
Notes payable to related parties $ 53.8 $ 52.4
v3.25.4
Schedule II - Valuation and Qualifying Accounts (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Valuation and qualifying accounts      
Balance at beginning of period $ 162.8 $ 193.5 $ 199.3
Expense 142.8 104.9 72.0
Deferral - reduction (23.8)    
Deferral - addition   35.8 88.3
Net write-offs (133.1) (171.4) (166.1)
Balance at end of period $ 148.7 $ 162.8 $ 193.5