MONTROSE ENVIRONMENTAL GROUP, INC., 10-K filed on 2/26/2026
Annual Report
v3.25.4
Document and Entity Information - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Feb. 20, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2025    
Document Annual Report true    
Document Transition Report false    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Trading Symbol MEG    
Entity Registrant Name Montrose Environmental Group, Inc.    
Entity Central Index Key 0001643615    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Common Stock, Shares Outstanding   35,980,650  
Entity Public Float     $ 772.1
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Interactive Data Current Yes    
Entity Current Reporting Status Yes    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity File Number 001-39394    
Entity Tax Identification Number 46-4195044    
Entity Incorporation State Country Code DE    
Entity Address Address Line1 5120 Northshore Drive    
Entity Address City Or Town North Little Rock    
Entity Address State Or Province AR    
Entity Address Postal Zip Code 72118    
City Area Code 501    
Local Phone Number 900-6400    
Security12b Title Common Stock, par value $0.000004 per share    
Security Exchange Name NYSE    
Auditor Firm ID 34    
Auditor Opinion

Opinion on the Financial Statements

We have audited the accompanying consolidated statements of financial position of Montrose Environmental Group, Inc. and subsidiaries (the "Company") as of December 31, 2025 and 2024, the related consolidated statements of operations and comprehensive loss, convertible and redeemable series A-2 preferred stock and stockholders’ equity, and cash flows, for each of the three years in the period ended December 31, 2025, and the related notes (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 26, 2026, expressed an unqualified opinion on the Company's internal control over financial reporting.

    
Auditor Name Deloitte & Touche LLP    
Auditor Location Costa Mesa, California    
Documents Incorporated by Reference

Portions of the registrant’s Proxy Statement for the 2026 Annual Meeting of Stockholders are incorporated herein by reference in Part III of this Annual Report on Form 10-K to the extent stated herein. Such proxy statement will be filed with the Securities and Exchange Commission within 120 days of the registrant’s fiscal year ended December 31, 2025.

    
v3.25.4
CONSOLIDATED STATEMENTS OF FINANCIAL POSITION - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Current assets    
Cash, cash equivalents and restricted cash $ 11,223 $ 12,935
Accounts receivable, net 155,380 158,883
Contract assets 58,831 52,091
Prepaid and other current assets 14,959 14,090
Total current assets 240,393 237,999
Non-current assets    
Property and equipment, net 63,853 63,776
Operating lease right-of-use asset, net 36,560 39,755
Finance lease right-of-use asset, net 37,595 19,643
Goodwill 466,786 467,789
Other intangible assets, net 126,383 152,756
Other assets 9,726 8,635
Total assets 981,296 990,353
Current liabilities    
Accounts payable and other accrued liabilities 71,778 63,704
Accrued payroll and benefits 52,773 34,248
Business acquisitions contingent consideration, current 14,883 26,872
Current portion of operating lease liabilities 10,735 11,345
Current portion of finance lease liabilities 6,602 4,627
Current portion of long-term debt 11,230 17,866
Total current liabilities 168,001 158,662
Non-current liabilities    
Business acquisitions contingent consideration, long-term 2,755 6,255
Other non-current liabilities 7,088 5,550
Deferred tax liabilities, net 21,817 13,312
Operating lease liability, net of current portion 28,215 30,880
Finance lease liability, net of current portion 25,180 11,460
Long-term debt, net of deferred financing fees 277,065 204,818
Total liabilities 530,121 451,161
Commitments and contingencies
Stockholders' equity:    
Additional paid-in-capital 727,927 721,067
Accumulated deficit (273,513) (272,670)
Accumulated other comprehensive loss (3,239) (2,133)
Total stockholders’ equity 451,175 446,264
Total liabilities, convertible and redeemable Series A-2 Preferred Stock and Stockholders' Equity 981,296 990,353
Conversion Option Related to Series A-2 Preferred Stock    
Non-current liabilities    
Conversion option related to Series A-2 Preferred Stock 0 20,224
Convertible And Redeemable Series A-2 Preferred Stock    
Non-current liabilities    
Redeemable series preferred stock $ 0 $ 92,928
v3.25.4
CONSOLIDATED STATEMENTS OF FINANCIAL POSITION (Parenthetical) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Common stock, par value $ 0.000004 $ 0.000004
Common stock, shares authorized 190,000,000 190,000,000
Common stock, shares issued 35,929,665 34,309,788
Common stock, shares outstanding 35,929,665 34,309,788
Convertible And Redeemable Series A-2 Preferred Stock    
Temporary equity, par value $ 0.0001 $ 0.0001
Temporary equity, shares authorized 0 11,667
Temporary equity, shares issued 0 11,667
Number of shares outstanding 0 11,667
Temporary equity, aggregate liquidation preference $ 0.0 $ 122.2
v3.25.4
CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($)
shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income Statement [Abstract]      
Revenues $ 830,538 $ 696,395 $ 624,208
Cost of revenues (exclusive of depreciation and amortization shown below) 496,192 418,193 383,903
Selling, general and administrative expense 270,806 261,627 222,861
Fair value changes in business acquisition contingencies 900 534 84
Depreciation and amortization 50,915 52,762 45,780
Income (loss) from operations 11,725 (36,721) (28,420)
Other income (expense), net 19,063 (1,735) 4,374
Interest expense, net (19,567) (15,862) (7,793)
Total other expense, net (504) (17,597) (3,419)
Income (loss) before expense from income taxes 11,221 (54,318) (31,839)
Income tax expense (benefit) 12,064 7,996 (980)
Net loss (843) (62,314) (30,859)
Equity adjustment from foreign currency translation (1,106) (1,910) (231)
Comprehensive income (loss) $ (1,949) $ (64,224) $ (31,090)
Weighted average common shares outstanding - basic 35,120 33,061 30,058
Weighted average common shares outstanding - diluted 35,120 33,061 30,058
Net income (loss) per share attributable to common stockholders - basic $ (0.14) $ (2.22) $ (1.57)
Net income (loss) per share attributable to common stockholders - diluted $ (0.14) $ (2.22) $ (1.57)
Net income (loss) attributable to common stockholders      
Net (loss) $ (843) $ (62,314) $ (30,859)
Convertible and redeemable Series A-2 Preferred Stock dividend (4,150) (11,064) (16,400)
Net income (loss) attributable to common stockholders $ (4,993) $ (73,378) $ (47,259)
v3.25.4
CONSOLIDATED STATEMENTS OF CONVERTIBLE AND REDEEMABLE SERIES A-2 PREFERRED STOCK AND STOCKHOLDERS' EQUITY - USD ($)
$ in Thousands
Total
Convertible And Redeemable Series A-2 Preferred Stock
Common Stock
Additional Paid-In Capital
Accumulated Deficit
Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2022   $ 152,928        
Beginning balance, shares at Dec. 31, 2022   17,500        
Beginning balance at Dec. 31, 2022 $ 313,187     $ 492,676 $ (179,497) $ 8
Beginning balance, shares at Dec. 31, 2022     29,746,793      
Net Income (Loss) (30,859)       (30,859)  
Stock-based compensation 47,267     47,267    
Dividend payment to the Series A-2 Preferred stockholders (16,400)     (16,400)    
Common stock issuances pursuant to exercises and vesting of equity awards 4,690     4,690    
Common stock issuances pursuant to exercises and vesting of equity awards, shares     330,173      
Acquisitions consideration paid in common stock 2,598     2,598    
Acquisitions consideration paid in common stock, Shares     86,577      
Acquisitions contingent consideration paid in common stock 1,000     1,000    
Acquisitions contingent consideration paid in common stock, Shares     26,688      
Accumulated other comprehensive (loss) (231)         (231)
Ending balance at Dec. 31, 2023   $ 152,928        
Ending balance, shares at Dec. 31, 2023   17,500        
Ending balance at Dec. 31, 2023 321,252     531,831 (210,356) (223)
Ending balance, shares at Dec. 31, 2023     30,190,231      
Net Income (Loss) (62,314)       (62,314)  
Stock-based compensation 64,665     64,665    
Redemption of Series A-2 Preferred Stock   $ (60,000)        
Redemption of Series A-2 Preferred stock, shares   (5,833)        
Dividend payment to the Series A-2 Preferred stockholders (11,064)     (11,064)    
Common stock issuances pursuant to exercises and vesting of equity awards 2,060     2,060    
Common stock issuances pursuant to exercises and vesting of equity awards, shares     320,903      
Issuance of common stock pursuant to follow-on offering 121,776     121,776    
Issuance of common stock pursuant to follow-on offering, shares     3,450,000      
Acquisitions consideration paid in common stock 10,712     10,712    
Acquisitions consideration paid in common stock, Shares     313,394      
Acquisitions contingent consideration paid in common stock 1,087     1,087    
Acquisitions contingent consideration paid in common stock, Shares     35,250      
Accumulated other comprehensive (loss) (1,910)         (1,910)
Ending balance at Dec. 31, 2024   $ 92,928        
Ending balance, shares at Dec. 31, 2024   11,667        
Ending balance at Dec. 31, 2024 446,264     721,067 (272,670) (2,133)
Ending balance, shares at Dec. 31, 2024     34,309,778      
Net Income (Loss) (843)       (843)  
Stock-based compensation 42,716     42,716    
Redemption of Series A-2 Preferred Stock (27,971) $ (94,264)   (27,971)    
Redemption of Series A-2 Preferred stock, shares   (11,667)        
Adjustment of preferred stock issuance costs (1,336) $ 1,336   (1,336)    
Dividend payment to the Series A-2 Preferred stockholders (4,150)     (4,150)    
Common stock issuances pursuant to exercises and vesting of equity awards 1,067     1,067    
Common stock issuances pursuant to exercises and vesting of equity awards, shares     1,659,964      
Common stock withheld related to net share settlement of equity awards (10,738)     (10,738)    
Common stock withheld related to net share settlement of equity awards, Shares     (406,655)      
Acquisitions consideration paid in common stock 7,272     7,272    
Acquisitions consideration paid in common stock, Shares     366,578      
Accumulated other comprehensive (loss) (1,106)         (1,106)
Ending balance at Dec. 31, 2025   $ 0        
Ending balance, shares at Dec. 31, 2025   0        
Ending balance at Dec. 31, 2025 $ 451,175     $ 727,927 $ (273,513) $ (3,239)
Ending balance, shares at Dec. 31, 2025     35,929,665      
v3.25.4
CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Operating activities:      
Net loss $ (843) $ (62,314) $ (30,859)
Adjustments to reconcile net loss to net cash provided by operating activities:      
Provision (recovery) for credit loss 6,713 (146) 3,142
Depreciation and amortization 50,915 52,762 45,780
Non-cash leases expense 11,771 11,572 10,194
Stock-based compensation expense 42,716 64,665 47,267
Fair value changes in financial instruments (18,251) 3,123 (4,129)
Write off of deferred financing costs 913    
Deferred income taxes 9,901 4,286 (980)
Other operating activities, net 668 754  
Changes in operating assets and liabilities, net of acquisitions:      
Accounts receivable and contract assets (10,072) (41,977) (2,923)
Prepaid expenses and other current assets (3,300) (930) (918)
Accounts payable and other accrued liabilities 8,348 3,798 (8,912)
Accrued payroll and benefits 18,525 (1,709) 9,464
Payment of contingent consideration     (611)
Change in operating leases (11,809) (12,027) (10,493)
Other assets 1,281 378  
Net cash provided by operating activities 107,476 22,235 56,022
Investing activities:      
Purchases of property and equipment (16,317) (21,333) (29,578)
Proceeds from the sale of property and equipment 712 2,372 1,544
Proprietary software development and other software costs (695) (2,501) (3,352)
Purchase price true ups 458 (3,287) (1,425)
Minority investments   (210) (2,626)
Cash paid for acquisitions, net of cash acquired   (113,086) (66,187)
Net cash used in investing activities (15,842) (138,045) (101,624)
Financing activities:      
Proceeds from revolving line of credit 477,599 403,116  
Repayment of the revolving line of credit (419,757) (377,615)  
Proceeds from the aircraft loan     10,935
Repayment of aircraft loan (1,146) (1,071) (591)
Proceeds from term loan 200,000 50,000  
Repayment of term loan (191,718) (15,000) (12,211)
Payment of contingent consideration and other purchase price true ups (11,045) (363) (1,949)
Repayment of finance leases (11,092) (5,489) (4,584)
Payments of deferred financing costs (2,407) (348)  
Proceeds from issuance of common stock for exercised stock options 1,067 2,060 4,690
Proceeds from issuance of common stock in follow-on offering, net of issuance costs   121,776  
Taxes paid related to net share settlement of equity awards (10,738)    
Proceeds from building sale leaseback 2,500    
Dividend payment to the series A-2 stockholders (4,150) (11,064) (16,400)
Redemption of series A-2 Preferred Stock (122,235) (60,000)  
Net cash provided by (used in) financing activities (93,122) 106,002 (20,110)
Change in cash, cash equivalents and restricted cash (1,488) (9,808) (65,712)
Foreign exchange impact on cash balance (224) (497) (876)
Cash, cash equivalents and restricted cash:      
Beginning of year 12,935 23,240 89,828
End of year 11,223 12,935 23,240
Supplemental disclosures of cash flows information:      
Cash paid for interest 17,882 14,780 8,059
Cash paid for income tax 5,505 4,194 997
Supplemental disclosures of non-cash investing and financing activities:      
Property and equipment purchased under finance leases 23,384 9,435 8,298
Acquisitions unpaid contingent consideration 17,638 33,127 6,040
Acquisitions contingent consideration paid in common stock 7,272 1,087 1,000
Non-cash considerations received from sale of subsidiary 4,470    
Accrued purchases of property and equipment $ 1,184 983 1,098
Common stock issued to acquire new businesses   $ 10,712 2,598
Accrued lease surrender liability     5,947
Promissory note receivable issued in connection with the sale of assets of the Discontinued Specialty Lab     $ 4,348
v3.25.4
Pay vs Performance Disclosure - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Pay vs Performance Disclosure      
Net Income (Loss) $ (843) $ (62,314) $ (30,859)
v3.25.4
Insider Trading Arrangements
 3 Months Ended
Dec. 31, 2025
shares
Trading Arrangements, by Individual  
Material Terms of Trading Arrangement

On November 11, 2025, Allan Dicks, Chief Financial Officer, amended an existing trading plan intended to satisfy Rule 10b5-1(c). The amended plan provides for the sale of up to 89,142 shares of Company common stock, up to 62,500 of which shares are to be acquired pursuant to the exercise of stock options, between February 10, 2026 and May 12, 2026, subject to certain conditions.

On November 11, 2025, Vijay Manthripragada, Chief Executive Officer, terminated a trading plan intended to satisfy Rule 10b5-1(c). The material terms of the terminated plan were summarized in Part II, Item 5 of the Company’s Quarterly Report on Form 10-Q filed with the SEC on November 5, 2025 and are incorporated herein by reference.

On December 11, 2025, Vijay Manthripragada, Chief Executive Officer, adopted a trading plan intended to satisfy Rule 10b5-1(c). The plan provides for the exercise of up to 119,158 options to purchase shares of Company common stock and the sale of a certain number of shares acquired pursuant to the exercise of such stock options to fulfill the exercise price of 85,992 of such stock options on March 13, 2026, subject to certain conditions.
Allan Dicks [Member]  
Trading Arrangements, by Individual  
Name Allan Dicks
Title Chief Financial Officer
Expiration Date May 12, 2026
Aggregate Available 89,142
Vijay Manthripragada [Member]  
Trading Arrangements, by Individual  
Name Vijay Manthripragada
Title Chief Executive Officer
Rule 10b5-1 Arrangement Adopted true
Adoption Date December 11, 2025
Rule 10b5-1 Arrangement Terminated true
Termination Date November 11, 2025
Expiration Date March 13, 2026
Aggregate Available 119,158
Rule 10b5-1 Trading Plan Sale of Common Stock with Exercise of Stock Options on February 23, 2024 and December 2, 2024 | Allan Dicks [Member]  
Trading Arrangements, by Individual  
Arrangement Duration 91 days
Aggregate Available 62,500
Rule 10b5-1 Trading Plan Sale of Common Stock with Exercise of Stock Options on February 23, 2024 and December 2, 2024 | Vijay Manthripragada [Member]  
Trading Arrangements, by Individual  
Aggregate Available 85,992
v3.25.4
Insider Trading Policies and Procedures
 12 Months Ended
Dec. 31, 2025
Insider Trading Policies and Procedures [Line Items]  
Insider Trading Policies and Procedures Adopted true
v3.25.4
Cybersecurity Risk Management, Strategy, and Governance
 12 Months Ended
Dec. 31, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]  
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]

Risk Management and Strategy

We maintain a cybersecurity risk management program designed to assess, identify, and manage material risks from cybersecurity threats, including unauthorized access to our information systems and the confidential, proprietary, business, and personal information we process and store. Our cybersecurity risk management processes are integrated into our enterprise risk management framework and are aligned with the National Institute for Standards and Technology Risk Management Framework (NIST RMF), other industry-recognized standards, and contractual requirements. These processes are led under the oversight of our Chief Information Officer (CIO) and implemented by a dedicated information security team in coordination with senior management and other business functions.

As part of our cybersecurity risk management processes, we periodically conduct ongoing risk assessments, vulnerability management activities, application security assessments, penetration testing, and security audits to identify and manage cybersecurity risks. We also maintain an enterprise-wide cybersecurity training and awareness program for employees.

We engage third parties in connection with our cybersecurity risk management processes, including a managed security service provider that supports security monitoring and incident response in coordination with our internal team. We also engage assessors, consultants, and auditors from time to time to assist with cybersecurity risk assessment, threat identification, and remediation, and we participate in government and industry information-sharing initiatives.

We have processes to oversee and manage cybersecurity risks associated with third-party service providers, including through monitoring activities and the use of security controls and technologies.

We maintain an incident response plan aligned with NIST RMF that provides for the investigation, containment, escalation, and remediation of cybersecurity incidents, including procedures to assess materiality and escalate potentially material incidents to senior management and the Audit Committee.

As of December 31, 2025, we were not aware of any risks from cybersecurity threats, including as a result of any previous cybersecurity incidents, that have materially affected or are reasonably likely to materially affect us, including our business strategy, results of operations or financial condition.

Governance

In December 2025, Montrose welcomed a new Chief Information Officer (CIO). Our CIO brings deep expertise in cybersecurity and data privacy, supported by more than 20 years of experience leading technology, security, and digital transformation functions across multiple organizations. His background includes overseeing enterprise security programs, implementing large‑scale infrastructure modernization initiatives, and driving the adoption of industry‑standard cybersecurity frameworks designed to enhance organizational resilience.

Montrose has a dedicated cybersecurity team under the oversight of our CIO that is responsible for defining and overseeing the implementation of Montrose’s cybersecurity and data privacy strategies, policies, and procedures. Additionally, a third-party cybersecurity advisor meets with the CIO and cybersecurity team leaders to review strategies and progress. Montrose’s Enterprise Cybersecurity Council, consisting of the CIO, Information Security Director, Infrastructure Director, and senior security architects and engineers, is responsible for identifying, assessing, and managing material risks from cybersecurity threats. The council meets monthly to review cybersecurity risks, evaluate performance metrics, and identify areas for improvement. The council monitors progress on cybersecurity-related projects, employee training completion, and phishing response rates. Additionally, the council monitors the prevention, detection, mitigation, and remediation of cybersecurity incidents. Members possess extensive cybersecurity experience and hold certifications such as Certified Information Security Manager (CISM), Certified Information Systems Security Professional, Certified Ethical Hacker, and Cisco Certified Network Associate.

The Board oversees Montrose’s processes for assessing and mitigating risk, including cybersecurity risk. The Audit Committee maintains delegated oversight of cybersecurity risks, engaging third-party expertise as it determines is needed to advise on infrastructure, policies, and practices. Our CIO briefs the Audit Committee quarterly on cybersecurity and data privacy risks, incidents, and ongoing projects. The full Board receives quarterly updates from the Audit Committee and periodic briefings from the CIO on cybersecurity and data privacy risk management.

In accordance with our Incident Response Plan, in the event of a potentially material cybersecurity event, the Audit Committee as well as our General Council, Chief Financial Officer, and CEO would be notified, briefed, and involved in oversight of mitigation, reporting, and recovery measures as appropriate.
Cybersecurity Risk Management Processes Integrated [Flag] true
Cybersecurity Risk Management Processes Integrated [Text Block] Our cybersecurity risk management processes are integrated into our enterprise risk management framework and are aligned with the National Institute for Standards and Technology Risk Management Framework (NIST RMF), other industry-recognized standards, and contractual requirements.
Cybersecurity Risk Management Third Party Engaged [Flag] true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag] true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag] false
Cybersecurity Risk Board of Directors Oversight [Text Block]

Governance

In December 2025, Montrose welcomed a new Chief Information Officer (CIO). Our CIO brings deep expertise in cybersecurity and data privacy, supported by more than 20 years of experience leading technology, security, and digital transformation functions across multiple organizations. His background includes overseeing enterprise security programs, implementing large‑scale infrastructure modernization initiatives, and driving the adoption of industry‑standard cybersecurity frameworks designed to enhance organizational resilience.

Montrose has a dedicated cybersecurity team under the oversight of our CIO that is responsible for defining and overseeing the implementation of Montrose’s cybersecurity and data privacy strategies, policies, and procedures. Additionally, a third-party cybersecurity advisor meets with the CIO and cybersecurity team leaders to review strategies and progress. Montrose’s Enterprise Cybersecurity Council, consisting of the CIO, Information Security Director, Infrastructure Director, and senior security architects and engineers, is responsible for identifying, assessing, and managing material risks from cybersecurity threats. The council meets monthly to review cybersecurity risks, evaluate performance metrics, and identify areas for improvement. The council monitors progress on cybersecurity-related projects, employee training completion, and phishing response rates. Additionally, the council monitors the prevention, detection, mitigation, and remediation of cybersecurity incidents. Members possess extensive cybersecurity experience and hold certifications such as Certified Information Security Manager (CISM), Certified Information Systems Security Professional, Certified Ethical Hacker, and Cisco Certified Network Associate.

The Board oversees Montrose’s processes for assessing and mitigating risk, including cybersecurity risk. The Audit Committee maintains delegated oversight of cybersecurity risks, engaging third-party expertise as it determines is needed to advise on infrastructure, policies, and practices. Our CIO briefs the Audit Committee quarterly on cybersecurity and data privacy risks, incidents, and ongoing projects. The full Board receives quarterly updates from the Audit Committee and periodic briefings from the CIO on cybersecurity and data privacy risk management.

In accordance with our Incident Response Plan, in the event of a potentially material cybersecurity event, the Audit Committee as well as our General Council, Chief Financial Officer, and CEO would be notified, briefed, and involved in oversight of mitigation, reporting, and recovery measures as appropriate.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block] The Audit Committee maintains delegated oversight of cybersecurity risks, engaging third-party expertise as it determines is needed to advise on infrastructure, policies, and practices.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block] Our CIO briefs the Audit Committee quarterly on cybersecurity and data privacy risks, incidents, and ongoing projects. The full Board receives quarterly updates from the Audit Committee and periodic briefings from the CIO on cybersecurity and data privacy risk management.

In accordance with our Incident Response Plan, in the event of a potentially material cybersecurity event, the Audit Committee as well as our General Council, Chief Financial Officer, and CEO would be notified, briefed, and involved in oversight of mitigation, reporting, and recovery measures as appropriate.
Cybersecurity Risk Role of Management [Text Block]

Montrose has a dedicated cybersecurity team under the oversight of our CIO that is responsible for defining and overseeing the implementation of Montrose’s cybersecurity and data privacy strategies, policies, and procedures. Additionally, a third-party cybersecurity advisor meets with the CIO and cybersecurity team leaders to review strategies and progress. Montrose’s Enterprise Cybersecurity Council, consisting of the CIO, Information Security Director, Infrastructure Director, and senior security architects and engineers, is responsible for identifying, assessing, and managing material risks from cybersecurity threats. The council meets monthly to review cybersecurity risks, evaluate performance metrics, and identify areas for improvement. The council monitors progress on cybersecurity-related projects, employee training completion, and phishing response rates. Additionally, the council monitors the prevention, detection, mitigation, and remediation of cybersecurity incidents. Members possess extensive cybersecurity experience and hold certifications such as Certified Information Security Manager (CISM), Certified Information Systems Security Professional, Certified Ethical Hacker, and Cisco Certified Network Associate.

Cybersecurity Risk Management Positions or Committees Responsible [Flag] true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block] Montrose has a dedicated cybersecurity team under the oversight of our CIO that is responsible for defining and overseeing the implementation of Montrose’s cybersecurity and data privacy strategies, policies, and procedures. Additionally, a third-party cybersecurity advisor meets with the CIO and cybersecurity team leaders to review strategies and progress. Montrose’s Enterprise Cybersecurity Council, consisting of the CIO, Information Security Director, Infrastructure Director, and senior security architects and engineers, is responsible for identifying, assessing, and managing material risks from cybersecurity threats. The council meets monthly to review cybersecurity risks, evaluate performance metrics, and identify areas for improvement.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]

In December 2025, Montrose welcomed a new Chief Information Officer (CIO). Our CIO brings deep expertise in cybersecurity and data privacy, supported by more than 20 years of experience leading technology, security, and digital transformation functions across multiple organizations. His background includes overseeing enterprise security programs, implementing large‑scale infrastructure modernization initiatives, and driving the adoption of industry‑standard cybersecurity frameworks designed to enhance organizational resilience.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block] The council meets monthly to review cybersecurity risks, evaluate performance metrics, and identify areas for improvement. The council monitors progress on cybersecurity-related projects, employee training completion, and phishing response rates. Additionally, the council monitors the prevention, detection, mitigation, and remediation of cybersecurity incidents.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag] true
v3.25.4
Description of the Business and Basis of Presentation
 12 Months Ended
Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Description of the Business and Basis of Presentation

1. DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION

Description of the Business—Montrose Environmental Group, Inc. ("Montrose" or the "Company") is a corporation formed on November 2013, under the laws of the State of Delaware. The Company has approximately 120 offices across the United States, Canada, and Australia and approximately 3,500 employees as of December 31, 2025.

Montrose is an environmental services company serving the recurring environmental needs of a diverse client base, including Fortune 500 companies and federal, state and local governments through the following three segments:

Assessment, Permitting and Response segment provides scientific advisory and consulting services to support environmental assessments, environmental emergency response and recovery, toxicology consulting and environmental audits and permits for current operations, facility upgrades, new projects, decommissioning projects and development projects. The Company works closely with clients to navigate the regulatory process at the local, state, provincial and federal levels, to identify the potential environmental and political impacts of their decisions and develop practical mitigation approaches, as needed. In addition to environmental toxicology and given the Company's expertise in helping businesses plan for and respond to disruptions, the Company's scientists and response teams have helped clients navigate their preparation for and response to emergency response situations.

Measurement and Analysis segment is one of the largest providers of environmental testing and laboratory services in North America. The Company's highly credentialed teams test and analyze air, water and soil to determine concentrations of contaminants, as well as the toxicological impact of contaminants on flora, fauna and human health. The Company's offerings include source and ambient air testing and monitoring, leak detection, and advanced multi-media laboratory services, including air, soil, stormwater, wastewater and drinking water analysis.

Remediation and Reuse segment provides clients with engineering, design, and implementation services, primarily to treat contaminated water and remove contaminants from soil. The Company's team, including engineers, scientists and consultants, provides these services to assist clients in designing solutions, managing products and mitigating environmental risks and liabilities at their locations. The Company does not own the properties or facilities at which it implements these projects or the underlying liabilities, nor does the Company own material amounts of the equipment used in projects.

Basis of Presentation—The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP). Intercompany balances and transactions are eliminated.

Reclassifications—Certain prior year amounts, which are not material, have been reclassified to conform to current year presentation in the consolidated statements of cash flows and notes to the consolidated financial statements.
v3.25.4
Significant Accounting Policies
 12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Significant Accounting Policies

2. SIGNIFICANT ACCOUNTING POLICIES

Use of Estimates—The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates inherent in the preparation of the accompanying consolidated financial statements include, but are not limited to, management’s forecasts of future cash flows used as a basis to assess recoverability of goodwill and long-lived assets, the allocation of purchase price to tangible and intangible assets, allowances for doubtful accounts, the estimated useful lives over which property and equipment is depreciated and intangible assets are amortized, subsequent measurement of goodwill, the fair value of contingent consideration payables, the fair value of embedded derivatives, equity-based compensation expense and deferred taxes. These estimates could materially differ from actual results.

Cash, Cash Equivalents and Restricted Cash—The Company maintains its cash in bank deposit accounts, which at times may exceed federally insured limits. The Company considers cash deposits in banks as cash with original maturities at purchase of three months or less as cash equivalents.

Cash, long-term debt and financial instruments subject the Company to concentrations of credit risk. To minimize the risk of credit loss, these financial instruments are primarily held with large, reputable financial institutions. The Company has not experienced losses in such accounts and believes it is not exposed to any significant credit risk associated with these accounts.

Cash that is restricted as to withdrawal or use under the terms of certain contractual agreements is recorded in restricted cash in the Company’s consolidated statements of financial position. The Company's restricted cash balances were $0.2 million and $1.5 million as of December 31, 2025 and 2024, respectively.

Accounts Receivables-Net—Accounts receivable are presented in the consolidated statements of financial position, net of an allowance for doubtful accounts. The allowance for doubtful accounts is established at the origination of an account in accordance with Accounting Standard Update (ASU) 2016-13, Financial Instruments—Credit Losses (Topic 326). Accounting Standards Codification (ASC) 326 requires the Company to estimate the lifetime expected credit losses on such instruments and to record an allowance to offset the receivables.

Financial Instruments—The Financial Accounting Standards Board (FASB) ASC 820, Fair Value Measurements and Disclosures, defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. ASC 820 establishes a three-level fair value hierarchy that prioritizes the inputs and minimizes the use of unobservable inputs. The three levels of inputs used to measure fair values are as follows:

Level 1—Quoted prices in active markets for identical assets or liabilities.

Level 2—Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data.

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. The inputs to the determination of fair value are based upon the best information in the circumstances and may require significant management judgment or estimation.

The Company considers the carrying values of cash, cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued expenses to approximate fair value for these financial instruments due to the short maturities of these instruments. The Company’s interest rate swap, embedded derivatives, and any acquisition’s contingent consideration are carried at fair value and determined according to the fair value hierarchy above.

The Company’s variable rate borrowings under its Credit Facility (Note 13) is tied to market indices and, thus, approximate fair value. The estimated fair value of the long-term debt under the credit facility is based on borrowing rates currently available to the Company for loans with similar terms and remaining maturities.

Impairment of Long-Lived Assets—Certain events or changes in circumstances may indicate that the recoverability of the carrying amount of long lived assets should be assessed. When such events or changes in circumstances are present, the Company estimates the future cash flows expected to result from the use of the asset (or asset group) and its eventual disposition. If the sum of the expected undiscounted future cash flows is less than the carrying amount, the Company recognizes an impairment based on the fair value of such assets.

Acquisitions—The Company first assesses whether the acquisition represents a purchase of assets or a business. If the transaction is a business acquisition, the Company accounts for the acquisition using business combination accounting, which requires that assets acquired and liabilities assumed be recognized at fair value as of the acquisition date. The purchase price of acquisitions is allocated to the tangible and identifiable intangible assets acquired and liabilities assumed based on estimated fair values, and any excess purchase price over the identifiable assets acquired and liabilities assumed is recorded as goodwill. Goodwill represents the premium the Company pays over the fair value of the net tangible and intangible assets acquired. The Company may use independent valuation specialists to assist in determining the estimated fair values of assets acquired and liabilities assumed, which could require certain significant management assumptions and estimates. Transaction costs associated with acquisitions of businesses are expensed as they are incurred.

Business Acquisition Contingencies—Some of the Company’s acquisition agreements include contingent consideration arrangements, which are generally based on the achievement of future performance thresholds. For each transaction, the Company estimates the fair value of contingent consideration payments as part of the initial purchase price and record the estimated fair value of contingent consideration as a liability. Subsequent changes in the fair value of contingent consideration are recognized as a gain or loss in the consolidated statements of operations. Payments of contingent consideration are reflected in financing activities in the consolidated statements of cash flows to the extent included as part of the initial purchase price, or in operating activities if the payment exceeds the amount included in the initial purchase price.

Goodwill—Goodwill is not amortized but instead qualitatively or quantitatively tested for impairment at least annually. Should an event or circumstances indicate that a reduction in fair value of the reporting unit may have occurred during the year, goodwill would also be tested at such occasion. The Company performs its goodwill test at the reporting unit level. If necessary, the goodwill quantitative impairment test is performed on October 1st every year.

The Company uses a two-step process to assess the realizability of goodwill. The first step (generally referred to as a "step 0" analysis) is a qualitative assessment that analyzes current economic indicators associated with a particular reporting unit. For example, the Company analyzes changes in economic, market and industry conditions, business strategy, cost factors, and financial performance, among others, to determine if there are indicators of a significant decline in the fair value of a particular reporting unit. If the qualitative assessment indicates a stable or improved fair value, no further testing is required. If a qualitative assessment indicates it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the Company will proceed to the quantitative second step (generally referred to as a "step 1" analysis).

Step 1 of the quantitative test requires comparison of the carrying value of each of the reporting units to the respective fair value, calculated based on weighted income and market-based approaches. If the carrying value of the reporting unit is less than the fair value, no impairment exists. Otherwise, the Company would recognize an impairment charge for the amount by which the carrying amount of a reporting unit exceeds its fair value up to the amount of goodwill allocated to that reporting unit.

The Company's annual assessment of goodwill has historically been completed as of the beginning of the fourth quarter each year. The Company performed its 2025 and 2024 annual assessments as of October 1 of each year and determined that no impairment existed as the estimated fair value of each of the Company's reporting units was in excess of its respective carrying value. Also, no triggering events or changes in circumstances occurred during the period October 1, 2025 through December 31, 2025 that warranted retesting goodwill for impairment.

Embedded Derivatives—Embedded derivatives that are required to be bifurcated from the underlying host instrument are accounted for and valued as a separate financial instrument. These embedded derivatives are bifurcated, accounted for at their estimated fair value, which is based on certain estimates and assumptions, and presented separately on the consolidated statements of financial position. Our valuation of embedded derivatives follows the With and Without method of the income approach, where the value of the derivative is derived by comparing projected cash flows with and without the embedded feature. The discount rate reflects the level of risk associated with these cash flows and is determined based on and evaluation of the Company’s credit risk and market required yields for comparable securities with similar credit risk. To derive a credit rating indication, the Company utilizes the Synthetic Credit Rating Model, and the recovery rate method is employed to establish the Company’s discount rate. Changes in fair value of the embedded derivatives are recognized as a component of other income/expense on the Company’s consolidated statements of operations (Note 16).

Foreign Currency—The Company historically has operations in the United States, Canada, Australia and Europe. In 2025, the Company exited all operations in Europe. The results of its non-U.S. dollar based functional currency operations are translated to U.S. dollars at the average exchange rates during the period. The Company’s assets and liabilities are translated using the exchange rate as of the date of the consolidated statement of financial position and equity is translated using historical rates. Adjustments resulting from the translation of the consolidated financial statements of the Company’s foreign functional currency subsidiaries into U.S. dollars are excluded from the determination of net income (loss) and instead are included in accumulated other comprehensive loss as a separate component of stockholders’ equity. Foreign exchange transaction gains and losses are included in selling, general and administrative expense on the consolidated statements of operations.

Accumulated Other Comprehensive Loss—Accumulated other comprehensive loss, as presented on the consolidated statements of redeemable convertible and redeemable Series A-2 Preferred Stock and stockholders’ equity, consists of unrealized gains and losses on foreign currency translation. Comprehensive income (loss) is not included in the computation of income tax benefit.

Revenue Recognition—Revenue is recognized in accordance with ASC Topic 606, Revenue from Contracts with Customers. The following is considered by the Company in the recognition of revenue under ASC 606:

The Company’s services are performed under two general types of contracts (i) fixed-price and (ii) time-and-materials. Under fixed-price contracts, customers pay an agreed-upon amount for a specified scope of work agreed to in advance of the project. Under time-and-materials contracts, customers pay for the hours worked and resources used based on agreed-upon rates. Certain of the Company’s time-and-materials contracts are subject to maximum contract amounts. The duration of the Company’s contracts ranges from less than one month to over a year, depending on the scope of services provided. Payment terms are agreed upon at the time of contract approval and are typically net 30. Costs to obtain and fulfill contracts associated with system sales are expensed as a cost of revenue when the Company has fulfilled its performance obligations.

The Company accounts for individual promises in contracts as separate performance obligations if the promises are distinct. The assessment requires judgment. The majority of the Company’s contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and is, therefore, not distinct. Certain contracts in the Company’s Measurement and Analysis segment have multiple performance obligations, most commonly due to the contracts providing for multiple laboratory tests which are individual performance obligations.

For the Measurement and Analysis contracts with multiple performance obligations, the Company allocates the transaction price to each performance obligation based on the relative standalone selling price of each performance obligation. The standalone selling price of each performance obligation is generally determined by the observable price of a service when sold separately.

Fixed fee contracts—On the majority of fixed fee contracts, the Company recognizes revenue, over time, using either the proportion of actual costs incurred to the total costs expected to complete the contract performance obligation (cost to cost method), or the time-elapsed basis. The Company determined that the cost to cost method best represents the transfer of services as the proportion closely depicts the efforts or inputs completed towards the satisfaction of a fixed fee contract performance obligation. Under the time-elapsed basis, the arrangement is considered a single performance obligation comprised of a series of distinct services that are substantially the same and that have the same pattern of transfer (i.e. distinct days of service). The Company applies a time-based measure of progress to the total transaction price, which results in ratable recognition over the term of the contract. For a portion of the Company’s laboratory service contracts, revenue is recognized as performance obligations are satisfied over time, with recognition reflecting a series of distinct services using the output method. The Company determined that this method best represents the transfer of services as the customer obtains equal benefit from the service throughout the service period.

There are inherent uncertainties in the estimation process for cost to cost contracts, as the estimation of total contract costs and estimates to complete is complex, subject to many variables, and requires judgment. It is possible that estimates of costs to complete a performance obligation will be revised in the near-term based on actual progress and costs incurred. These uncertainties primarily impact the Company’s contracts in the Remediation and Reuse segment.

Time-and-materials contracts—Time-and-materials contracts contain variable consideration. However, these arrangements qualify for the “Right to Invoice” practical expedient. Under this practical expedient, the Company recognized revenue, over time, in the amount to which the Company has a right to invoice. In addition, the Company is not required to estimate such variable consideration upon inception of the contract and reassess the estimate each reporting period. The Company determined that this method best represents the transfer of services as, upon billing, the Company had a right to consideration from a customer in an amount that directly corresponded with the value to the customer of the Company’s performance completed to date.

Segment Reporting—Operating segments are components of an enterprise for which discrete financial reporting information is available and evaluated regularly by the Chief Operating Decision Maker (CODM) in deciding how to allocate resources and in assessing performance. The Company has identified its Chief Executive Officer as the CODM. The CODM views the Company’s operations and manages the businesses as three operating segments, which are also the Company’s reportable segments: (i) Assessment, Permitting and Response, (ii) Measurement and Analysis, and (iii) Remediation and Reuse.

Stock-Based Compensation—The Company sponsors stock incentive plans that allow for issuance of employee stock options, restricted stock awards, restricted stock units and stock appreciation rights awards.

There are certain awards that were issued to non-employees in exchange for their services and are accounted for under ASC 505, Equity-Based Payments to Non-Employees. ASC 505 requires that the fair value of the equity instruments issued to a non-employee be measured on the earlier of: (i) the performance commitment date or (ii) the date the services required under the arrangement have been completed.

Certain of the performance based restricted stock units will only meet the requirements for establishing a grant date when the final calculated financial performance metrics and the amount of awards have been approved by the Company’s Board of Directors, which will then trigger the service inception date, the fair value of the awards, and the associated expense recognition period.

The fair value of the remaining stock-based payment awards is expensed over the vesting period of each tranche on a straight-line basis. Any modification of an award that increases its fair value will require the Company to recognize additional expense. The fair value of stock options under its employee stock incentive plan are estimated as of the grant date using the Black-Scholes option valuation model, which is affected by its expected dividend yield, expected term and the expected share price volatility of its common shares over the expected term. No dividend rates are used in the calculation as these are not applicable to the Company. Forfeitures are recognized as incurred. Employee options are accounted for in accordance with the guidance set forth by ASC 718, Stock Based Compensation.

Income Taxes—The Company accounts for income taxes under the asset and liability method, which requires recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the period that includes the enacted date.

A valuation allowance is recorded when it is more-likely-than-not some of the deferred tax assets may not be realized. Significant judgment is applied when assessing the need for a valuation allowance and the Company considers all available positive and negative evidence, including future taxable income, reversals of existing deferred tax assets and liabilities and ongoing prudent and feasible tax planning strategies in making such assessment. Should a change in circumstances lead to a change in judgment regarding the utilization of deferred tax assets in future years, the Company will adjust the related valuation allowance in the period such change in circumstances occurs.

For acquired business entities, if the Company identifies changes to acquired deferred tax asset valuation allowances or liabilities related to uncertain tax positions during the measurement period, and they relate to new information obtained about facts and circumstances existing as of the acquisition date, those changes are considered a measurement period adjustment and the offset is recorded to goodwill.

The Company records uncertain tax positions on the basis of the two-step process in which (i) it determines whether it is more-likely-than-not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more-likely-than-not recognition threshold, the Company would recognize the largest amount of tax benefit that is more than 50.0% likely to be realized upon ultimate settlement with the related tax authority. The Company classifies interest and penalties recognized on uncertain tax positions as a component of income tax expense.
v3.25.4
Summary of New Accounting Pronouncements
 12 Months Ended
Dec. 31, 2025
Accounting Standards Update and Change in Accounting Principle [Abstract]  
Summary of New Accounting Pronouncements

3. SUMMARY OF NEW ACCOUNTING PRONOUNCEMENTS

Recently Adopted Accounting Pronouncements

ASU 2023-05 —In August 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-05 Business Combinations — Joint Venture Formations (Subtopic 805-60): Recognition and Initial Measurement, under which an entity that qualifies as either a joint venture or a corporate joint venture is required to apply a new basis of accounting upon the formation of the joint venture. Specifically, the ASU provides that a joint venture or a corporate joint venture must initially measure its assets and liabilities at fair value on the formation date. The amendments in ASU 2023-05 are effective for all joint ventures within the ASU’s scope that are formed on or after January 1, 2025. The Company adopted the standard on January 1, 2025. The adoption of the standard did not have a material impact on the Company's consolidated financial statements.

ASU 2023-09 —In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures, which improves the transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the rate reconciliation and income taxes paid disaggregated by jurisdiction. It also includes certain other amendments to improve the effectiveness of income tax disclosures. ASU 2023-09 is effective for the Company's fiscal year beginning after December 15, 2024 and is being applied using the retrospective approach. The Company adopted the standard on January 1, 2025. The adoption did not have an impact on the recognition or measurement of income taxes in the Company's consolidated financial statements, and only required additional disclosures. The Company updated its income tax disclosures in accordance with the guidance.

Recently Issued Accounting Pronouncements Not Yet Adopted

ASU 2024-03 —In November 2024, the FASB issued ASU 2024-03, Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses (ASU 2024-03), which is intended to improve the disclosures about a public business entity’s expenses and address requests from investors for more detailed information about the types of expenses

in commonly presented expense captions (such as cost of sales; selling, general, and administrative expenses; and research and development). ASU 2024-03 is effective for the Company's fiscal year beginning January 1, 2027 and interim periods within fiscal years beginning after December 15, 2027, and allows the use of a prospective or retrospective approach. The Company plans to adopt the standard on January 1, 2027 and is currently evaluating the impact of the adoption of the standard on its consolidated financial statements.

ASU 2025-06 —In September 2025, the FASB issued ASU 2025-06, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software (ASU 2025-06), which removes all references to software development project stages, making the guidance neutral to different software development methodologies. Under the ASU, software capitalization will begin when management has authorized and committed to funding the software project and it is probable that the project will be completed and the software will be used as intended. ASU 2025-06 is effective for the Company's fiscal year beginning January 1, 2028, and interim periods within fiscal years beginning after December 15, 2027, and allows the use of a prospective, modified transition, or retrospective approach. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of the standard on its consolidated financial statements.
v3.25.4
Revenues and Accounts Receivable
 12 Months Ended
Dec. 31, 2025
Revenues And Accounts Receivable [Abstract]  
Revenues and Accounts Receivable

4. REVENUES AND ACCOUNTS RECEIVABLE

The Company’s main revenue sources derive from the following revenue streams:

Assessment, Permitting and Response Revenues are generated from multidisciplinary environmental consulting services. The majority of the contracts are fixed-price or time-and-material based.

Measurement and Analysis Revenues are generated from emissions sampling, testing and reporting services, leak detection services, ambient air monitoring services and laboratory testing services. The majority of the contracts are fixed-price or time-and-materials based.

Remediation and Reuse Revenues are generated from engineering, design, implementation and operating and maintenance (O&M) services primarily to treat contaminated water and remove contaminants from soil. Engineering, design and implementation contracts are predominantly fixed-fee and time-and-materials based. Services on the majority of O&M contracts are provided under long-term fixed-fee contracts.

Disaggregation of Revenue—The Company disaggregates revenue by its operating segments and geographic location. The Company believes disaggregating revenue into these categories achieves the disclosure objectives to depict how the nature, amount, and uncertainty of revenue and cash flows are affected by economic factors. Disaggregated revenue disclosures are provided in Note 19.

Contract Balances

The Company presents contract balances for unbilled receivables (contract assets), as well as customer advances, deposits and deferred revenue (contract liabilities) within contract assets and accounts payable and other accrued expenses, respectively, on the consolidated statements of financial position. Amounts are generally billed at periodic intervals (e.g. weekly, bi-weekly or monthly) as work progresses in accordance with agreed-upon contractual terms. The Company utilizes the practical expedient to not adjust the promised amount of consideration for the effects of a significant financing component for the arrangements in which the period between when the Company transfers services to a customer and when the customer pays for those services is one year or less. Amounts recorded as unbilled receivables are generally for services the Company is not entitled to bill based on the passage of time. Under certain contracts, billing occurs subsequent to revenue recognition, resulting in contract assets. The Company sometimes receives advances or deposits from customers before revenue is recognized, resulting in contract liabilities.

The following table presents the Company’s contract balances as of December 31:

 

 

 

December 31,

 

 

December 31,

 

 

 

2025

 

 

2024

 

Contract assets

 

$

58,831

 

 

$

52,091

 

Contract liabilities

 

 

14,996

 

 

 

9,297

 

 

Contract assets acquired through business acquisitions amounted to $0.0 million and $2.6 million as of December 31, 2025 and 2024, respectively. No contract liabilities were acquired through business acquisitions as of both December 31, 2025 and 2024.

Revenue recognized during the year ended December 31, 2025, included in the contract liability balance at the beginning of the year was $6.0 million. The revenue recognized from the contract liabilities consisted of the Company satisfying performance obligations during the normal course of business.

Remaining Unsatisfied Performance Obligations

Remaining unsatisfied performance obligations represent the total dollar value of work to be performed on cost to cost contracts awarded and in progress. The amount of remaining unsatisfied performance obligations increases with new contracts or additions to existing contracts and decreases as revenue is recognized on existing contracts. Contracts are included in the amount of remaining unsatisfied performance obligations when an enforceable agreement has been reached. As of December 31, 2025 and 2024, the estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied was approximately $68.4 million and $77.3 million, respectively. As of December 31, 2025, the Company expected to recognize approximately 82% of this amount as revenue within a year, and the remaining 18% to be recognized as revenue beyond one year.

Accounts Receivable, Net

Accounts receivable, net consisted of the following:

 

 

 

December 31, 2025

 

 

December 31, 2024

 

Accounts receivable, invoiced

 

$

163,694

 

 

$

160,976

 

Allowance for doubtful accounts

 

 

(8,314

)

 

 

(2,093

)

Accounts receivable, net

 

$

155,380

 

 

$

158,883

 

The Company had one customer that exceeded 10.0% of its gross receivables as of December 31, 2025 and none as of December 31, 2024. The Company had one customer who accounted for approximately 17.8% of revenue for the year ended December 31, 2025. Revenue from this customer included approximately $112.2 million in emergency and non-emergency response revenue stemming from an environmental incident to which the Company responded. The Company had no customers who accounted for more than 10% of revenue for the year ended December 31, 2024. The Company had one customer who accounted for approximately 10.0% of revenue for the year ended December 31, 2023.

The Company performs ongoing credit evaluations and based on past collection experience, the Company believes that the receivable balances from these largest customers do not represent a significant credit risk.

From time to time, the Company may sell certain accounts receivable to a financial institution on a non-recourse basis for cash, less a discount at a rate that approximates the interest rate on its senior secured credit facility. The Company has no retained interests in the sold receivables and only perform collection and administrative functions for the purchaser. The Company accounts for these receivable transfers as sales under ASC 860, Transfers and Servicing. Receivables sold during the year ended December 31, 2025 was $13.4 million. Proceeds from the sale of receivables approximated their book value and are included in operating cash flows on the Consolidated Statements of Cash Flows. All receivables sold during the year ended December 31, 2025 have been fully collected as of December 31, 2025.

The allowance for doubtful accounts consisted of the following:

 

 

 

Beginning
Balance

 

 

Bad Debt
Expense
(Recovery)

 

 

Charged to
Allowance

 

 

Ending
Balance

 

Year ended December 31, 2025

 

$

2,093

 

 

$

6,713

 

 

$

(492

)

 

$

8,314

 

Year ended December 31, 2024

 

 

2,724

 

 

 

(146

)

 

 

(485

)

 

 

2,093

 

Year ended December 31, 2023

 

 

1,915

 

 

 

3,142

 

 (1)

 

(2,333

)

 (1)

 

2,724

 
(1)
Amount includes $2.2 million of current expected losses on the Discontinued Specialty Lab promissory note receivable as described in Note 8.
v3.25.4
Prepaid and Other Current Assets
 12 Months Ended
Dec. 31, 2025
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]  
Prepaid and Other Current Assets

5. PREPAID AND OTHER CURRENT ASSETS

Prepaid and other current assets consisted of the following:

 

 

 

December 31, 2025

 

 

December 31, 2024

 

Deposits

 

$

967

 

 

$

1,073

 

Prepaid expenses

 

 

11,367

 

 

 

10,223

 

Supplies

 

 

2,625

 

 

 

2,794

 

Prepaid and other current assets

 

$

14,959

 

 

$

14,090

 
v3.25.4
Property and Equipment, Net
 12 Months Ended
Dec. 31, 2025
Property, Plant and Equipment [Abstract]  
Property and Equipment, Net

6. PROPERTY AND EQUIPMENT, NET

Property and equipment are stated at cost or estimated fair value for assets acquired through business combinations. Depreciation and amortization are provided using the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized using the straight-line method over the shorter of the remaining lease term, including options that are deemed to be reasonably assured, or the estimated useful life of the improvement.

Property and equipment, net consisted of the following:

 

 

Estimated Useful Life

 

December 31, 2025

 

 

December 31, 2024

 

Lab and test equipment

7 years

 

$

24,604

 

 

$

24,421

 

Vehicles

5 years

 

 

6,696

 

 

 

6,360

 

Equipment

3-7 years

 

 

70,702

 

 

 

60,763

 

Furniture and fixtures

7 years

 

 

5,322

 

 

 

3,221

 

Leasehold improvements

7 years

 

 

15,335

 

 

 

14,029

 

Aircraft

10-20 years

 

 

12,386

 

 

 

12,386

 

Building

20-39 years

 

 

5,764

 

 

 

5,763

 

 

 

 

140,809

 

 

 

126,943

 

Land

 

 

 

1,089

 

 

 

1,089

 

Construction in progress

 

 

 

1,930

 

 

 

3,993

 

Less: Accumulated depreciation

 

 

 

(79,975

)

 

 

(68,249

)

Total property and equipment—net

 

 

$

63,853

 

 

$

63,776

 

Total depreciation expense for property and equipment, net included on the consolidated statements of operations was $12.3 million, $12.0 million, and $10.3 million for the years ended December 31, 2025, 2024, and 2023, respectively.
v3.25.4
Leases
 12 Months Ended
Dec. 31, 2025
Leases [Abstract]  
Leases

7. LEASES

Leases are classified as either finance or operating leases based on criteria in ASC 842. The Company has finance leases for its vehicle and equipment leases and operating leases for its real estate space and office equipment leases. The Company’s operating and finance leases generally have original lease terms between 1 year and 20 years, and in some instances include one or more options to renew. The Company includes options to extend the lease term if the options are reasonably certain of being exercised. The Company currently considers some of its renewal options to be reasonably certain to be exercised. Some leases also include early termination options, which can be exercised under specific conditions. The Company does not have material residual value guarantees or restrictive covenants associated with its leases.

Finance and operating lease right-of-use (ROU) assets represent the right to use an underlying asset for the lease term, and finance and operating lease liabilities represent the obligation to make lease payments arising from the lease.

The Company calculates the present value of its finance and operating leases using an estimated incremental borrowing rate (IBR), which requires judgment. For real estate operating leases, the Company estimates the IBR based on prevailing market rates for collateralized debt in a similar economic environment with similar payment terms and maturity dates commensurate with the terms of the lease. For all other leases, the Company estimates the IBR based on the stated interest rate on the contract. Since many of the inputs used to calculate the rate implicit in the leases are not readily determinable from the lessee’s perspective, the Company does not use the implicit interest rate.

Certain leases contain variable payments, these payments are expensed as incurred and not included in the Company’s operating lease ROU assets and operating lease liabilities. These amounts primarily include payments for maintenance, utilities, taxes, and insurance and are excluded from the present value of the Company’s lease obligations.

The Company does not record operating lease ROU assets or operating lease liabilities for leases with an initial term of 12 months or less. The Company also combines lease and non-lease components on all new or modified operating leases into a single lease component for all classes of assets.

When a lease is terminated before the expiration of the lease term, irrespective of whether the lease is classified as a finance lease or an operating lease, the lessee would derecognize the ROU asset and corresponding lease liability. Any difference would be recognized as a gain or loss related to the termination of the lease. Similarly, if a lessee is required to make any payments or receives any consideration when terminating the lease, it would include such amounts in the determination of the gain or loss upon termination.

Equipment Line of Credit—The Company has an equipment line of credit, specifically dedicated for the purchases of allowable equipment and related freight, installation costs and taxes paid. As of December 31, 2025, the outstanding balance was $16.1 million on this credit line. Interest on leases financed under this facility is based on the SOFR swap rate on or closest to the closing date. Equipment leased through this line of credit met the finance lease criteria as per ASC 842 and accordingly is accounted for as finance lease ROU assets and finance lease liabilities.

The components of lease expense were as follows:

 

 

 

 

 

For the Twelve Months Ended December 31,

 

 

 

Statement of Operations Location

 

2025

 

 

2024

 

Operating lease cost

 

 

 

 

 

 

 

 

Lease cost

 

Selling, general and administrative expense

 

$

12,511

 

 

$

13,667

 

Variable lease cost

 

Selling, general and administrative expense

 

 

3,036

 

 

 

2,217

 

Total operating lease cost

 

 

 

$

15,547

 

 

$

15,884

 

 

 

 

 

 

 

 

 

Finance lease cost

 

 

 

 

 

 

 

 

Amortization of ROU assets

 

Depreciation and amortization

 

$

8,694

 

 

$

5,814

 

Interest on lease liabilities

 

Interest expense, net

 

 

1,232

 

 

 

611

 

Total finance lease cost

 

 

 

$

9,926

 

 

$

6,425

 

Total lease cost

 

 

 

$

25,473

 

 

$

22,309

 

Supplemental cash flows information related to leases was as follows:

 

 

 

For the Twelve Months Ended December 31,

 

 

 

2025

 

 

2024

 

Cash paid for amounts included in the measurement of lease liabilities:

 

 

 

 

 

 

Operating cash flows used in operating leases

 

$

13,777

 

 

$

13,202

 

Operating cash flows used for interest related to finance leases

 

 

1,256

 

 

 

661

 

Financing cash flows used in finance leases

 

 

6,368

 

 

 

5,489

 

Lease liabilities arising from new ROU assets:

 

 

 

 

 

 

Operating leases

 

 

9,204

 

 

 

20,951

 

Finance leases

 

 

22,133

 

 

 

8,841

 

Weighted average remaining lease terms and weighted average discount rates were:

 

 

 

December 31, 2025

 

 

 

Operating Leases

 

 

Finance Leases

 

Weighted average remaining lease term (years)

 

 

4.9

 

 

 

9.7

 

Weighted average discount rate

 

 

5.1

%

 

 

6.7

%

 

 

 

 

 

 

 

 

 

December 31, 2024

 

 

 

Operating Leases

 

 

Finance Leases

 

Weighted average remaining lease term (years)

 

 

4.6

 

 

 

3.7

 

Weighted average discount rate

 

 

4.8

%

 

 

6.7

%

 

The following is a schedule by year of the maturities of lease liabilities with original terms in excess of one year:

 

 

Operating Leases

 

 

Finance Leases

 

2026

 

$

12,394

 

 

$

8,479

 

2027

 

 

9,542

 

 

 

7,070

 

2028

 

 

7,868

 

 

 

5,405

 

2029

 

 

6,069

 

 

 

3,749

 

2030

 

 

2,839

 

 

 

1,947

 

2031 and thereafter

 

 

5,865

 

 

 

18,882

 

Total undiscounted future minimum lease payments

 

$

44,577

 

 

$

45,532

 

Less imputed interest

 

 

(5,627

)

 

 

(13,750

)

Total discounted future minimum lease payments

 

$

38,950

 

 

$

31,782

 
v3.25.4
Business Acquisitions and Dispositions
 12 Months Ended
Dec. 31, 2025
Business Combination [Abstract]  
Business Acquisitions and Dispositions

8. BUSINESS ACQUISITIONS AND DISPOSITIONS

In line with the Company’s strategic growth initiatives, the Company acquired a number of businesses during the years ended December 31, 2024 and 2023. The Company did not complete an acquisition in the year ended December 31, 2025.

The results of each of those acquired businesses are included in the consolidated financial statements beginning on the respective acquisition dates. Each transaction qualified as an acquisition of a business and was accounted for as a business combination. All acquisitions resulted in the recognition of goodwill. The Company paid these premiums resulting in such goodwill for a number of reasons, including expected synergies from combining operations of the acquiree and the Company while also growing the Company’s customer base, acquiring assembled workforces, expanding its presence in certain markets and expanding and advancing its product and service offerings. The Company recorded the assets acquired and liabilities assumed at their acquisition date fair value, with the difference between the fair value of the net assets acquired and the acquisition consideration reflected as goodwill.

The identifiable intangible assets for acquisitions are valued using the excess earnings method discounted cash flow approach for customer relationships, the relief from royalty method for trade names, external proprietary software and developed technology, the “with and without” method for covenants not to compete and the replacement cost method for the internal proprietary software by incorporating Level 3 inputs as described under the fair value hierarchy of ASC 820. These unobservable inputs reflect the Company’s own assumptions about which assumptions market participants would use in pricing an asset on a non-recurring basis. These assets will be amortized over their respective estimated useful lives.

Other purchase price obligations (primarily deferred purchase price liabilities and target working capital liabilities or receivables) are included on the consolidated statements of financial position in accounts payable and other accrued liabilities, other non-current liabilities or accounts receivable, net in the case of working capital deficits. Contingent consideration outstanding from acquisitions are included on the consolidated statements of financial position in business acquisition contingent consideration, current or in business acquisitions contingent consideration, long-term. The contingent consideration elements of the purchase price of the acquisitions are related to earn-outs which are based on the expected achievement of revenue or earnings thresholds as of the date of the acquisition and for which the maximum potential amount is limited.

The Company considers several factors when determining whether or not contingent consideration liabilities are part of the purchase price, including the following: (i) the valuation of its acquisitions is not supported solely by the initial consideration paid, (ii) the former stockholders of acquired companies that remain as key employees receive compensation other than contingent consideration payments at a reasonable level compared with the compensation of the Company’s other key employees and (iii) contingent consideration payments are not affected by employment termination. The Company reviews and assesses the estimated fair value of contingent consideration at each reporting period.

The Company may be required to make up to $17.6 million in aggregate earn-out payments between the years 2026 and 2027, of which up to $5.1 million may be paid only in cash, up to $2.8 million may be paid only in common stock and up to $9.7 million may be paid, at the Company's option, in cash or common stock.

Transaction costs related to business combinations totaled $1.8 million, $7.8 million and $6.9 million for the years ended December 31, 2025, 2024, and 2023, respectively. These costs are expensed within selling, general and administrative expense in the accompanying consolidated statements of operations.

The Company did not acquire intangible assets during 2025. The weighted average useful lives of identifiable intangible assets by major intangible asset class acquired during 2024 and 2023 is as follows:

 

 

2024

 

 

2023

 

Customer relationships

 

8.2

 

 

 

9.4

 

Covenants not to compete

 

5.0

 

 

 

4.9

 

Trade names

 

2.0

 

 

 

1.8

 

Proprietary software

 

—

 

 

 

3.0

 

Weighted average

 

5.3

 

 

 

4.7

 

2024 Acquisitions

Epic Environmental Pty LTD (Epic)—In January 2024, the Company completed the acquisition of Epic by acquiring 100% of its common stock. Epic is an environmental consultancy, based in Brisbane, Australia, and serving clients across Australia.

Two Dot Consulting, LLC (2DOT)—In February 2024, the Company completed the acquisition of 2DOT by acquiring 100% of its membership interests. 2DOT is a leading environmental consultancy in the Rocky Mountain and adjacent regions, and is based in Denver, Colorado.

Engineering & Technical Associates, Inc. (ETA)—In April 2024, the Company acquired substantially all of the assets of ETA. ETA is a niche consulting firm focusing on providing process safety management, process hazardous analysis, and other safety-focused services to industrial clients throughout the United States.

Paragon Soil and Environmental Consulting Inc. (Paragon)—In May 2024, the Company completed the acquisition of Paragon by acquiring 100% of its ownership and interest. Paragon is an environmental consulting firm that provides services for clients across western Canada.

Spirit Environmental, LLC. (Spirit)—In July 2024, the Company completed the acquisition of Spirit by acquiring 100% of its membership interests. Spirit is a leading environmental consultant specializing in air permitting and compliance services across the central U.S. Spirit is based in Houston, Texas.

Origins Laboratory, Inc. (Origins)—In September 2024, the Company acquired substantially all of the assets of Origins. Origins is an accredited environmental analytical testing laboratory based in Denver, Colorado.

The upfront cash payment made to acquire the acquisitions completed during 2024 was funded through cash on hand and borrowings under our revolving line of credit. The other purchase price components mainly consist of deferred purchase price liabilities and working capital amounts.

Goodwill associated with these acquisitions except for Epic are deductible for income tax purposes.

Epic, 2DOT, and Paragon are included in the Remediation and Reuse segment, ETA and Spirit are included in the Assessment, Permitting and Response segment, and Origins is included in the Measurements and Analysis segment.

The following table summarizes the final elements of the purchase price of the acquisitions completed during 2024:

 

 

 

Cash

 

 

Common Stock

 

 

Other Purchase Price Components

 

 

Contingent Consideration

 

 

Total Purchase Price

 

Epic

 

$

19,914

 

 

$

4,748

 

 

$

419

 

 

$

11,113

 

 

$

36,194

 

2DOT

 

 

39,393

 

 

 

1,832

 

 

 

(660

)

 

 

—

 

 

 

40,565

 

ETA

 

 

1,600

 

 

 

—

 

 

 

400

 

 

 

—

 

 

 

2,000

 

Paragon

 

 

10,773

 

 

 

2,691

 

 

 

125

 

 

 

—

 

 

 

13,589

 

Spirit

 

 

16,027

 

 

 

1,441

 

 

 

95

 

 

 

10,308

 

 

 

27,871

 

Origins

 

 

27,414

 

 

 

—

 

 

 

220

 

 

 

8,000

 

 

 

35,634

 

Total

 

$

115,121

 

 

$

10,712

 

 

$

599

 

 

$

29,421

 

 

$

155,853

 

 

The final purchase price attributable to the 2024 acquisitions was allocated as follows:

 

 

 

Epic (As Initially Reported)

 

 

Epic Measurement Period Adjustments

 

 

Epic (As Adjusted)

 

 

2DOT (As Initially Reported)

 

 

2DOT Measurement Period Adjustments

 

 

2DOT (As Adjusted)

 

 

ETA

 

 

Paragon

 

 

Spirit (As Initially Reported)

 

 

Spirit Measurement Period Adjustments

 

 

Spirit (As Adjusted)

 

 

Origins (As Initially Reported)

 

 

Origins Measurement Period Adjustments

 

 

Origins (As Adjusted)

 

 

Total

 

Cash

 

$

1,045

 

 

$

—

 

 

$

1,045

 

 

$

143

 

 

$

—

 

 

$

143

 

 

$

—

 

 

$

242

 

 

$

605

 

 

$

—

 

 

$

605

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

2,035

 

Accounts receivable and contract assets

 

 

1,772

 

 

 

—

 

 

 

1,772

 

 

 

740

 

 

 

—

 

 

 

740

 

 

 

—

 

 

 

3,188

 

 

 

2,393

 

 

 

—

 

 

 

2,393

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

8,093

 

Other current assets

 

 

78

 

 

 

—

 

 

 

78

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

85

 

 

 

119

 

 

 

—

 

 

 

119

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

282

 

Current assets

 

$

2,895

 

 

$

—

 

 

$

2,895

 

 

$

883

 

 

$

—

 

 

$

883

 

 

$

—

 

 

$

3,515

 

 

$

3,117

 

 

$

—

 

 

$

3,117

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

10,410

 

Property and equipment

 

 

43

 

 

 

—

 

 

 

43

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

341

 

 

 

145

 

 

 

—

 

 

 

145

 

 

 

1,787

 

 

 

—

 

 

 

1,787

 

 

 

2,316

 

Operating lease right-of-use asset

 

 

280

 

 

 

—

 

 

 

280

 

 

 

301

 

 

 

—

 

 

 

301

 

 

 

—

 

 

 

1,798

 

 

 

693

 

 

 

—

 

 

 

693

 

 

 

552

 

 

 

—

 

 

 

552

 

 

 

3,624

 

Customer relationships

 

 

12,053

 

 

 

—

 

 

 

12,053

 

 

 

9,521

 

 

 

—

 

 

 

9,521

 

 

 

—

 

 

 

4,209

 

 

 

4,090

 

 

 

—

 

 

 

4,090

 

 

 

7,305

 

 

 

—

 

 

 

7,305

 

 

 

37,178

 

Trade names

 

 

523

 

 

 

—

 

 

 

523

 

 

 

200

 

 

 

—

 

 

 

200

 

 

 

—

 

 

 

350

 

 

 

280

 

 

 

—

 

 

 

280

 

 

 

332

 

 

 

—

 

 

 

332

 

 

 

1,685

 

Covenants not to compete

 

 

1,817

 

 

 

—

 

 

 

1,817

 

 

 

2,940

 

 

 

—

 

 

 

2,940

 

 

 

—

 

 

 

45

 

 

 

700

 

 

 

—

 

 

 

700

 

 

 

87

 

 

 

—

 

 

 

87

 

 

 

5,589

 

Goodwill

 

 

25,102

 

 

 

(168

)

 

 

24,934

 

 

 

27,273

 

 

 

44

 

 

 

27,317

 

 

 

2,000

 

 

 

6,444

 

 

 

18,285

 

 

 

2,051

 

 

 

20,336

 

 

 

25,903

 

 

 

220

 

 

 

26,123

 

 

 

107,154

 

Total assets

 

$

42,713

 

 

$

(168

)

 

$

42,545

 

 

$

41,118

 

 

$

44

 

 

$

41,162

 

 

$

2,000

 

 

$

16,702

 

 

$

27,310

 

 

$

2,051

 

 

$

29,361

 

 

$

35,966

 

 

$

220

 

 

$

36,186

 

 

$

167,956

 

Current liabilities

 

 

1,994

 

 

 

—

 

 

 

1,994

 

 

 

404

 

 

 

—

 

 

 

404

 

 

 

—

 

 

 

1,572

 

 

 

1,490

 

 

 

—

 

 

 

1,490

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

5,460

 

Deferred tax liability

 

 

4,214

 

 

 

—

 

 

 

4,214

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

4,214

 

Operating lease liability—net of current portion

 

 

—

 

 

 

—

 

 

 

—

 

 

 

193

 

 

 

—

 

 

 

193

 

 

 

—

 

 

 

1,513

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

552

 

 

 

—

 

 

 

552

 

 

 

2,258

 

Other non-current liabilities

 

 

143

 

 

 

—

 

 

 

143

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

28

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

171

 

Total liabilities

 

$

6,351

 

 

$

—

 

 

$

6,351

 

 

$

597

 

 

$

—

 

 

$

597

 

 

$

—

 

 

$

3,113

 

 

$

1,490

 

 

$

—

 

 

$

1,490

 

 

$

552

 

 

$

—

 

 

$

552

 

 

$

12,103

 

Purchase price

 

$

36,362

 

 

$

(168

)

 

$

36,194

 

 

$

40,521

 

 

$

44

 

 

$

40,565

 

 

$

2,000

 

 

$

13,589

 

 

$

25,820

 

 

$

2,051

 

 

$

27,871

 

 

$

35,414

 

 

$

220

 

 

$

35,634

 

 

$

155,853

 

For the acquisitions completed during the year ended December 31, 2024, the results of operations since the acquisition dates have been combined with those of the Company. The Company’s consolidated statement of operations for the year ended December 31, 2024 includes revenue and pre-tax income of $44.6 million and $8.5 million, respectively, related to these acquisitions.

2023 Acquisitions

Frontier Analytical Laboratories (Frontier) —In January 2023, the Company completed the acquisition of Frontier by acquiring certain of its assets and operations. Frontier is a specialized environmental laboratory based in El Dorado Hills, CA.

Environmental Alliance, Inc. (EAI)—In February 2023, the Company completed the acquisition of EAI by acquiring 100.0% of its common stock. EAI provides environmental remediation and consulting services, and is based in Wilmington, DE.

GreenPath Energy LTD (GreenPath) —In May 2023, the Company completed the acquisition of GreenPath by acquiring 100.0% of its common stock. GreenPath is a leading optical gas imaging and leak detection and management services firm and is based in Calgary, Canada.

Matrix Solutions, Inc. (Matrix) —In June 2023, the Company completed the acquisition of Matrix by acquiring 100.0% of its common stock. Matrix is one of Canada’s leading environmental consulting and engineering companies and is based in Calgary, Canada.

Vandrensning ApS. (Vandrensning) —In July 2023, the Company completed the acquisition of Vandrensning by acquiring 100.0% of its common stock. Vandrensning, based outside Copenhagen, Denmark, specializes in water treatment solutions.

The upfront cash payment made to acquire all of the 2023 acquisitions was funded through cash on hand. The other purchase price components mainly consisted of deferred purchase price liabilities and working capital amounts.

Goodwill associated with the Frontier acquisition is deductible for income tax purposes.

Frontier and GreenPath are included in Measurement and Analysis segment. EAI, Matrix and Vandrensning are included in Remediation and Reuse segment.

The following table summarizes the final elements of the purchase price of the acquisitions completed during 2023:

 

 

Cash

 

 

Common Stock

 

 

Other Purchase Price Components

 

 

Contingent Consideration

 

 

Total Purchase Price

 

2023 Acquisitions

 

$

68,640

 

 

$

2,598

 

 

$

1,603

 

 

$

1,096

 

 

$

73,937

 

 

The final purchase price attributable to the 2023 acquisitions was allocated as follows:

 

 

2023 Acquisitions (As Initially Reported)

 

 

2024 Measurement Period Adjustments

 

 

2024 (Final Amount)

 

Cash

 

$

2,453

 

 

 

—

 

 

$

2,453

 

Accounts receivable and contract assets

 

 

19,174

 

 

 

—

 

 

 

19,174

 

Other current assets

 

 

2,185

 

 

 

—

 

 

 

2,185

 

Current assets

 

 

23,812

 

 

 

—

 

 

 

23,812

 

Property and equipment

 

 

3,936

 

 

 

—

 

 

 

3,936

 

Operating lease right-of-use asset

 

 

4,825

 

 

 

—

 

 

 

4,825

 

Customer relationships

 

 

19,962

 

 

 

—

 

 

 

19,962

 

Trade names

 

 

2,373

 

 

 

—

 

 

 

2,373

 

Covenants not to compete

 

 

2,708

 

 

 

—

 

 

 

2,708

 

Other intangible assets

 

 

444

 

 

 

—

 

 

 

444

 

Goodwill

 

 

40,786

 

 

 

(866

)

 

 

39,920

 

Total assets

 

 

98,846

 

 

 

(866

)

 

 

97,980

 

Current liabilities

 

 

11,557

 

 

 

—

 

 

 

11,557

 

Operating lease liability—net of current portion

 

 

10,357

 

 

 

—

 

 

 

10,357

 

Deferred tax liability

 

 

1,999

 

 

 

—

 

 

 

1,999

 

Other non-current liabilities

 

 

130

 

 

 

—

 

 

 

130

 

Total liabilities

 

 

24,043

 

 

 

—

 

 

 

24,043

 

Purchase price

 

$

74,803

 

 

$

(866

)

 

$

73,937

 

For the acquisitions completed during the year ended December 31, 2023, the results of operations since the acquisition dates have been combined with those of the Company. The Company’s consolidated statement of operations for the year ended December 31, 2023 includes revenue and pre-tax income of $69.1 million and $8.8 million, respectively, related to these acquisitions.

Supplemental Unaudited Pro-Forma—The unaudited consolidated financial information summarized in the following table gives effect to the 2024 and 2023 acquisitions assuming they occurred on January 1, 2023. These unaudited consolidated pro forma operating results include results from certain acquired companies that have not been audited and whose accounting policies prior to acquisition may differ from those of the Company. As a result, these unaudited consolidated pro forma operating results may not be comparable to revenues and earnings had these consolidated pro forma results been audited and consistent accounting policies applied. These unaudited consolidated pro forma operating results do not assume any impact from revenue, cost or other operating synergies that are expected or may have been realized as a result of the acquisitions. These unaudited consolidated pro forma operating results are presented for illustrative purposes only and are not indicative of the operating results that would have been achieved had the acquisitions occurred on January 1, 2023, nor does the information project results for any future period.

 

 

 

For the Twelve Months Ended December 31,

 

 

 

As reported

 

 

Acquisitions Pro-Forma (Unaudited)

 

 

Consolidated Pro-Forma (Unaudited)

 

2025

 

 

 

 

 

 

 

 

 

Revenues

 

$

830,538

 

 

$

—

 

 

$

830,538

 

Net (loss)

 

$

(843

)

 

$

—

 

 

$

(843

)

2024

 

 

 

 

 

 

 

 

 

Revenues

 

$

696,395

 

 

$

24,559

 

 

$

720,954

 

Net (loss) income

 

$

(62,314

)

 

$

9,413

 

 

$

(52,901

)

2023

 

 

 

 

 

 

 

 

 

Revenues

 

$

624,208

 

 

$

65,798

 

 

$

690,006

 

Net (loss) income

 

$

(30,859

)

 

$

8,110

 

 

$

(22,749

)

 

Disposition

During 2025, the Company exited all operations in Europe, which included the sale of its business in Denmark for cash and a minority ownership interest in the acquiror. The Company's European results of operations, exit costs and proceeds from the sale were immaterial in all periods presented. The disposition of this business, which was part of the Company's Remediation and Reuse segment, did not represent a strategic shift that had a major effect on the Company’s operations and financial results, therefore it did not meet the requirements to be classified as discontinued operations.

During the first quarter of 2023, the Company determined to discontinue one of its non-core specialty service lines within the lab testing business (Discontinued Specialty Lab). On December 29, 2023, the Company sold the assets of the Discontinued Specialty Lab for a total sales price of $4.8 million, of which $0.5 million was received in cash and $4.3 million was issued as a promissory note receivable. The Company recorded a gain on the sale of $1.8 million, which is included in selling, general and administrative expense on the consolidated statements of operations and comprehensive loss. Due to the buyers' limited credit history, the Company recorded a current expected loss of $2.2 million, which is included as part of selling, general, and administrative expense on the consolidated statements of operations and comprehensive loss. The Discontinued Specialty Lab performance was sporadic and its service offering was non-core to the Company’s business. The discontinuation of this specialty service line, which was part of the Company's Measurement and Analysis segment, did not represent a strategic shift that had a major effect on the Company’s operations and financial results, therefore it did not meet the requirements to be classified as discontinued operations.

v3.25.4
Goodwill and Intangible Assets
 12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill and Intangible Assets

9. GOODWILL AND INTANGIBLE ASSETS

Amounts related to goodwill are as follows:

 

 

 

Assessment, Permitting and Response

 

 

Measurement and Analysis

 

 

Remediation and Reuse

 

 

Total

 

Balance as of December 31, 2024

 

$

205,231

 

 

$

118,860

 

 

$

143,698

 

 

$

467,789

 

Acquisitions measurement period adjustments, net of foreign currency translation

 

 

1,501

 

 

 

220

 

 

 

(80

)

 

 

1,641

 

Goodwill disposed during the period(1)

 

 

—

 

 

 

—

 

 

 

(2,644

)

 

 

(2,644

)

Balance as of December 31, 2025

 

$

206,732

 

 

$

119,080

 

 

$

140,974

 

 

$

466,786

 

 

(1) Goodwill disposed during the period is due to the disposition of the Company's business in Denmark

Amounts related to finite-lived intangible assets are as follows:

 

December 31, 2025

 

Estimated Useful Life

 

Gross Balance

 

 

Accumulated Amortization

 

 

Total Intangible Assets—Net

 

Customer relationships

 

2-15 years

 

$

264,564

 

 

$

160,459

 

 

$

104,105

 

Covenants not to compete

 

4-5 years

 

 

41,418

 

 

 

36,293

 

 

 

5,125

 

Trade names

 

1-5 years

 

 

25,917

 

 

 

25,441

 

 

 

476

 

Proprietary software

 

3-5 years

 

 

31,982

 

 

 

25,912

 

 

 

6,070

 

Patent

 

16 years

 

 

17,479

 

 

 

6,872

 

 

 

10,607

 

Total other intangible assets, net

 

 

 

$

381,360

 

 

$

254,977

 

 

$

126,383

 

 

 

 

 

 

 

 

 

 

 

 

 

December 31, 2024

 

Estimated Useful Life

 

Gross Balance

 

 

Accumulated Amortization

 

 

Total Intangible Assets—Net

 

Customer relationships

 

2-15 years

 

$

264,477

 

 

$

138,787

 

 

$

125,690

 

Covenants not to compete

 

4-5 years

 

 

41,758

 

 

 

33,898

 

 

 

7,860

 

Trade names

 

1-5 years

 

 

25,939

 

 

 

23,375

 

 

 

2,564

 

Proprietary software

 

3-5 years

 

 

28,428

 

 

 

23,489

 

 

 

4,939

 

Patent

 

16 years

 

 

17,479

 

 

 

5,776

 

 

 

11,703

 

Total other intangible assets, net

 

 

 

$

378,081

 

 

$

225,325

 

 

$

152,756

 

 

Intangible assets with finite lives are stated at cost, less accumulated amortization and impairment losses, if any. These intangible assets are amortized using the straight-line method over the estimated useful lives of the assets.

Amortization expense for the years ended December 31, 2025, 2024, and 2023 was $29.9 million, $34.9 million and $30.1 million, respectively.

Future amortization expense is estimated to be as follows for each of the five following years and thereafter ending December 31:

 

December 31,

 

 

 

2026

 

$

25,371

 

2027

 

 

24,258

 

2028

 

 

18,664

 

2029

 

 

12,773

 

2030

 

 

9,418

 

Thereafter

 

 

35,899

 

Total

 

$

126,383

 
v3.25.4
Accounts Payable and Other Accrued Liabilities
 12 Months Ended
Dec. 31, 2025
Payables and Accruals [Abstract]  
Accounts Payable and Other Accrued Liabilities

10. ACCOUNTS PAYABLE AND OTHER ACCRUED LIABILITIES

Accounts payable and other accrued liabilities consisted of the following:

 

 

 

December 31, 2025

 

 

December 31, 2024

 

Accounts payable

 

$

34,806

 

 

$

33,424

 

Accrued expenses

 

 

18,373

 

 

 

16,190

 

Contract liabilities

 

 

14,996

 

 

 

9,297

 

Other current liabilities

 

 

3,603

 

 

 

4,793

 

Total accounts payable and other accrued liabilities

 

$

71,778

 

 

$

63,704

 
v3.25.4
Accrued Payroll and Benefits
 12 Months Ended
Dec. 31, 2025
Statement of Financial Position [Abstract]  
Accrued Payroll and Benefits

11. ACCRUED PAYROLL AND BENEFITS

Accrued payroll and benefits consisted of the following:

 

 

 

December 31, 2025

 

 

December 31, 2024

 

Accrued bonuses

 

$

28,568

 

 

$

14,433

 

Accrued payroll

 

 

13,501

 

 

 

11,969

 

Accrued paid time off

 

 

3,603

 

 

 

4,214

 

Accrued medical

 

 

2,305

 

 

 

1,589

 

Accrued other

 

 

4,796

 

 

 

2,043

 

Total accrued payroll and benefits

 

$

52,773

 

 

$

34,248

 
v3.25.4
Income Taxes
 12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Income Taxes

12. INCOME TAXES

The following is a geographical breakdown of income (loss) before the provision for income (loss) taxes as of December 31:

 

 

 

2025

 

 

2024

 

 

2023

 

Pre-tax income (loss):

 

 

 

 

 

 

 

 

 

Federal

 

$

17,189

 

 

$

(54,860

)

 

$

(35,111

)

Foreign

 

 

(5,968

)

 

 

542

 

 

 

3,272

 

Total

 

$

11,221

 

 

$

(54,318

)

 

$

(31,839

)

 

Income tax expense (benefit) for the years ended December 31, is comprised of the following:

 

 

 

2025

 

 

2024

 

 

2023

 

Current:

 

 

 

 

 

 

 

 

 

Federal

 

$

29

 

 

$

244

 

 

$

—

 

State

 

 

2,271

 

 

 

817

 

 

 

1,840

 

Foreign

 

 

1,081

 

 

 

1,887

 

 

 

(1,131

)

Total current tax expense

 

 

3,381

 

 

 

2,948

 

 

 

709

 

Deferred:

 

 

 

 

 

 

 

 

 

Federal

 

 

10,053

 

 

 

1,160

 

 

 

(438

)

State

 

 

(452

)

 

 

1,850

 

 

 

(960

)

Foreign

 

 

(918

)

 

 

2,038

 

 

 

(291

)

Total deferred tax expense

 

 

8,683

 

 

 

5,048

 

 

 

(1,689

)

Total:

 

 

 

 

 

 

 

 

 

Federal

 

 

10,082

 

 

 

1,404

 

 

 

(438

)

State

 

 

1,819

 

 

 

2,667

 

 

 

880

 

Foreign

 

 

163

 

 

 

3,925

 

 

 

(1,422

)

Income tax expense (benefit)

 

$

12,064

 

 

$

7,996

 

 

$

(980

)

The Company’s deferred taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes, and includes the impact of any valuation allowance on net deferred tax assets.

Significant components of the Company’s deferred tax assets and liabilities as of December 31, are as follows:

 

 

 

2025

 

 

2024

 

Deferred tax assets:

 

 

 

 

 

 

Net operating losses

 

$

11,000

 

 

$

14,021

 

Section 163(j) interest limitation

 

 

3,058

 

 

 

7,627

 

Equity compensation

 

 

2,063

 

 

 

7,669

 

Contingent consideration

 

 

8,621

 

 

 

9,007

 

Lease liabilities

 

 

17,182

 

 

 

(15,274

)

Accrued compensation

 

 

6,991

 

 

 

4,117

 

Transaction costs

 

 

2,384

 

 

 

2,525

 

Section 174 research & experimental

 

 

648

 

 

 

1,312

 

Interest rate swap

 

 

106

 

 

 

(402

)

Other

 

 

8,067

 

 

 

6,593

 

Total deferred tax asset

 

 

60,120

 

 

 

37,195

 

Deferred tax liabilities:

 

 

 

 

 

 

Intangible assets

 

 

(24,650

)

 

 

(22,399

)

Property and equipment

 

 

(14,104

)

 

 

(13,944

)

ROU assets

 

 

(18,027

)

 

 

14,986

 

Other

 

 

(90

)

 

 

(1,529

)

Total deferred tax liability

 

 

(56,871

)

 

 

(22,886

)

Valuation allowance

 

 

(25,066

)

 

 

(27,621

)

Net deferred tax liability

 

$

(21,817

)

 

$

(13,312

)

 

The effective tax rate of the Company's provision (benefit) for income taxes differs from the federal statutory rate for the years ended December 31, are as follows:

 

 

 

2025

 

 

2024

 

 

2023

 

 

US federal statutory tax rate

 

$

2,356

 

 

 

21.00

 

%

$

(11,408

)

 

 

21.00

 

%

$

(6,686

)

 

 

21.00

 

%

State and local income taxes, net of federal income tax effect(1)

 

 

1,150

 

 

 

10.25

 

 

 

2,511

 

 

 

(4.62

)

 

 

477

 

 

 

(1.50

)

 

Effect of cross-border tax laws

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Global intangible low-taxed income

 

 

316

 

 

 

2.81

 

 

 

1,410

 

 

 

(2.60

)

 

 

1,067

 

 

 

(3.35

)

 

US tax impact of foreign branches

 

 

(174

)

 

 

(1.55

)

 

 

(501

)

 

 

0.92

 

 

 

(148

)

 

 

0.47

 

 

Sale of Denmark business

 

 

566

 

 

 

5.05

 

 

 

—

 

 

 

0.00

 

 

 

—

 

 

 

0.00

 

 

Tax credits

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Federal research and development credit

 

 

(1,139

)

 

 

(10.15

)

 

 

—

 

 

 

0.00

 

 

 

—

 

 

 

0.00

 

 

Change in valuation allowance

 

 

157

 

 

 

1.40

 

 

 

(911

)

 

 

1.68

 

 

 

(4,421

)

 

 

13.88

 

 

Nondeductible items

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Equity compensation

 

 

7,636

 

 

 

68.06

 

 

 

1,519

 

 

 

(2.80

)

 

 

539

 

 

 

(1.69

)

 

Mark to market - fair value derivative

 

 

(4,247

)

 

 

(37.85

)

 

 

253

 

 

 

(0.47

)

 

 

(1,410

)

 

 

4.43

 

 

Meals

 

 

365

 

 

 

3.25

 

 

 

365

 

 

 

(0.67

)

 

 

526

 

 

 

(1.65

)

 

Transaction expense - deemed contribution to controlled foreign corporation

 

 

—

 

 

 

0.00

 

 

 

318

 

 

 

(0.59

)

 

 

492

 

 

 

(1.55

)

 

Worldwide changes in unrecognized tax benefits

 

 

624

 

 

 

5.56

 

 

 

—

 

 

 

0.00

 

 

 

—

 

 

 

0.00

 

 

Other

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Federal deferred tax adjustments

 

 

1,346

 

 

 

12.00

 

 

 

10,659

 

 

 

(19.62

)

 

 

9,606

 

 

 

(30.17

)

 

Federal tax return true up

 

 

222

 

 

 

1.98

 

 

 

(940

)

 

 

1.73

 

 

 

448

 

 

 

(1.41

)

 

Section 162(m) compensation deduction limitation

 

 

1,229

 

 

 

10.95

 

 

 

183

 

 

 

(0.34

)

 

 

22

 

 

 

(0.07

)

 

Other

 

 

239

 

 

 

2.13

 

 

 

725

 

 

 

(1.34

)

 

 

539

 

 

 

(1.69

)

 

Foreign tax effects

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Canada

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rate differential

 

 

(203

)

 

 

(1.81

)

 

 

18

 

 

 

(0.03

)

 

 

153

 

 

 

(0.48

)

 

Return-to-provision adjustments

 

 

756

 

 

 

6.74

 

 

 

2,953

 

 

 

(5.44

)

 

 

(466

)

 

 

1.46

 

 

Impact of scientific research and experimental development credits

 

 

(641

)

 

 

(5.72

)

 

 

269

 

 

 

(0.50

)

 

 

(2,028

)

 

 

6.37

 

 

Other

 

 

67

 

 

 

0.60

 

 

 

(101

)

 

 

0.19

 

 

 

11

 

 

 

(0.04

)

 

Australia

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rate differential

 

 

999

 

 

 

8.90

 

 

 

172

 

 

 

(0.32

)

 

 

46

 

 

 

(0.14

)

 

Change in valuation allowance

 

 

—

 

 

 

0.00

 

 

 

—

 

 

 

0.00

 

 

 

(153

)

 

 

0.48

 

 

Other foreign jurisdictions

 

 

440

 

 

 

3.91

 

 

 

502

 

 

 

(0.63

)

 

 

406

 

 

 

(1.02

)

 

Total

 

$

12,064

 

 

 

107.51

 

%

$

7,996

 

 

 

(14.45

)

%

$

(980

)

 

 

3.33

 

%

 

(1) In each year, the state and local income taxes which comprise the majority of the state and local income taxes, net of federal effect category are California and Pennsylvania.

The cash paid for income taxes (net of refunds) during the year was as follows:

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

Federal

 

$

540

 

 

$

—

 

 

$

—

 

State and local

 

 

 

 

 

 

 

 

 

Pennsylvania

 

 

213

 

 

 

307

 

 

 

614

 

Texas

 

 

200

 

 

 

219

 

 

 

(129

)

Alabama

 

 

613

 

 

 

89

 

 

 

9

 

California

 

 

1,045

 

 

 

87

 

 

 

10

 

Other

 

 

1,200

 

 

 

1,572

 

 

 

493

 

Total state and local

 

 

3,271

 

 

 

2,274

 

 

 

997

 

Foreign

 

 

 

 

 

 

 

 

 

Canada

 

 

195

 

 

 

1,232

 

 

 

—

 

Australia

 

 

1,499

 

 

 

688

 

 

 

—

 

Total foreign

 

 

1,694

 

 

 

1,920

 

 

 

—

 

Total

 

$

5,505

 

 

$

4,194

 

 

$

997

 

The Company elected to account for the global intangible low-taxed income inclusion as a period cost.

The Company recorded a valuation allowance against its U.S., Germany, Belgium, Sweden, and Denmark net deferred tax assets as realization of such assets is not more likely than not. The impact of indefinite lived deferred items was considered in recording such valuation allowance. The decrease in the Company’s valuation allowance was $2.6 million during the year ended December 31, 2025. The increase in the Company's valuation allowance was $3.5 million during the year ended December 31, 2024.

As of December 31, 2025, US federal and state net operating loss carryforwards of approximately $31.9 million and $94.2 million are available to offset future federal and state taxable income, respectively.

Federal net operating loss carryforwards carry forward indefinitely while the Company’s state net operating loss carryforwards will begin to expire during various years, dependent on the jurisdiction.

Additionally, as of December 31, 2025, the Company has federal and state research and development credit carryforwards of $0.8 million and $0.1 million, respectively. The federal and state credits will begin to expire in 2044, unless previously utilized.

The Company records uncertain tax positions in accordance with ASC 740, on the basis of a two-step process in which (i) the Company determines whether it is more likely than not a tax position will be sustained on the basis of the technical merits of such position and (ii) for those tax positions meeting the more-likely-than-not recognition threshold, the Company would recognize the largest amount of tax benefit that is more than 50.0% likely to be realized upon ultimate settlement with the related tax authority. The following table summarizes the gross amount of the Company’s uncertain tax positions:

 

 

 

2025

 

Balance at beginning of the year

 

$

—

 

Increases related to prior year tax positions

 

 

334

 

Decreases related to prior year tax positions

 

 

—

 

Increases related to current year tax positions

 

 

289

 

Decreases related to lapse of statute of limitations

 

 

—

 

Balance at end of the year

 

$

623

 

Included in the balance of uncertain tax positions as of December 31, 2025, is $0.6 million that would affect the effective tax rate, if reversed, subject to changes in the Company’s valuation allowance.

The Company’s policy is to recognize interest and penalties related to income tax matters as a component of income tax expense. As of December 31, 2025, no interest and penalties have been recognized.

The Company is subject to audit by federal and state tax authorities in the ordinary course of business. The Company’s federal income tax returns remain subject to examination generally for the 2022 taxable year through the current taxable year, except for certain prior taxable years with net operating loss carry forwards that will remain subject to examination until the expiration of the statute of limitations for the taxable years of utilization of such net operating losses. The Company files tax returns in multiple US state jurisdictions which remain subject to examination for various years depending on such state jurisdiction. The Company is also subject to audit by tax authorities in Canada, Australia, Germany, Sweden, Belgium, and Denmark for which returns are subject to examination for various years, dependent on the jurisdiction.

The Organization for Economic Co-operation and Development (“OECD”) has introduced a framework to implement a global minimum corporate tax of 15%, referred to as Pillar Two. Many aspects of Pillar Two are effective beginning in calendar year 2024 and other aspects will be effective beginning in calendar year 2025. While it is uncertain whether the U.S. will adopt Pillar Two, certain countries in which the Company operates have adopted legislation and other countries are in the process of introducing legislation to implement Pillar Two. While the Company does not expect Pillar Two to have a material impact on its effective tax rate, the Company's analysis is ongoing as the OECD releases additional guidance and countries implement additional legislation.

The One Big Beautiful Bill Act ("OBBB Act") was enacted on July 4, 2025, in the United States. The OBBB Act includes several significant provisions, including re-establishing a 100% bonus depreciation deduction, re-establishing rules in calculating business interest expense limitations pursuant to Internal Revenue Code §163(j), changing the calculation of international tax inclusions, and removing the capitalization requirements for domestic research or experimental (R&E) expenditures paid or incurred in tax years beginning after December 31, 2024. Management has considered applicable tax impacts of the OBBB Act within the 2025 financial statements.
v3.25.4
Debt
 12 Months Ended
Dec. 31, 2025
Debt Disclosure [Abstract]  
Debt

13. DEBT

Debt consisted of the following:

 

 

 

December 31, 2025

 

 

December 31, 2024

 

Term loan facility

 

$

197,500

 

 

$

189,218

 

Revolving line of credit

 

 

84,663

 

 

 

25,191

 

Aircraft loan

 

 

8,125

 

 

 

9,272

 

Less deferred debt issuance costs

 

 

(1,993

)

 

 

(997

)

Total debt

 

$

288,295

 

 

$

222,684

 

Less current portion of long-term debt

 

 

(11,230

)

 

 

(17,866

)

Long-term debt, less current portion

 

$

277,065

 

 

$

204,818

 

Deferred Financing Costs—Costs relating to debt issuance have been deferred and are presented as discounted against the underlying debt instrument. These costs are amortized to interest expense over the terms of the underlying debt instruments. The amortization of deferred debt issuance cost to interest expense was $1.4 million, $0.7 million, and $0.5 million, for the years ended December 31, 2025, 2024 and 2023, respectively.

2025 Credit Facility—On February 26, 2025, the Company entered into an Amended and Restated Senior Secured Credit Agreement providing for a $500.0 million credit facility comprised of a $200.0 million term loan and a $300.0 million revolving line of credit (2025 Credit Facility). The revolving line of credit under the 2025 Credit Facility includes a $20.0 million sublimit for the issuances of letters of credit. Subject to certain exceptions, all amounts under the 2025 Credit Facility will become due on February 26, 2030. The Company has the option to borrow incremental term loans, or request an increase in aggregate commitments under the revolving line of credit up to an aggregate amount of $200.0 million, subject to the satisfaction of certain conditions.

The Company used proceeds from the 2025 Credit Facility to repay in full its prior senior secured credit facility originally entered into in 2021. The resulting write-off of the remaining unamortized debt issuance costs from the prior credit facility amounted to $0.9 million. Total loss on debt extinguishments is recorded in interest expense-net within the consolidated statements of operations for the year ended December 31, 2025.

The 2025 Credit Facility term loan must be repaid in quarterly installments and shall amortize at a rate of 1.25% per quarter beginning December 31, 2025 through December 31, 2029, with final payment and amortization on February 26, 2030.

The 2025 Credit Facility term loan and the revolving line of credit bear interest subject to the applicable spread based on the Company’s leverage ratio and SOFR as follows:

 

Pricing Tier

 

Consolidated
Leverage Ratio

 

Senior Credit Facilities
Benchmark Spread

 

 

Senior Credit Facilities
Base Rate Spread

 

 

Commitment
Fee

 

 

Letter of
Credit Fee

 

 

1

 

≥ 3.75x to 1.0

 

 

2.50

 

%

 

1.50

 

%

 

0.25

 

%

 

2.50

 

%

2

 

< 3.75x to 1.0 but ≥ 3.25 to 1.0

 

 

2.25

 

 

 

1.25

 

 

 

0.23

 

 

 

2.25

 

 

3

 

<3.25x to 1.0 but ≥ 2.50 to 1.0

 

 

2.00

 

 

 

1.00

 

 

 

0.20

 

 

 

2.00

 

 

4

 

<2.50x to 1.0 but ≥ 1.75 to 1.0

 

 

1.75

 

 

 

0.75

 

 

 

0.15

 

 

 

1.75

 

 

5

 

<1.75x to 1.0

 

 

1.50

 

 

 

0.50

 

 

0.15

 

 

 

1.50

 

 

The 2025 Credit Facility includes a number of covenants imposing certain restrictions on the Company’s business, including, among other things, restrictions on the Company’s ability, subject to certain exceptions and baskets, to incur indebtedness, incur liens on its assets, agree to any additional negative pledges, pay dividends or repurchase stock, limit the ability of its subsidiaries to pay dividends or distribute assets, make investments, enter into any transaction of merger or consolidation, liquidate, wind-up or dissolve, or convey any part of its business, assets or property, or acquire the business, property or assets of another person, enter into sale and leaseback transactions, enter into certain transactions with affiliates, engage in any material line of business substantially different from those engaged on the closing date, modify the terms of indebtedness subordinated to the loans incurred under the 2025 Credit Facility and modify the terms of its organizational documents. The 2025 Credit Facility permits certain restricted payments, including common stock repurchases, subject to a maximum pro-forma leverage ratio of 3.00 times, and minimum pro-forma fixed charge coverage ratio of 1.25 times and no event of default. The 2025 Credit Facility also includes financial covenants which require the Company to remain below a maximum total net leverage ratio of 4.00 times until the fiscal quarter ending March 31, 2026, stepping down to 3.75 times thereafter, and a minimum fixed charge coverage ratio of 1.25 times.

The Company deferred $2.2 million of debt issuance costs related to the 2025 Credit Facility in the first quarter of 2025. Quarterly installment repayments for the term loan under the 2025 Credit Facility commenced in the fourth quarter of 2025. For the year ended December 31, 2025 quarterly term loan installment repayments under the 2025 Credit Facility were $2.5 million. For the year ended December 31, 2024 quarterly term loan installment repayments under the prior senior secured credit facility were $15.0 million.

As of December 31, 2025 and December 31, 2024, the Company’s consolidated total leverage ratio (as defined in the applicable credit facility) was 2.5 times and 2.1 times, respectively, and the Company was in compliance with all covenants under the applicable credit facility.

The 2025 Credit Facility requires customary mandatory prepayments of the term loan and revolving line of credit and cash collateralization of letters of credit, subject to customary exceptions, including 100.0% of the proceeds of debt not permitted by the 2025 Credit Facility, 100.0% of the proceeds of certain dispositions, subject to customary reinvestment rights, where applicable, and 100.0% of insurance or condemnation proceeds, subject to customary reinvestment rights, where applicable. The 2025 Credit Facility also includes customary events of default and related acceleration and termination rights.

The weighted average interest rate for the year ended December 31, 2025, before giving effect to the impact of the interest rate swaps, was 6.1% and after giving effect to the impact of the interest rate swaps, was 5.5%. The weighted average interest rate for the year ended December 31, 2024, before giving effect to the impact of the interest rate swaps, was 7.2% and after giving effect to the impact of the interest rate swaps, was 5.8%.

The Company’s obligations under the 2025 Credit Facility are guaranteed by certain of the Company’s existing and future direct and indirect subsidiaries, and such obligations are secured by substantially all of the Company’s assets, including the capital stock or other equity interests in those subsidiaries.

As of December 31, 2025, the Company had the following interest rate swap agreements in place:

 

Effective date

 

Expiration date

 

Notional amount

 

 

Fixed rate

 

Floating rate

5/30/2023

 

4/27/2026

 

$

70,000,000

 

 

3.880%

 

USD-SOFR

6/5/2024

 

6/27/2027

 

$

80,000,000

 

 

3.270%

 

USD-SOFR

4/1/2025

 

4/27/2028

 

$

50,000,000

 

 

3.625%

 

USD-SOFR

Loan and Aircraft Security Agreement—On May 18, 2023, the Company entered into a Loan and Aircraft Security Agreement to finance $10.9 million of the purchase a new aircraft (Aircraft Loan). The Aircraft Loan must be repaid in 60 monthly consecutive installments and all outstanding amounts will become due on May 18, 2028. The Aircraft Loan bears interest subject to 1-Month Term SOFR and a coupon of 1.86%. The entire principal balance may be prepaid in full subject to a 3.0%, 2.0% and 1.0% prepayment fee if paid prior to the first, second and third anniversary of the loan, respectively. The aircraft serves as collateral security for the Aircraft Loan.

The following is a schedule of the aggregate annual maturities of long-term debt (excluding current portion) presented on the consolidated statement of financial position as of December 31, 2025, before deferred debt issuance cost of $2.0 million, based on the terms of the 2025 Credit Facility and the Aircraft Loan:

 

 

 

2025 Credit Facility

 

 

 

 

 

 

 

Term Loan

 

Revolving Line of Credit

 

Aircraft Loan

 

Total

 

2027

 

$

10,000

 

$

—

 

$

1,318

 

$

11,318

 

2028

 

 

10,000

 

 

—

 

 

577

 

 

10,577

 

2029

 

 

10,000

 

 

—

 

 

5,000

 

 

15,000

 

2030

 

 

157,500

 

 

84,663

 

 

—

 

 

242,163

 

Total

 

$

187,500

 

$

84,663

 

$

6,895

 

$

279,058

 
v3.25.4
Fair Value of Financial Instruments
 12 Months Ended
Dec. 31, 2025
Fair Value Disclosures [Abstract]  
Fair Value of Financial Instruments

14. FAIR VALUE OF FINANCIAL INSTRUMENTS

The following financial assets and liabilities are measured at fair value on a recurring basis using significant unobservable inputs (Level 3):

 

 

December 31, 2025

 

 

December 31, 2024

 

Interest rate swap(1)

$

—

 

 

$

1,544

 

Total Assets

$

—

 

 

$

1,544

 

 

 

 

 

 

 

Business acquisitions contingent consideration, current

$

14,883

 

 

$

26,872

 

Business acquisitions contingent consideration, long-term

 

2,755

 

 

 

6,255

 

Conversion option

 

—

 

 

 

20,224

 

Interest rate swap (1)

 

429

 

 

 

—

 

Total Liabilities

$

18,067

 

 

$

53,351

 

 

(1) Included in other non-current liabilities and other assets in the consolidated statement of financial position as of December 31, 2025 and consolidated statement of financial position as of December 31, 2024, respectively.

The estimated fair value amounts shown above are not necessarily indicative of the amounts that the Company would realize upon disposition, nor do they indicate the Company’s intent or ability to dispose of the financial instrument.

The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis:

 

 

Interest Rate Swap

 

 

Total Assets

 

 

Business Acquisitions Contingent Consideration, Current

 

 

Business Acquisitions Contingent Consideration, Long-term

 

 

Conversion Option

 

 

Interest Rate Swap

 

 

Total Liabilities

 

Balance as of December 31, 2022

$

6,046

 

 

$

6,046

 

 

$

3,801

 

 

$

4,454

 

 

$

25,731

 

 

$

—

 

 

$

33,986

 

Acquisitions

 

—

 

 

 

—

 

 

 

397

 

 

 

730

 

 

 

—

 

 

 

—

 

 

 

1,127

 

Changes in fair value included in earnings

 

(2,585

)

 

 

(2,585

)

 

 

(174

)

 

 

(22

)

 

 

(6,714

)

 

 

—

 

 

 

(6,910

)

Payment of contingent consideration payable

 

—

 

 

 

—

 

 

 

(3,146

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(3,146

)

Reclass of long term to short term contingent liabilities

 

—

 

 

 

—

 

 

 

2,714

 

 

 

(2,714

)

 

 

—

 

 

 

—

 

 

 

—

 

Balance as of December 31, 2023

$

3,461

 

 

$

3,461

 

 

$

3,592

 

 

$

2,448

 

 

$

19,017

 

 

$

—

 

 

$

25,057

 

Acquisitions

 

—

 

 

 

—

 

 

 

5,104

 

 

 

22,899

 

 

 

—

 

 

 

—

 

 

 

28,003

 

Changes in fair value included in earnings

 

(1,917

)

 

 

(1,917

)

 

 

1,879

 

 

 

(1,345

)

 

 

1,207

 

 

 

—

 

 

 

1,741

 

Payment of contingent consideration payable

 

—

 

 

 

—

 

 

 

(1,450

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(1,450

)

Reclass of long term to short term contingent liabilities

 

—

 

 

 

—

 

 

 

17,747

 

 

 

(17,747

)

 

 

—

 

 

 

—

 

 

 

—

 

Balance as of December 31, 2024

$

1,544

 

 

$

1,544

 

 

$

26,872

 

 

$

6,255

 

 

$

20,224

 

 

$

—

 

 

$

53,351

 

Changes in fair value included in earnings

 

(1,544

)

 

 

(1,544

)

 

 

(180

)

 

 

1,080

 

 

 

(20,224

)

 

 

429

 

 

 

(18,895

)

Payment of contingent consideration payable

 

—

 

 

 

—

 

 

 

(17,937

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(17,937

)

Reclass of long term to short term contingent liabilities

 

—

 

 

 

—

 

 

 

4,580

 

 

 

(4,580

)

 

 

—

 

 

 

—

 

 

 

—

 

Measurement period adjustment

 

—

 

 

 

—

 

 

 

1,548

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

1,548

 

Balance as of December 31, 2025

$

—

 

 

$

—

 

 

$

14,883

 

 

$

2,755

 

 

$

—

 

 

$

429

 

 

$

18,067

 

Quantitative Information about Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3):

Interest Rate Swaps—The interest rate swaps fair value is estimated based on a mid-market price for the swap as of the close of business of the reporting period. The fair value is prepared by discounting future cash flows of the swaps to arrive at a current value of the swap. Forward curves and volatility levels inputs are determined on the basis of observable market inputs when available and on the basis of estimates when observable market inputs are not available. The Company does not apply hedge accounting but instead recognizes the instrument at fair value on the consolidated statement of financial position within other assets, with changes in fair value recognized as other income (expense) in each reporting period.

Business Acquisitions Contingent Consideration—The fair values of the contingent consideration payables resulted from acquisitions were calculated based on expected target achievement amounts, which are measured quarterly and then subsequently adjusted to actuals at the target measurement date. Prior to the second quarter of 2023, the fair value of the contingent consideration payable associated with the acquisition of Sensible was determined using a Monte Carlo simulation of earnings in a risk-neutral Geometric Brownian Motion framework. As of December 31, 2023, the Sensible earnout was expected to be achieved in full and therefore, the entire payable has been recorded. The method used to price these liabilities is considered level 3 due to the subjective nature of the unobservable inputs used to determine the fair value. The input is the expected achievement of earn-out thresholds.

Conversion Option—The fair value of the conversion option associated with the issuance of the Convertible and Redeemable Series A-2 Preferred Stock (Note 16) was estimated using a “with-and-without” method. The “with-and-without” methodology considers the value of the security on an as-is basis and then without the embedded conversion premium. The difference between the two scenarios is the implied fair value of the embedded derivative. The unobservable input is the

required rate of return on the Series A-2 Preferred Stock. The considerable quantifiable inputs in the valuation relate to the timing of conversions or redemptions.
v3.25.4
Commitments and Contingencies
 12 Months Ended
Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies

15. COMMITMENTS AND CONTINGENCIES

Leases—The Company leases office facilities over various terms expiring through 2040. Certain of these operating leases contain rent escalation clauses. The Company also has office equipment leases that expire through 2045 (Note 7 and 13).

Other Commitments—The Company has commitments under the 2025 Credit Facility, its Aircraft Loan, its equipment line of credit and its lease obligations (Note 7 and 13). The Company has entered into a purchase contract to purchase a total of $4.9 million of equipment over the course of 7 years that commenced on July 1, 2024, subject to a minimum spending requirement per year, measured from the commencement date and each anniversary thereof. The minimum spend requirement is $0.2 million, $0.4 million, and $0.9 million for 2025, 2026, and 2027, respectively, with the remainder subject to mutual agreement after the first three years. Amounts purchased for the year ended December 31, 2025 were $0.7 million.

Contingencies—The Company is subject to purchase price contingencies related to earn-outs associated with certain acquisitions (Note 8 and 14).

Legal—In the normal course of business, the Company is at times subject to pending and threatened legal actions. In management’s opinion, any potential loss resulting from the resolution of these matters is not expected to have a material effect on the consolidated results of operations, financial position or cash flows of the Company.
v3.25.4
Convertible and Redeemable Series A-2 Preferred Stock
 12 Months Ended
Dec. 31, 2025
Temporary Equity Disclosure [Abstract]  
Convertible and Redeemable Series A-2 Preferred Stock

16. CONVERTIBLE AND REDEEMABLE SERIES A-2 PREFERRED STOCK

On April 13, 2020, the Company entered into an agreement to issue 17,500 shares of the Convertible and Redeemable Series A-2 Preferred Stock with a par value of $0.0001 per share and a detachable warrant to purchase shares of the Company’s common stock with a 10-year life, in exchange for gross proceeds of $175.0 million, net of $1.3 million debt issuance costs. The Convertible and Redeemable Series A-2 Preferred Stock warrants were exercised in full on July 30, 2020. Dividends on the Convertible and Redeemable Series A-2 Preferred Stock accrued through the date of the Company’s initial public offering on July 23, 2020, and were added to the principal balance outstanding as of that date. All dividends on the Convertible and Redeemable Series A-2 Preferred Stock after that date have been paid in cash. The Company paid dividends of $4.2 million, $11.1 million, and $16.4 million during the years ended December 31, 2025, 2024, and 2023 respectively.

The Convertible and Redeemable Series A-2 Preferred Stock terms included the following: (i) no mandatory redemption, (ii) no stated value cash repayment obligation other than in the event of certain defined liquidation events, (iii) only redeemable at the Company’s option, (iv) convertible into common stock beginning in April 2024 at a 15.0% discount to the common stock market price (with a limit of $60.0 million in stated value of Convertible and Redeemable Series A-2 Preferred Stock eligible to be converted in any 60-day period prior to the seventh anniversary of issuance and the amount of stated value of the Convertible and Redeemable Series A-2 Preferred Stock eligible for conversion limited to $60.0 million during year 5 and $120.0 million (which includes the aggregate amount of the stated value of the Convertible and Redeemable Series A-2 Preferred Stock and any accrued but unpaid dividends added to such stated value of any shares of Convertible and Redeemable Series A-2 Preferred Stock converted in year 5) during year 6), (v) 9.0% dividend rate per year with required quarterly cash payments, (vi) in an event of noncompliance, the dividend rate shall increase to 12.0% per annum for the first 90-day period from and including the date the noncompliance event occurred, and thereafter shall increase to 14.0% per annum, (vii) debt incurrence test ratio of 4.5 times, and (viii) minimum repayment amount of $25.0 million.

The Company could, at its option on any one or more dates, redeem all or a minimum portion (the lesser of (i) $25.0 million in aggregate stated value of the Convertible and Redeemable Series A-2 Preferred Stock and (ii) all of the Convertible and Redeemable Series A-2 Preferred Stock then outstanding) of the outstanding Convertible and Redeemable Series A-2 Preferred Stock in cash. In January 2024, the Company redeemed $60.0 million in aggregate stated value of the Convertible and Redeemable Series A-2 Preferred Stock in cash. The Company redeemed $60.0 million and $62.2 million in aggregate stated value of the outstanding Series A-2 Preferred Stock on April 1, 2025 and July 1, 2025, respectively. The Company funded each 2025 redemption with cash on hand and borrowings under the 2025 Credit Facility. Following the July 2025 redemption, no A-2 Preferred Shares remained outstanding. Both 2025 redemptions were reflected in the Company's Consolidated Statements of Convertible and Redeemable Series A-2 Preferred Stock and Stockholders’ Equity and resulted in a reduction of temporary equity. The impact of the redemptions is also reflected in the calculation of earnings per share for the year ended December 31, 2025.

The Convertible and Redeemable Series A-2 Preferred Stock did not meet the definition of a liability pursuant to “ASC 480- Distinguishing Liabilities from Equity.” However, as (i) the instrument was redeemable upon a change of control as defined in the certificate of designations governing the terms of the Convertible and Redeemable Series A-2 Preferred Stock, and (ii) the Company could not have asserted it would have sufficient authorized and unissued shares of common stock to settle all future conversion requests due to the variable conversion terms, the instrument was redeemable upon the occurrence of events that were not solely within the control of the Company, and therefore the Company classified the Convertible and Redeemable Series A-2 Preferred Stock as mezzanine equity prior to the July 2025 redemption of the remaining outstanding shares of A-2 Preferred Stock.

The Convertible and Redeemable Series A-2 Preferred Stock contained a conversion option of the preferred shares to shares of common stock beginning in April 2024. As of December 31, 2025 and 2024, this conversion embedded feature had a net fair value of $0.0 million and $20.2 million, respectively. The change in net fair value of $(20.2) million, $1.2 million and $6.7 million for the years ended December 31, 2025, 2024 and 2023, respectively, was recorded to other (income) expense.
v3.25.4
Stockholders' Equity
 12 Months Ended
Dec. 31, 2025
Equity [Abstract]  
Stockholders' Equity

17. STOCKHOLDERS’ EQUITY

Authorized Capital Stock—The Company was authorized to issue 190,000,000 shares of common stock, with a par value of $0.000004 per share as of December 31, 2025 and 2024.

Follow-on Offering—On April 22, 2024, the Company issued an aggregate of 3,450,000 shares of common stock in an underwritten public offering, inclusive of the shares of common stock issued in connection with the underwriters exercise in full of their option to purchase additional shares of common stock. The Company sold the shares to the underwriters at the public offering price of $37.15 per share, less underwriting discounts and commissions of $1.67175 per share, resulting in net proceeds to the Company after deducting underwriting discounts and commissions and estimated offering expenses of $121.8 million.

Stock Repurchase Program—On May 7, 2025, the Company announced that its Board of Directors has approved a stock repurchase program of up to $40.0 million. The repurchase program does not have a set expiration date. The Company did not make any repurchases under the program through December 31, 2025.

Employee Equity Incentive Plans—The Company has two plans under which stock-based awards have been issued: (i) the Montrose Amended and Restated 2017 Stock Incentive Plan (2017 Plan) and (ii) the Montrose Amended & Restated 2013 Stock Option Plan (2013 Plan) (collectively, the Plans).

As of December 31, 2025, there was $46.4 million of total unrecognized stock compensation expense related to unvested options and restricted stock granted under the Plans. Such unrecognized expense is expected to be recognized over a weighted-average 1.7 year period. The following number of shares were authorized to be issued and available for grant as of:

 

 

December 31, 2025

 

 

2017 Plan

 

 

2013 Plan

 

 

Total

 

Shares authorized to be issued

 

8,914,149

 

 

 

2,032,719

 

 

 

10,946,868

 

Shares available for grant(1)

 

2,359,812

 

 

 

—

 

 

 

2,359,812

 

 

 

 

 

 

 

 

 

 

 

December 31, 2024

 

 

2017 Plan

 

 

2013 Plan

 

 

Total

 

Shares authorized to be issued

 

7,538,276

 

 

 

2,036,219

 

 

 

9,574,495

 

Shares available for grant(1)

 

1,683,352

 

 

 

—

 

 

 

1,683,352

 

 

 

 

 

 

 

 

 

 

 

December 31, 2023

 

 

2017 Plan

 

 

2013 Plan

 

 

Total

 

Shares authorized to be issued

 

6,330,713

 

 

 

2,036,219

 

 

 

8,366,932

 

Shares available for grant(1)

 

662,662

 

 

 

—

 

 

 

662,662

 

 

(1) In January 2025, January 2024 and January 2023 the Board of Directors ratified the addition of 1,372,373, 1,207,563 and 1,189,801 shares of common stock, respectively, to the number of shares available for issuance under the 2017 Plan pursuant to the annual increase provision of such plan. Unless the Board of Directors determines otherwise, additional annual increases will be effective on each January 1, through January 1, 2027. The 2017 Plan permits the company to settle awards, if and when vested, in cash at its discretion. Pursuant to the terms of the 2017 Plan, the number of shares authorized for issuance thereunder will only be reduced with respect to shares of common stock actually issued upon exercise or settlement of an award. Shares of common stock subject to awards that have been canceled, expired, forfeited or otherwise not issued under an award and shares of common stock subject to awards settled in cash do not

count as shares of common stock issued under the 2017 Plan. Shares available for grant as of December 31, 2023 excluded awards of stock appreciation rights approved in December 2021 that were subject to vesting based on the achievement of certain market conditions, which had not yet been achieved when these awards were cancelled, effective as of December 31, 2024. See “Stock Appreciation Rights” below for additional information on stock appreciation rights.

Total stock compensation expense for the Plans was as follows:

 

 

Year Ended December 31, 2025

 

 

Options

 

 

RSUs

 

 

SARs

 

 

Total

 

Cost of revenue

$

729

 

 

$

4,629

 

 

$

—

 

 

$

5,358

 

Selling, general and administrative expense

 

875

 

 

 

36,483

 

 

 

—

 

 

 

37,358

 

Total

$

1,604

 

 

$

41,112

 

 

$

—

 

 

$

42,716

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Year Ended December 31, 2024

 

 

Options

 

 

RSUs

 

 

SARs

 

 

Total

 

Cost of revenue

$

1,223

 

 

$

3,578

 

 

$

—

 

 

$

4,801

 

Selling, general and administrative expense

 

2,571

 

 

 

30,088

 

 

 

27,205

 

 

 

59,864

 

Total

$

3,794

 

 

$

33,666

 

 

$

27,205

 

 

$

64,665

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Year Ended December 31, 2023

 

 

Options

 

 

RSUs

 

 

SARs

 

 

Total

 

Cost of revenue

$

1,685

 

 

$

1,661

 

 

$

—

 

 

$

3,346

 

Selling, general and administrative expense

 

4,885

 

 

 

29,851

 

 

 

9,185

 

 

 

43,921

 

Total

$

6,570

 

 

$

31,512

 

 

$

9,185

 

 

$

47,267

 

Montrose Amended & Restated 2017 Stock Incentive Plan

Restricted Stock Awards and Restricted Stock Units—The Company issues restricted stock awards (RSAs) to certain 2017 Plan participants as Director’s compensation. There were 46,899, 23,961, and 17,346 RSAs granted during the years ended December 31, 2025, 2024 and 2023 respectively. These RSAs vest one year from the date of grant, or, in each case, in full upon a change in control, subject to the participant’s continued service as a Director throughout such date, or upon retirement. Members of the Board of Directors that receive stock-based compensation are treated as employees for accounting purposes.

During 2023 the Board of Directors approved the grant of RSUs under certain supplemental incentive plans (SI Plans). There were 0, 0, and 370,349 RSUs issued under these SI Plans during the years ended December 31, 2025, 2024 and 2023, respectively. There were 237,634 RSUs issued during 2023 that vested 1/3 on the date of grant, 1/3 on the one-year anniversary of the grant, and 1/3 on the two-year anniversary of the grant, subject to continued service through each such date. The remaining RSUs vest annually over a 4-year period from the date of grant, subject to continued service through each such date.

During 2021, the Board of Directors approved the grant of 1,671,391 restricted stock units (RSUs) to certain executives and selected employees of the Company under the 2017 Plan. These RSUs represent the right to receive one share of the Company’s common stock upon vesting. These incentives were designed to (i) retain selected employees of the Company for a minimum of 5 years, (ii) reward selected employees for the Company’s significant outperformance and stockholder value creation in 2021, and (iii) provide incentives to selected employees of the Company to accelerate value creation for stockholders and other stakeholders over the next five-year period. With respect to 1,355,182 RSUs, 50.0% vested on the 4th anniversary and 50% will vest on the 5th anniversary of the date of grant, subject to continued service through each such date. With respect to the remaining 316,209 RSUs (The Performance-Vested RSUs), 50.0% vested on the 4th anniversary and 50% will vest on the 5th anniversary of the date of grant, subject to continued service through each such date.

During 2021, the Board of Directors approved and reserved for future issuance an aggregate of 135,517 RSUs (Future RSU Pool) to be granted under the 2017 Plan to certain of its executives and selected employees. Final determination and allocation of the awards under the Future RSU Pool may be determined on or before December 16, 2026 based on individual performance and continued service through such date. Any RSUs granted under the Future RSU Pool will vest on December 16, 2026, subject to continued service through such date.

RSA and RSU activity was as follows:

 

 

Year Ended December 31,

 

 

2025

 

 

2024

 

 

2023

 

 

Shares

 

 

Weighted-Average Grant Date Fair Value

 

 

Shares

 

 

Weighted-Average Grant Date Fair Value

 

 

Shares

 

 

Weighted-Average Grant Date Fair Value

 

Beginning outstanding shares

 

2,617,059

 

 

 

 

 

 

2,468,722

 

 

 

 

 

 

1,777,715

 

 

 

 

Granted

 

1,399,351

 

 

$

18.27

 

 

 

359,749

 

 

$

39.75

 

 

 

793,133

 

 

$

34.33

 

Forfeited/ cancelled

 

(166,158

)

 

$

27.76

 

 

 

(56,921

)

 

$

37.32

 

 

 

(11,311

)

 

$

32.13

 

Vested(1)

 

(1,525,848

)

 

$

49.25

 

 

 

(154,491

)

 

$

36.82

 

 

 

(90,815

)

 

$

36.77

 

Ending outstanding shares

 

2,324,404

 

 

 

 

 

 

2,617,059

 

 

 

 

 

 

2,468,722

 

 

 

 

 

(1) The 2025 vested shares amount includes 406,655 shares withheld related to net share settlement of equity awards.

There were an aggregate of 2,324,404, 3,148,847, and 2,846,019, shares underlying outstanding RSA and RSU awards as of December 31, 2025, 2024, and 2023, respectively.

Stock Appreciation Rights— During the year ended December 31, 2021, the Board of Directors approved the grant of 3,000,000 units of stock appreciation rights (SARs) to certain executives and selected employees under the 2017 Plan. These SARs represented the right to receive, upon exercise, a payment equal to the excess of (a) the fair market value of one share of the Company’s common stock, over (b) an exercise price of $66.79, payable, at the Company’s election, in cash or shares of common stock. These SARs were scheduled to vest on the 5th anniversary of the date of grant based on achievement of performance hurdles over a five year period, subject to continued service on the vesting date.

The fair value of these SARs at the grant date was $46.0 million, which was amortized on a straight-line basis over a five-year period.

Effective December 31, 2024, the Board of Directors approved the cancellation (SAR Cancellation) of the outstanding and unvested SARs previously granted on December 16, 2021, to the Company’s named executive officers, as well as certain other executives, and the applicable individuals each agreed to such SAR Cancellation. The SAR Cancellation was voluntary on the part of the named executive officers and other holders and was not in exchange for any other equity or cash-based compensation awards or payments. None of the market conditions had been achieved as of the date of cancellation. Upon cancellation, the remaining unamortized value of the SARs of $18.0 million was expensed within selling, general, and administrative expense.

Options—Options issued to all optionees under the 2017 Plan vest over 4-years from the date of issuance (or earlier vesting start date, as determined by the Board of Directors) as follows: one half on the second anniversary of date of grant and the remaining half on the fourth anniversary of the date of grant, with the exception of certain annual grants to certain executive officers, which vest annually over a 3-year and 1-year period. The following summarizes the options activity of the 2017 Plan for the years ended December 31, 2025, 2024 and 2023:

 

 

Options to Purchase Common Stock

 

 

Weighted-Average Exercise Price per Share

 

 

Weighted-Average Grant Date Fair Value per Share

 

 

Weighted-Average Remaining Contract Life (in Years)

 

 

Aggregate Intrinsic Value of In-The-Money Options

 

Outstanding as of December 31, 2022

 

2,579,566

 

 

$

31.00

 

 

$

15.00

 

 

 

7.8

 

 

$

37,295

 

Granted

 

253,980

 

 

 

32.41

 

 

 

13.98

 

 

 

—

 

 

 

—

 

Forfeited/ cancelled

 

(134,170

)

 

 

36.01

 

 

 

—

 

 

 

—

 

 

 

—

 

Expired

 

(6,450

)

 

 

32.03

 

 

 

—

 

 

 

—

 

 

 

—

 

Exercised

 

(176,654

)

 

 

24.12

 

 

 

—

 

 

 

—

 

 

 

3,726

 

Outstanding as of December 31, 2023

 

2,516,272

 

 

$

30.92

 

 

$

15.95

 

 

 

7.0

 

 

$

13,825

 

Forfeited/ cancelled

 

(78,130

)

 

 

38.57

 

 

 

—

 

 

 

—

 

 

 

—

 

Expired

 

(37,825

)

 

 

41.90

 

 

 

—

 

 

 

—

 

 

 

—

 

Exercised

 

(55,110

)

 

 

25.48

 

 

 

—

 

 

 

—

 

 

 

776

 

Outstanding as of December 31, 2024

 

2,345,207

 

 

$

30.62

 

 

$

16.32

 

 

 

6.0

 

 

$

776

 

Forfeited/ cancelled

 

(55,313

)

 

 

40.81

 

 

 

—

 

 

 

—

 

 

 

—

 

Expired

 

(71,812

)

 

 

37.12

 

 

 

—

 

 

 

—

 

 

 

—

 

Exercised

 

(24,554

)

 

 

14.88

 

 

 

—

 

 

 

—

 

 

 

266

 

Outstanding as of December 31, 2025

 

2,193,528

 

 

$

30.33

 

 

$

16.32

 

 

 

4.9

 

 

$

6,109

 

Exercisable as of December 31, 2025

 

1,992,545

 

 

$

29.41

 

 

 

 

 

 

4.8

 

 

$

6,109

 

The following weighted-average assumptions were used in the Black-Scholes option-pricing model calculation for 2023. There were no stock options granted in 2025 and 2024.

 

 

December 31, 2023

 

Common stock value (per share)

$

32.41

 

Expected volatility

 

33.55

%

Risk-free interest rate

 

3.77

%

Expected life (years)

 

7.00

 

Forfeiture rate

None

 

Dividend rate

None

 

 

Montrose Amended & Restated 2013 Stock Option Plan—The following summarizes the activity of the 2013 Plan for the years ended December 31, 2025, 2024 and 2023:

 

 

Options to Purchase Common Stock

 

 

Weighted-Average Exercise Price per Share

 

 

Weighted-Average Grant Date Fair Value per Share

 

 

Weighted-Average Remaining Contract Life (in Years)

 

 

Aggregate Intrinsic Value of In-The-Money Options

 

Outstanding as of December 31, 2022

 

855,695

 

 

$

6.00

 

 

$

2.10

 

 

 

3.3

 

 

$

32,478

 

Expired

 

(800

)

 

 

6.03

 

 

 

—

 

 

 

—

 

 

 

—

 

Exercised

 

(62,704

)

 

 

6.82

 

 

 

—

 

 

 

—

 

 

 

1,950

 

Outstanding as of December 31, 2023

 

792,191

 

 

$

6.40

 

 

$

2.16

 

 

 

2.4

 

 

$

20,380

 

Exercised

 

(111,302

)

 

 

5.87

 

 

 

—

 

 

 

—

 

 

 

3,042

 

Outstanding as of December 31, 2024

 

680,889

 

 

$

6.49

 

 

$

2.51

 

 

 

1.5

 

 

$

8,211

 

Expired

 

(3,500

)

 

 

6.03

 

 

 

—

 

 

 

—

 

 

 

—

 

Exercised

 

(109,562

)

 

 

6.40

 

 

 

—

 

 

 

—

 

 

 

1,991

 

Outstanding as of December 31, 2025

 

567,827

 

 

$

6.51

 

 

$

2.51

 

 

 

0.5

 

 

$

10,401

 

Exercisable as of December 31, 2025

 

567,827

 

 

$

6.51

 

 

 

 

 

 

0.5

 

 

$

10,401

 

Total shares outstanding from exercised options were 1,850,316 shares, 1,716,200 shares and 1,549,788 shares as of December 31, 2025, 2024 and 2023.

Common Stock Reserved for Future Issuances—The Company has reserved certain stock of its authorized but unissued common stock for possible future issuance in connection with the following:

 

 

December 31,

 

 

2025

 

 

2024

 

 

2023

 

Montrose 2013 Stock Incentive Plan

 

567,827

 

 

 

680,889

 

 

 

792,191

 

Montrose 2017 Stock Incentive Plan(1)

 

6,877,744

 

 

 

6,645,618

 

 

 

8,647,656

 

 

7,445,571

 

 

 

7,326,507

 

 

 

9,439,847

 

 

(1) In January 2025, January 2024 and January 2023 the Board of Directors ratified the addition of 1,372,373, 1,207,563 and 1,189,801 shares of common stock, respectively, to the number of shares available for issuance under the 2017 Plan pursuant to the annual increase provision of such plan. Unless the Board of Directors determines otherwise, additional annual increases will be effective on each January 1, through January 1, 2027. The 2017 Plan permits the company to settle awards, if and when vested, in cash at its discretion. Pursuant to the terms of the 2017 Plan, the number of shares authorized for issuance thereunder will only be reduced with respect to shares of common stock actually issued upon exercise or settlement of an award. Shares of common stock subject to awards that have been canceled, expired, forfeited or otherwise not issued under an award and shares of common stock subject to awards settled in cash do not count as shares of common stock issued under the 2017 Plan. Shares reserved for future issuance as of December 31, 2023 includes awards of SARs approved in December 2021 that were subject to vesting based on the achievement of certain market conditions, which had not yet been achieved when these awards were cancelled, effective as of December 31, 2024. See “Stock Appreciation Rights” above for additional information on stock appreciation rights.
v3.25.4
Net Loss Per Share
 12 Months Ended
Dec. 31, 2025
Earnings Per Share [Abstract]  
Net Loss Per Share

18. NET LOSS PER SHARE

Basic net loss per share is computed by dividing net loss attributable to common stockholders by the weighted average number of common shares outstanding during each period. The Convertible and Redeemable Series A-2 Preferred Stock was considered a participating security during the applicable period. Net losses were not allocated to the Convertible and Redeemable Series A-2 stockholders, as they were not contractually obligated to share in the Company’s losses.

Diluted net loss per share is computed by dividing net loss attributable to common stockholders by the weighted average number of common and dilutive common equivalent shares outstanding for the period using the treasury-stock method or the as-converted method. Potentially dilutive shares are comprised of RSAs, RSUs, SARs, Series A-2 Preferred Stock, and shares of common stock underlying stock options outstanding under the Plans. During the years ended December 31, 2025, 2024 and 2023, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss attributable to common stockholders and potentially dilutive shares being anti-dilutive.

The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company:

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

Net loss

 

$

(843

)

 

$

(62,314

)

 

$

(30,859

)

Convertible and Redeemable Series A-2 Preferred Stock dividend

 

 

(4,150

)

 

 

(11,064

)

 

 

(16,400

)

Net loss attributable to common stockholders – basic and diluted

 

 

(4,993

)

 

 

(73,378

)

 

 

(47,259

)

Weighted-average number of shares of common stock outstanding – basic and diluted

 

 

35,120

 

 

 

33,061

 

 

 

30,058

 

Net loss per share attributable to common stockholders – basic and diluted

 

$

(0.14

)

 

$

(2.22

)

 

$

(1.57

)

The following common stock equivalents were excluded from the calculation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive for the years ended December 31:

 

 

 

December 31,

 

 

 

2025(1)

 

 

2024(1)

 

 

2023(1)

 

Stock options

 

 

2,959,850

 

 

 

3,026,096

 

 

 

3,308,463

 

Restricted stock

 

 

2,324,404

 

 

 

2,617,059

 

 

 

2,468,722

 

Series A-2 Preferred Stock

 

 

2,654,739

 

 

 

4,293,793

 

 

 

5,952,609

 

SARs(2)

 

 

—

 

 

 

—

 

 

 

3,000,000

 

 

(1)
Includes 2,116,319, 2,374,716 and 7,660,169 shares underlying equity awards that were out of the money as of December 31, 2025, 2024 and 2023, respectively.
(2)
Effective December 31, 2024, the Board of Directors approved the SAR Cancellation (Note 17).
v3.25.4
Segment Information and Geographic Location Information
 12 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Segment Information and Geographic Location Information

19. SEGMENT INFORMATION AND GEOGRAPHIC LOCATION INFORMATION

The Company has six operating units that aggregate into three reportable segments: Assessment, Permitting and Response, Measurement and Analysis, and Remediation and Reuse. These segments are monitored separately by management for performance against budget and prior year and are consistent with internal financial reporting. The Company’s operating segments are organized based upon primary services provided, the nature of the production process, types of customers, methods used to distribute the products, and the nature of the regulatory environment. Refer to Note 1 for description of each reportable segment.

Our Chief Executive Officer, who serves as the CODM, reviews Segment Adjusted EBITDA in the annual budget and forecasting process. The CODM considers budget-to-actual variances on a quarterly basis when making decisions about the allocation of Company resources depending on the needs of each segment and the availability of resources. Segment Adjusted EBITDA is the calculated Company’s Earnings before Interest, Tax, Depreciation and Amortization (EBITDA), adjusted to exclude certain transactions such as stock-based compensation, acquisition costs, and fair value changes in financial instruments, amongst others. The CODM does not review segment assets as a measure of segment performance.

Corporate and Other includes costs associated with general corporate overhead (including executive, legal, finance, safety, human resources, marketing and IT related costs) that are not directly related to supporting operations. Overhead costs that are directly related to supporting operations (such as insurance, software, licenses, shared services and payroll processing costs) are allocated to the operating segments on a basis that reasonably approximates an estimate of the use of these services, and are included in Segment Expenses in the table below.

Segment Revenues, Segment Expenses and Segment Adjusted EBITDA were as follows:

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

(in thousands)

 

Segment Revenues

 

 

Segment Expenses

 

 

Segment Adjusted EBITDA

 

 

Segment Revenues

 

 

Segment Expenses

 

 

Segment Adjusted EBITDA

 

 

Segment Revenues

 

 

Segment Expenses

 

 

Segment Adjusted EBITDA

 

Assessment, Permitting and Response

 

$

307,428

 

 

$

238,973

 

 

$

68,455

 

 

$

214,850

 

 

$

166,830

 

 

$

48,020

 

 

$

220,727

 

 

$

168,579

 

 

$

52,148

 

Measurement and Analysis(1)

 

 

245,860

 

 

 

181,509

 

 

 

64,351

 

 

 

224,366

 

 

 

173,845

 

 

 

50,521

 

 

 

197,095

 

 

 

159,878

 

 

 

37,217

 

Remediation and Reuse

 

 

277,250

 

 

 

240,972

 

 

 

36,278

 

 

 

257,179

 

 

 

218,840

 

 

 

38,339

 

 

 

206,386

 

 

 

179,299

 

 

 

27,087

 

Total Reportable Segments

 

$

830,538

 

 

 

 

 

$

169,084

 

 

$

696,395

 

 

 

 

 

$

136,880

 

 

$

624,208

 

 

 

 

 

$

116,452

 

 

(1)
Includes revenue of $8.8 million and Adjusted EBITDA of $2.1 million from the Discontinued Specialty Lab for the year ended December 31, 2023. The lab was discontinued in the year ended December 31, 2023.

Presented below is a reconciliation of the Company’s segment measure to income (loss) before expense from income taxes for the years ended December 31:

 

 

 

For the Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

Total Reportable Segments

 

$

169,084

 

 

$

136,880

 

 

$

116,452

 

Corporate and Other

 

 

(52,920

)

 

 

(41,092

)

 

 

(37,876

)

Interest expense, net

 

 

(19,567

)

 

 

(15,862

)

 

 

(7,793

)

Depreciation and amortization

 

 

(50,915

)

 

 

(52,762

)

 

 

(45,780

)

Stock-based compensation

 

 

(42,716

)

 

 

(64,665

)

 

 

(47,267

)

Acquisition costs(1)

 

 

(1,825

)

 

 

(7,827

)

 

 

(6,930

)

Fair value changes in financial instruments

 

 

18,251

 

 

 

(3,124

)

 

 

4,129

 

Fair value changes in business acquisition contingencies

 

 

(900

)

 

 

(534

)

 

 

(84

)

Expenses related to financing transactions

 

 

(163

)

 

 

(317

)

 

 

(35

)

Discontinued Specialty Lab(2)

 

 

—

 

 

 

(692

)

 

 

(6,112

)

Business line restructuring costs(3)

 

 

(2,633

)

 

 

(146

)

 

 

(9

)

Other losses or expenses(4)

 

 

(4,475

)

 

 

(4,177

)

 

 

(534

)

Income (loss) before expense from income taxes

 

$

11,221

 

 

$

(54,318

)

 

$

(31,839

)

 

(1)
Includes financial and tax diligence, consulting, legal, valuation, accounting, travel and acquisition-related incentives related to our acquisition and integration activity.
(2)
Amounts consist of operating losses before depreciation related to the Discontinued Specialty Lab.
(3)
Amounts consist of severance costs related to organizational restructuring of business lines within the Company's Assessment, Permitting and Response and Remediation and Reuse segments, including costs incurred to wind down its renewable energy business.
(4)
The year ended December 31, 2025 consists primarily of losses and costs associated with exiting operations in Europe, nonrecurring rebranding expenses, and third party expenses associated with the independent review and analysis of assertions in a short seller report regarding the Company. The year ended December 31, 2024 consists primarily of non-recurring costs to centralize certain back-office functions, lease abandonment costs, and third party expenses associated with the independent review and analysis of assertions in a short seller report regarding the Company. The year ended December 31, 2023 consists primarily of expenses related to an aircraft accident, net of insurance gain, as well as a gain on the surrender of a lease.

The following table presents revenues by geographic location:

 

 

 

For the Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

United States

 

$

678,382

 

 

$

550,323

 

 

$

539,578

 

Canada

 

 

120,762

 

 

 

115,918

 

 

 

72,608

 

Other international

 

 

31,394

 

 

 

30,154

 

 

 

12,022

 

Total revenue

 

$

830,538

 

 

$

696,395

 

 

$

624,208

 

 

The following table presents long-lived assets by geographic location:

 

 

 

For the Year Ended December 31,

 

 

 

2025

 

 

2024

 

United States

 

$

58,590

 

 

$

57,730

 

Canada

 

 

4,311

 

 

 

5,070

 

Other international

 

 

952

 

 

 

976

 

Total property and equipment—net

 

$

63,853

 

 

$

63,776

 
v3.25.4
Related-Party Transactions
 12 Months Ended
Dec. 31, 2025
Related Party Transactions [Abstract]  
Related-Party Transactions

20. RELATED-PARTY TRANSACTIONS

The Company did not have any material related party transactions during the years ended December 31, 2025, 2024 and 2023.
v3.25.4
Defined Contribution Plan
 12 Months Ended
Dec. 31, 2025
Retirement Benefits [Abstract]  
Defined Contribution Plan

21. DEFINED CONTRIBUTION PLAN

On January 1, 2014, the Company established the Montrose Environmental Group 401(k) Savings Plan (401(k) Savings Plan). As of December 31, 2025, 2024, and 2023, plan participants may defer up to 85.0% of their eligible wages for the year, up to the Internal Revenue Service dollar limit and catch-up contribution allowed by law. The Company provides employer matching contributions equal to 100% of the participant’s elective deferrals that do not exceed 3% of the participant’s compensation and 50% of the participant’s elective deferrals that exceed 3% but do not exceed 5% of the participant’s compensation. Employer contributions for years ended December 31, 2025, 2024, and 2023 were $10.4 million, $9.1 million and $7.9 million, respectively.
v3.25.4
Subsequent Events
 12 Months Ended
Dec. 31, 2025
Subsequent Events [Abstract]  
Subsequent Events

22. SUBSEQUENT EVENTS

On February 16, 2026, the Company entered into foreign currency forward contracts having a total notional amount of approximately $22.4 million. The purpose of these contracts was to hedge a portion of the Company's 2026 forecasted foreign exchange exposure to fluctuations in the AUD and CAD exchange rates relative to the U.S. dollar. The contracts mature monthly and expire in December 2026.
v3.25.4
Significant Accounting Policies (Policies)
 12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Basis of Presentation

Basis of Presentation—The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP). Intercompany balances and transactions are eliminated.
Use of Estimates

Use of Estimates—The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates inherent in the preparation of the accompanying consolidated financial statements include, but are not limited to, management’s forecasts of future cash flows used as a basis to assess recoverability of goodwill and long-lived assets, the allocation of purchase price to tangible and intangible assets, allowances for doubtful accounts, the estimated useful lives over which property and equipment is depreciated and intangible assets are amortized, subsequent measurement of goodwill, the fair value of contingent consideration payables, the fair value of embedded derivatives, equity-based compensation expense and deferred taxes. These estimates could materially differ from actual results.
Cash, Cash Equivalents and Restricted Cash

Cash, Cash Equivalents and Restricted Cash—The Company maintains its cash in bank deposit accounts, which at times may exceed federally insured limits. The Company considers cash deposits in banks as cash with original maturities at purchase of three months or less as cash equivalents.

Cash, long-term debt and financial instruments subject the Company to concentrations of credit risk. To minimize the risk of credit loss, these financial instruments are primarily held with large, reputable financial institutions. The Company has not experienced losses in such accounts and believes it is not exposed to any significant credit risk associated with these accounts.

Cash that is restricted as to withdrawal or use under the terms of certain contractual agreements is recorded in restricted cash in the Company’s consolidated statements of financial position. The Company's restricted cash balances were $0.2 million and $1.5 million as of December 31, 2025 and 2024, respectively.
Accounts Receivables-Net

Accounts Receivables-Net—Accounts receivable are presented in the consolidated statements of financial position, net of an allowance for doubtful accounts. The allowance for doubtful accounts is established at the origination of an account in accordance with Accounting Standard Update (ASU) 2016-13, Financial Instruments—Credit Losses (Topic 326). Accounting Standards Codification (ASC) 326 requires the Company to estimate the lifetime expected credit losses on such instruments and to record an allowance to offset the receivables.

Financial Instruments

Financial Instruments—The Financial Accounting Standards Board (FASB) ASC 820, Fair Value Measurements and Disclosures, defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. ASC 820 establishes a three-level fair value hierarchy that prioritizes the inputs and minimizes the use of unobservable inputs. The three levels of inputs used to measure fair values are as follows:

Level 1—Quoted prices in active markets for identical assets or liabilities.

Level 2—Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data.

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. The inputs to the determination of fair value are based upon the best information in the circumstances and may require significant management judgment or estimation.

The Company considers the carrying values of cash, cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued expenses to approximate fair value for these financial instruments due to the short maturities of these instruments. The Company’s interest rate swap, embedded derivatives, and any acquisition’s contingent consideration are carried at fair value and determined according to the fair value hierarchy above.

The Company’s variable rate borrowings under its Credit Facility (Note 13) is tied to market indices and, thus, approximate fair value. The estimated fair value of the long-term debt under the credit facility is based on borrowing rates currently available to the Company for loans with similar terms and remaining maturities.
Impairment of Long-Lived Assets

Impairment of Long-Lived Assets—Certain events or changes in circumstances may indicate that the recoverability of the carrying amount of long lived assets should be assessed. When such events or changes in circumstances are present, the Company estimates the future cash flows expected to result from the use of the asset (or asset group) and its eventual disposition. If the sum of the expected undiscounted future cash flows is less than the carrying amount, the Company recognizes an impairment based on the fair value of such assets.
Acquisitions

Acquisitions—The Company first assesses whether the acquisition represents a purchase of assets or a business. If the transaction is a business acquisition, the Company accounts for the acquisition using business combination accounting, which requires that assets acquired and liabilities assumed be recognized at fair value as of the acquisition date. The purchase price of acquisitions is allocated to the tangible and identifiable intangible assets acquired and liabilities assumed based on estimated fair values, and any excess purchase price over the identifiable assets acquired and liabilities assumed is recorded as goodwill. Goodwill represents the premium the Company pays over the fair value of the net tangible and intangible assets acquired. The Company may use independent valuation specialists to assist in determining the estimated fair values of assets acquired and liabilities assumed, which could require certain significant management assumptions and estimates. Transaction costs associated with acquisitions of businesses are expensed as they are incurred.
Business Acquisition Contingencies

Business Acquisition Contingencies—Some of the Company’s acquisition agreements include contingent consideration arrangements, which are generally based on the achievement of future performance thresholds. For each transaction, the Company estimates the fair value of contingent consideration payments as part of the initial purchase price and record the estimated fair value of contingent consideration as a liability. Subsequent changes in the fair value of contingent consideration are recognized as a gain or loss in the consolidated statements of operations. Payments of contingent consideration are reflected in financing activities in the consolidated statements of cash flows to the extent included as part of the initial purchase price, or in operating activities if the payment exceeds the amount included in the initial purchase price.
Goodwill

Goodwill—Goodwill is not amortized but instead qualitatively or quantitatively tested for impairment at least annually. Should an event or circumstances indicate that a reduction in fair value of the reporting unit may have occurred during the year, goodwill would also be tested at such occasion. The Company performs its goodwill test at the reporting unit level. If necessary, the goodwill quantitative impairment test is performed on October 1st every year.

The Company uses a two-step process to assess the realizability of goodwill. The first step (generally referred to as a "step 0" analysis) is a qualitative assessment that analyzes current economic indicators associated with a particular reporting unit. For example, the Company analyzes changes in economic, market and industry conditions, business strategy, cost factors, and financial performance, among others, to determine if there are indicators of a significant decline in the fair value of a particular reporting unit. If the qualitative assessment indicates a stable or improved fair value, no further testing is required. If a qualitative assessment indicates it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the Company will proceed to the quantitative second step (generally referred to as a "step 1" analysis).

Step 1 of the quantitative test requires comparison of the carrying value of each of the reporting units to the respective fair value, calculated based on weighted income and market-based approaches. If the carrying value of the reporting unit is less than the fair value, no impairment exists. Otherwise, the Company would recognize an impairment charge for the amount by which the carrying amount of a reporting unit exceeds its fair value up to the amount of goodwill allocated to that reporting unit.

The Company's annual assessment of goodwill has historically been completed as of the beginning of the fourth quarter each year. The Company performed its 2025 and 2024 annual assessments as of October 1 of each year and determined that no impairment existed as the estimated fair value of each of the Company's reporting units was in excess of its respective carrying value. Also, no triggering events or changes in circumstances occurred during the period October 1, 2025 through December 31, 2025 that warranted retesting goodwill for impairment.
Embedded Derivatives

Embedded Derivatives—Embedded derivatives that are required to be bifurcated from the underlying host instrument are accounted for and valued as a separate financial instrument. These embedded derivatives are bifurcated, accounted for at their estimated fair value, which is based on certain estimates and assumptions, and presented separately on the consolidated statements of financial position. Our valuation of embedded derivatives follows the With and Without method of the income approach, where the value of the derivative is derived by comparing projected cash flows with and without the embedded feature. The discount rate reflects the level of risk associated with these cash flows and is determined based on and evaluation of the Company’s credit risk and market required yields for comparable securities with similar credit risk. To derive a credit rating indication, the Company utilizes the Synthetic Credit Rating Model, and the recovery rate method is employed to establish the Company’s discount rate. Changes in fair value of the embedded derivatives are recognized as a component of other income/expense on the Company’s consolidated statements of operations (Note 16).

Foreign Currency

Foreign Currency—The Company historically has operations in the United States, Canada, Australia and Europe. In 2025, the Company exited all operations in Europe. The results of its non-U.S. dollar based functional currency operations are translated to U.S. dollars at the average exchange rates during the period. The Company’s assets and liabilities are translated using the exchange rate as of the date of the consolidated statement of financial position and equity is translated using historical rates. Adjustments resulting from the translation of the consolidated financial statements of the Company’s foreign functional currency subsidiaries into U.S. dollars are excluded from the determination of net income (loss) and instead are included in accumulated other comprehensive loss as a separate component of stockholders’ equity. Foreign exchange transaction gains and losses are included in selling, general and administrative expense on the consolidated statements of operations.
Accumulated Other Comprehensive Loss

Accumulated Other Comprehensive Loss—Accumulated other comprehensive loss, as presented on the consolidated statements of redeemable convertible and redeemable Series A-2 Preferred Stock and stockholders’ equity, consists of unrealized gains and losses on foreign currency translation. Comprehensive income (loss) is not included in the computation of income tax benefit.
Revenue Recognition

Revenue Recognition—Revenue is recognized in accordance with ASC Topic 606, Revenue from Contracts with Customers. The following is considered by the Company in the recognition of revenue under ASC 606:

The Company’s services are performed under two general types of contracts (i) fixed-price and (ii) time-and-materials. Under fixed-price contracts, customers pay an agreed-upon amount for a specified scope of work agreed to in advance of the project. Under time-and-materials contracts, customers pay for the hours worked and resources used based on agreed-upon rates. Certain of the Company’s time-and-materials contracts are subject to maximum contract amounts. The duration of the Company’s contracts ranges from less than one month to over a year, depending on the scope of services provided. Payment terms are agreed upon at the time of contract approval and are typically net 30. Costs to obtain and fulfill contracts associated with system sales are expensed as a cost of revenue when the Company has fulfilled its performance obligations.

The Company accounts for individual promises in contracts as separate performance obligations if the promises are distinct. The assessment requires judgment. The majority of the Company’s contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and is, therefore, not distinct. Certain contracts in the Company’s Measurement and Analysis segment have multiple performance obligations, most commonly due to the contracts providing for multiple laboratory tests which are individual performance obligations.

For the Measurement and Analysis contracts with multiple performance obligations, the Company allocates the transaction price to each performance obligation based on the relative standalone selling price of each performance obligation. The standalone selling price of each performance obligation is generally determined by the observable price of a service when sold separately.

Fixed fee contracts—On the majority of fixed fee contracts, the Company recognizes revenue, over time, using either the proportion of actual costs incurred to the total costs expected to complete the contract performance obligation (cost to cost method), or the time-elapsed basis. The Company determined that the cost to cost method best represents the transfer of services as the proportion closely depicts the efforts or inputs completed towards the satisfaction of a fixed fee contract performance obligation. Under the time-elapsed basis, the arrangement is considered a single performance obligation comprised of a series of distinct services that are substantially the same and that have the same pattern of transfer (i.e. distinct days of service). The Company applies a time-based measure of progress to the total transaction price, which results in ratable recognition over the term of the contract. For a portion of the Company’s laboratory service contracts, revenue is recognized as performance obligations are satisfied over time, with recognition reflecting a series of distinct services using the output method. The Company determined that this method best represents the transfer of services as the customer obtains equal benefit from the service throughout the service period.

There are inherent uncertainties in the estimation process for cost to cost contracts, as the estimation of total contract costs and estimates to complete is complex, subject to many variables, and requires judgment. It is possible that estimates of costs to complete a performance obligation will be revised in the near-term based on actual progress and costs incurred. These uncertainties primarily impact the Company’s contracts in the Remediation and Reuse segment.

Time-and-materials contracts—Time-and-materials contracts contain variable consideration. However, these arrangements qualify for the “Right to Invoice” practical expedient. Under this practical expedient, the Company recognized revenue, over time, in the amount to which the Company has a right to invoice. In addition, the Company is not required to estimate such variable consideration upon inception of the contract and reassess the estimate each reporting period. The Company determined that this method best represents the transfer of services as, upon billing, the Company had a right to consideration from a customer in an amount that directly corresponded with the value to the customer of the Company’s performance completed to date.
Segment Reporting

Segment Reporting—Operating segments are components of an enterprise for which discrete financial reporting information is available and evaluated regularly by the Chief Operating Decision Maker (CODM) in deciding how to allocate resources and in assessing performance. The Company has identified its Chief Executive Officer as the CODM. The CODM views the Company’s operations and manages the businesses as three operating segments, which are also the Company’s reportable segments: (i) Assessment, Permitting and Response, (ii) Measurement and Analysis, and (iii) Remediation and Reuse.
Stock-Based Compensation

Stock-Based Compensation—The Company sponsors stock incentive plans that allow for issuance of employee stock options, restricted stock awards, restricted stock units and stock appreciation rights awards.

There are certain awards that were issued to non-employees in exchange for their services and are accounted for under ASC 505, Equity-Based Payments to Non-Employees. ASC 505 requires that the fair value of the equity instruments issued to a non-employee be measured on the earlier of: (i) the performance commitment date or (ii) the date the services required under the arrangement have been completed.

Certain of the performance based restricted stock units will only meet the requirements for establishing a grant date when the final calculated financial performance metrics and the amount of awards have been approved by the Company’s Board of Directors, which will then trigger the service inception date, the fair value of the awards, and the associated expense recognition period.

The fair value of the remaining stock-based payment awards is expensed over the vesting period of each tranche on a straight-line basis. Any modification of an award that increases its fair value will require the Company to recognize additional expense. The fair value of stock options under its employee stock incentive plan are estimated as of the grant date using the Black-Scholes option valuation model, which is affected by its expected dividend yield, expected term and the expected share price volatility of its common shares over the expected term. No dividend rates are used in the calculation as these are not applicable to the Company. Forfeitures are recognized as incurred. Employee options are accounted for in accordance with the guidance set forth by ASC 718, Stock Based Compensation.

Income Taxes

Income Taxes—The Company accounts for income taxes under the asset and liability method, which requires recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the period that includes the enacted date.

A valuation allowance is recorded when it is more-likely-than-not some of the deferred tax assets may not be realized. Significant judgment is applied when assessing the need for a valuation allowance and the Company considers all available positive and negative evidence, including future taxable income, reversals of existing deferred tax assets and liabilities and ongoing prudent and feasible tax planning strategies in making such assessment. Should a change in circumstances lead to a change in judgment regarding the utilization of deferred tax assets in future years, the Company will adjust the related valuation allowance in the period such change in circumstances occurs.

For acquired business entities, if the Company identifies changes to acquired deferred tax asset valuation allowances or liabilities related to uncertain tax positions during the measurement period, and they relate to new information obtained about facts and circumstances existing as of the acquisition date, those changes are considered a measurement period adjustment and the offset is recorded to goodwill.

The Company records uncertain tax positions on the basis of the two-step process in which (i) it determines whether it is more-likely-than-not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more-likely-than-not recognition threshold, the Company would recognize the largest amount of tax benefit that is more than 50.0% likely to be realized upon ultimate settlement with the related tax authority. The Company classifies interest and penalties recognized on uncertain tax positions as a component of income tax expense.
Reclassifications

Reclassifications—Certain prior year amounts, which are not material, have been reclassified to conform to current year presentation in the consolidated statements of cash flows and notes to the consolidated financial statements.
Recently Adopted Accounting Pronouncements /Recently Issued Accounting Pronouncements Not Yet Adopted

Recently Adopted Accounting Pronouncements

ASU 2023-05 —In August 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-05 Business Combinations — Joint Venture Formations (Subtopic 805-60): Recognition and Initial Measurement, under which an entity that qualifies as either a joint venture or a corporate joint venture is required to apply a new basis of accounting upon the formation of the joint venture. Specifically, the ASU provides that a joint venture or a corporate joint venture must initially measure its assets and liabilities at fair value on the formation date. The amendments in ASU 2023-05 are effective for all joint ventures within the ASU’s scope that are formed on or after January 1, 2025. The Company adopted the standard on January 1, 2025. The adoption of the standard did not have a material impact on the Company's consolidated financial statements.

ASU 2023-09 —In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures, which improves the transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the rate reconciliation and income taxes paid disaggregated by jurisdiction. It also includes certain other amendments to improve the effectiveness of income tax disclosures. ASU 2023-09 is effective for the Company's fiscal year beginning after December 15, 2024 and is being applied using the retrospective approach. The Company adopted the standard on January 1, 2025. The adoption did not have an impact on the recognition or measurement of income taxes in the Company's consolidated financial statements, and only required additional disclosures. The Company updated its income tax disclosures in accordance with the guidance.

Recently Issued Accounting Pronouncements Not Yet Adopted

ASU 2024-03 —In November 2024, the FASB issued ASU 2024-03, Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses (ASU 2024-03), which is intended to improve the disclosures about a public business entity’s expenses and address requests from investors for more detailed information about the types of expenses

in commonly presented expense captions (such as cost of sales; selling, general, and administrative expenses; and research and development). ASU 2024-03 is effective for the Company's fiscal year beginning January 1, 2027 and interim periods within fiscal years beginning after December 15, 2027, and allows the use of a prospective or retrospective approach. The Company plans to adopt the standard on January 1, 2027 and is currently evaluating the impact of the adoption of the standard on its consolidated financial statements.

ASU 2025-06 —In September 2025, the FASB issued ASU 2025-06, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software (ASU 2025-06), which removes all references to software development project stages, making the guidance neutral to different software development methodologies. Under the ASU, software capitalization will begin when management has authorized and committed to funding the software project and it is probable that the project will be completed and the software will be used as intended. ASU 2025-06 is effective for the Company's fiscal year beginning January 1, 2028, and interim periods within fiscal years beginning after December 15, 2027, and allows the use of a prospective, modified transition, or retrospective approach. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of the standard on its consolidated financial statements.
v3.25.4
Revenues and Accounts Receivable (Tables)
 12 Months Ended
Dec. 31, 2025
Revenues And Accounts Receivable [Abstract]  
Schedule of Contract Balances

The following table presents the Company’s contract balances as of December 31:

 

 

 

December 31,

 

 

December 31,

 

 

 

2025

 

 

2024

 

Contract assets

 

$

58,831

 

 

$

52,091

 

Contract liabilities

 

 

14,996

 

 

 

9,297

 

 
Schedule of Accounts Receivable, Net

Accounts receivable, net consisted of the following:

 

 

 

December 31, 2025

 

 

December 31, 2024

 

Accounts receivable, invoiced

 

$

163,694

 

 

$

160,976

 

Allowance for doubtful accounts

 

 

(8,314

)

 

 

(2,093

)

Accounts receivable, net

 

$

155,380

 

 

$

158,883

 
Schedule of Allowance for Doubtful Accounts

The allowance for doubtful accounts consisted of the following:

 

 

 

Beginning
Balance

 

 

Bad Debt
Expense
(Recovery)

 

 

Charged to
Allowance

 

 

Ending
Balance

 

Year ended December 31, 2025

 

$

2,093

 

 

$

6,713

 

 

$

(492

)

 

$

8,314

 

Year ended December 31, 2024

 

 

2,724

 

 

 

(146

)

 

 

(485

)

 

 

2,093

 

Year ended December 31, 2023

 

 

1,915

 

 

 

3,142

 

 (1)

 

(2,333

)

 (1)

 

2,724

 
(1)
Amount includes $2.2 million of current expected losses on the Discontinued Specialty Lab promissory note receivable as described in Note 8.
v3.25.4
Prepaid and Other Current Assets (Tables)
 12 Months Ended
Dec. 31, 2025
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]  
Schedule of Prepaid and Other Current Assets

Prepaid and other current assets consisted of the following:

 

 

 

December 31, 2025

 

 

December 31, 2024

 

Deposits

 

$

967

 

 

$

1,073

 

Prepaid expenses

 

 

11,367

 

 

 

10,223

 

Supplies

 

 

2,625

 

 

 

2,794

 

Prepaid and other current assets

 

$

14,959

 

 

$

14,090

 
v3.25.4
Property and Equipment, Net (Tables)
 12 Months Ended
Dec. 31, 2025
Property, Plant and Equipment [Abstract]  
Property and Equipment, Net

Property and equipment, net consisted of the following:

 

 

Estimated Useful Life

 

December 31, 2025

 

 

December 31, 2024

 

Lab and test equipment

7 years

 

$

24,604

 

 

$

24,421

 

Vehicles

5 years

 

 

6,696

 

 

 

6,360

 

Equipment

3-7 years

 

 

70,702

 

 

 

60,763

 

Furniture and fixtures

7 years

 

 

5,322

 

 

 

3,221

 

Leasehold improvements

7 years

 

 

15,335

 

 

 

14,029

 

Aircraft

10-20 years

 

 

12,386

 

 

 

12,386

 

Building

20-39 years

 

 

5,764

 

 

 

5,763

 

 

 

 

140,809

 

 

 

126,943

 

Land

 

 

 

1,089

 

 

 

1,089

 

Construction in progress

 

 

 

1,930

 

 

 

3,993

 

Less: Accumulated depreciation

 

 

 

(79,975

)

 

 

(68,249

)

Total property and equipment—net

 

 

$

63,853

 

 

$

63,776

 
v3.25.4
Leases (Tables)
 12 Months Ended
Dec. 31, 2025
Leases [Abstract]  
Summary of Components of Lease Expense

The components of lease expense were as follows:

 

 

 

 

 

For the Twelve Months Ended December 31,

 

 

 

Statement of Operations Location

 

2025

 

 

2024

 

Operating lease cost

 

 

 

 

 

 

 

 

Lease cost

 

Selling, general and administrative expense

 

$

12,511

 

 

$

13,667

 

Variable lease cost

 

Selling, general and administrative expense

 

 

3,036

 

 

 

2,217

 

Total operating lease cost

 

 

 

$

15,547

 

 

$

15,884

 

 

 

 

 

 

 

 

 

Finance lease cost

 

 

 

 

 

 

 

 

Amortization of ROU assets

 

Depreciation and amortization

 

$

8,694

 

 

$

5,814

 

Interest on lease liabilities

 

Interest expense, net

 

 

1,232

 

 

 

611

 

Total finance lease cost

 

 

 

$

9,926

 

 

$

6,425

 

Total lease cost

 

 

 

$

25,473

 

 

$

22,309

 
Summary of Supplemental Cash Flow Information Related To Leases

Supplemental cash flows information related to leases was as follows:

 

 

 

For the Twelve Months Ended December 31,

 

 

 

2025

 

 

2024

 

Cash paid for amounts included in the measurement of lease liabilities:

 

 

 

 

 

 

Operating cash flows used in operating leases

 

$

13,777

 

 

$

13,202

 

Operating cash flows used for interest related to finance leases

 

 

1,256

 

 

 

661

 

Financing cash flows used in finance leases

 

 

6,368

 

 

 

5,489

 

Lease liabilities arising from new ROU assets:

 

 

 

 

 

 

Operating leases

 

 

9,204

 

 

 

20,951

 

Finance leases

 

 

22,133

 

 

 

8,841

 
Summary of Weighted Average Remaining Lease Terms and Weighted Average Discount Rates

Weighted average remaining lease terms and weighted average discount rates were:

 

 

 

December 31, 2025

 

 

 

Operating Leases

 

 

Finance Leases

 

Weighted average remaining lease term (years)

 

 

4.9

 

 

 

9.7

 

Weighted average discount rate

 

 

5.1

%

 

 

6.7

%

 

 

 

 

 

 

 

 

 

December 31, 2024

 

 

 

Operating Leases

 

 

Finance Leases

 

Weighted average remaining lease term (years)

 

 

4.6

 

 

 

3.7

 

Weighted average discount rate

 

 

4.8

%

 

 

6.7

%

 
Schedule of Maturities of Lease Liabilities

The following is a schedule by year of the maturities of lease liabilities with original terms in excess of one year:

 

 

Operating Leases

 

 

Finance Leases

 

2026

 

$

12,394

 

 

$

8,479

 

2027

 

 

9,542

 

 

 

7,070

 

2028

 

 

7,868

 

 

 

5,405

 

2029

 

 

6,069

 

 

 

3,749

 

2030

 

 

2,839

 

 

 

1,947

 

2031 and thereafter

 

 

5,865

 

 

 

18,882

 

Total undiscounted future minimum lease payments

 

$

44,577

 

 

$

45,532

 

Less imputed interest

 

 

(5,627

)

 

 

(13,750

)

Total discounted future minimum lease payments

 

$

38,950

 

 

$

31,782

 
v3.25.4
Business Acquisitions and Dispositions (Tables)
 12 Months Ended
Dec. 31, 2025
Business Acquisition [Line Items]  
Weighted Average Useful Lives of Identifiable Intangible Assets The weighted average useful lives of identifiable intangible assets by major intangible asset class acquired during 2024 and 2023 is as follows:

 

 

2024

 

 

2023

 

Customer relationships

 

8.2

 

 

 

9.4

 

Covenants not to compete

 

5.0

 

 

 

4.9

 

Trade names

 

2.0

 

 

 

1.8

 

Proprietary software

 

—

 

 

 

3.0

 

Weighted average

 

5.3

 

 

 

4.7

 
Summary of Supplemental Unaudited Pro-Forma Information The unaudited consolidated financial information summarized in the following table gives effect to the 2024 and 2023 acquisitions assuming they occurred on January 1, 2023. These unaudited consolidated pro forma operating results include results from certain acquired companies that have not been audited and whose accounting policies prior to acquisition may differ from those of the Company. As a result, these unaudited consolidated pro forma operating results may not be comparable to revenues and earnings had these consolidated pro forma results been audited and consistent accounting policies applied. These unaudited consolidated pro forma operating results do not assume any impact from revenue, cost or other operating synergies that are expected or may have been realized as a result of the acquisitions. These unaudited consolidated pro forma operating results are presented for illustrative purposes only and are not indicative of the operating results that would have been achieved had the acquisitions occurred on January 1, 2023, nor does the information project results for any future period.

 

 

 

For the Twelve Months Ended December 31,

 

 

 

As reported

 

 

Acquisitions Pro-Forma (Unaudited)

 

 

Consolidated Pro-Forma (Unaudited)

 

2025

 

 

 

 

 

 

 

 

 

Revenues

 

$

830,538

 

 

$

—

 

 

$

830,538

 

Net (loss)

 

$

(843

)

 

$

—

 

 

$

(843

)

2024

 

 

 

 

 

 

 

 

 

Revenues

 

$

696,395

 

 

$

24,559

 

 

$

720,954

 

Net (loss) income

 

$

(62,314

)

 

$

9,413

 

 

$

(52,901

)

2023

 

 

 

 

 

 

 

 

 

Revenues

 

$

624,208

 

 

$

65,798

 

 

$

690,006

 

Net (loss) income

 

$

(30,859

)

 

$

8,110

 

 

$

(22,749

)

 
EPIC, 2DOT, ETA, Paragon, Spirit and Origins  
Business Acquisition [Line Items]  
Summary of Final Elements of Purchase Price of Acquisitions

The following table summarizes the final elements of the purchase price of the acquisitions completed during 2024:

 

 

 

Cash

 

 

Common Stock

 

 

Other Purchase Price Components

 

 

Contingent Consideration

 

 

Total Purchase Price

 

Epic

 

$

19,914

 

 

$

4,748

 

 

$

419

 

 

$

11,113

 

 

$

36,194

 

2DOT

 

 

39,393

 

 

 

1,832

 

 

 

(660

)

 

 

—

 

 

 

40,565

 

ETA

 

 

1,600

 

 

 

—

 

 

 

400

 

 

 

—

 

 

 

2,000

 

Paragon

 

 

10,773

 

 

 

2,691

 

 

 

125

 

 

 

—

 

 

 

13,589

 

Spirit

 

 

16,027

 

 

 

1,441

 

 

 

95

 

 

 

10,308

 

 

 

27,871

 

Origins

 

 

27,414

 

 

 

—

 

 

 

220

 

 

 

8,000

 

 

 

35,634

 

Total

 

$

115,121

 

 

$

10,712

 

 

$

599

 

 

$

29,421

 

 

$

155,853

 

 
Summary of Final Purchase Price Attributable to Acquisitions

The final purchase price attributable to the 2024 acquisitions was allocated as follows:

 

 

 

Epic (As Initially Reported)

 

 

Epic Measurement Period Adjustments

 

 

Epic (As Adjusted)

 

 

2DOT (As Initially Reported)

 

 

2DOT Measurement Period Adjustments

 

 

2DOT (As Adjusted)

 

 

ETA

 

 

Paragon

 

 

Spirit (As Initially Reported)

 

 

Spirit Measurement Period Adjustments

 

 

Spirit (As Adjusted)

 

 

Origins (As Initially Reported)

 

 

Origins Measurement Period Adjustments

 

 

Origins (As Adjusted)

 

 

Total

 

Cash

 

$

1,045

 

 

$

—

 

 

$

1,045

 

 

$

143

 

 

$

—

 

 

$

143

 

 

$

—

 

 

$

242

 

 

$

605

 

 

$

—

 

 

$

605

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

2,035

 

Accounts receivable and contract assets

 

 

1,772

 

 

 

—

 

 

 

1,772

 

 

 

740

 

 

 

—

 

 

 

740

 

 

 

—

 

 

 

3,188

 

 

 

2,393

 

 

 

—

 

 

 

2,393

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

8,093

 

Other current assets

 

 

78

 

 

 

—

 

 

 

78

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

85

 

 

 

119

 

 

 

—

 

 

 

119

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

282

 

Current assets

 

$

2,895

 

 

$

—

 

 

$

2,895

 

 

$

883

 

 

$

—

 

 

$

883

 

 

$

—

 

 

$

3,515

 

 

$

3,117

 

 

$

—

 

 

$

3,117

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

10,410

 

Property and equipment

 

 

43

 

 

 

—

 

 

 

43

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

341

 

 

 

145

 

 

 

—

 

 

 

145

 

 

 

1,787

 

 

 

—

 

 

 

1,787

 

 

 

2,316

 

Operating lease right-of-use asset

 

 

280

 

 

 

—

 

 

 

280

 

 

 

301

 

 

 

—

 

 

 

301

 

 

 

—

 

 

 

1,798

 

 

 

693

 

 

 

—

 

 

 

693

 

 

 

552

 

 

 

—

 

 

 

552

 

 

 

3,624

 

Customer relationships

 

 

12,053

 

 

 

—

 

 

 

12,053

 

 

 

9,521

 

 

 

—

 

 

 

9,521

 

 

 

—

 

 

 

4,209

 

 

 

4,090

 

 

 

—

 

 

 

4,090

 

 

 

7,305

 

 

 

—

 

 

 

7,305

 

 

 

37,178

 

Trade names

 

 

523

 

 

 

—

 

 

 

523

 

 

 

200

 

 

 

—

 

 

 

200

 

 

 

—

 

 

 

350

 

 

 

280

 

 

 

—

 

 

 

280

 

 

 

332

 

 

 

—

 

 

 

332

 

 

 

1,685

 

Covenants not to compete

 

 

1,817

 

 

 

—

 

 

 

1,817

 

 

 

2,940

 

 

 

—

 

 

 

2,940

 

 

 

—

 

 

 

45

 

 

 

700

 

 

 

—

 

 

 

700

 

 

 

87

 

 

 

—

 

 

 

87

 

 

 

5,589

 

Goodwill

 

 

25,102

 

 

 

(168

)

 

 

24,934

 

 

 

27,273

 

 

 

44

 

 

 

27,317

 

 

 

2,000

 

 

 

6,444

 

 

 

18,285

 

 

 

2,051

 

 

 

20,336

 

 

 

25,903

 

 

 

220

 

 

 

26,123

 

 

 

107,154

 

Total assets

 

$

42,713

 

 

$

(168

)

 

$

42,545

 

 

$

41,118

 

 

$

44

 

 

$

41,162

 

 

$

2,000

 

 

$

16,702

 

 

$

27,310

 

 

$

2,051

 

 

$

29,361

 

 

$

35,966

 

 

$

220

 

 

$

36,186

 

 

$

167,956

 

Current liabilities

 

 

1,994

 

 

 

—

 

 

 

1,994

 

 

 

404

 

 

 

—

 

 

 

404

 

 

 

—

 

 

 

1,572

 

 

 

1,490

 

 

 

—

 

 

 

1,490

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

5,460

 

Deferred tax liability

 

 

4,214

 

 

 

—

 

 

 

4,214

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

4,214

 

Operating lease liability—net of current portion

 

 

—

 

 

 

—

 

 

 

—

 

 

 

193

 

 

 

—

 

 

 

193

 

 

 

—

 

 

 

1,513

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

552

 

 

 

—

 

 

 

552

 

 

 

2,258

 

Other non-current liabilities

 

 

143

 

 

 

—

 

 

 

143

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

28

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

171

 

Total liabilities

 

$

6,351

 

 

$

—

 

 

$

6,351

 

 

$

597

 

 

$

—

 

 

$

597

 

 

$

—

 

 

$

3,113

 

 

$

1,490

 

 

$

—

 

 

$

1,490

 

 

$

552

 

 

$

—

 

 

$

552

 

 

$

12,103

 

Purchase price

 

$

36,362

 

 

$

(168

)

 

$

36,194

 

 

$

40,521

 

 

$

44

 

 

$

40,565

 

 

$

2,000

 

 

$

13,589

 

 

$

25,820

 

 

$

2,051

 

 

$

27,871

 

 

$

35,414

 

 

$

220

 

 

$

35,634

 

 

$

155,853

 
Frontier, EAI, GreenPath, Matrix, Vandrensning  
Business Acquisition [Line Items]  
Summary of Final Elements of Purchase Price of Acquisitions

The following table summarizes the final elements of the purchase price of the acquisitions completed during 2023:

 

 

Cash

 

 

Common Stock

 

 

Other Purchase Price Components

 

 

Contingent Consideration

 

 

Total Purchase Price

 

2023 Acquisitions

 

$

68,640

 

 

$

2,598

 

 

$

1,603

 

 

$

1,096

 

 

$

73,937

 

 
Summary of Final Purchase Price Attributable to Acquisitions

The final purchase price attributable to the 2023 acquisitions was allocated as follows:

 

 

2023 Acquisitions (As Initially Reported)

 

 

2024 Measurement Period Adjustments

 

 

2024 (Final Amount)

 

Cash

 

$

2,453

 

 

 

—

 

 

$

2,453

 

Accounts receivable and contract assets

 

 

19,174

 

 

 

—

 

 

 

19,174

 

Other current assets

 

 

2,185

 

 

 

—

 

 

 

2,185

 

Current assets

 

 

23,812

 

 

 

—

 

 

 

23,812

 

Property and equipment

 

 

3,936

 

 

 

—

 

 

 

3,936

 

Operating lease right-of-use asset

 

 

4,825

 

 

 

—

 

 

 

4,825

 

Customer relationships

 

 

19,962

 

 

 

—

 

 

 

19,962

 

Trade names

 

 

2,373

 

 

 

—

 

 

 

2,373

 

Covenants not to compete

 

 

2,708

 

 

 

—

 

 

 

2,708

 

Other intangible assets

 

 

444

 

 

 

—

 

 

 

444

 

Goodwill

 

 

40,786

 

 

 

(866

)

 

 

39,920

 

Total assets

 

 

98,846

 

 

 

(866

)

 

 

97,980

 

Current liabilities

 

 

11,557

 

 

 

—

 

 

 

11,557

 

Operating lease liability—net of current portion

 

 

10,357

 

 

 

—

 

 

 

10,357

 

Deferred tax liability

 

 

1,999

 

 

 

—

 

 

 

1,999

 

Other non-current liabilities

 

 

130

 

 

 

—

 

 

 

130

 

Total liabilities

 

 

24,043

 

 

 

—

 

 

 

24,043

 

Purchase price

 

$

74,803

 

 

$

(866

)

 

$

73,937

 
v3.25.4
Goodwill and Intangible Assets (Tables)
 12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of Amounts Related to Goodwill

Amounts related to goodwill are as follows:

 

 

 

Assessment, Permitting and Response

 

 

Measurement and Analysis

 

 

Remediation and Reuse

 

 

Total

 

Balance as of December 31, 2024

 

$

205,231

 

 

$

118,860

 

 

$

143,698

 

 

$

467,789

 

Acquisitions measurement period adjustments, net of foreign currency translation

 

 

1,501

 

 

 

220

 

 

 

(80

)

 

 

1,641

 

Goodwill disposed during the period(1)

 

 

—

 

 

 

—

 

 

 

(2,644

)

 

 

(2,644

)

Balance as of December 31, 2025

 

$

206,732

 

 

$

119,080

 

 

$

140,974

 

 

$

466,786

 

 

(1) Goodwill disposed during the period is due to the disposition of the Company's business in Denmark
Schedule of Amounts Related to Finite-Lived Intangible Assets

Amounts related to finite-lived intangible assets are as follows:

 

December 31, 2025

 

Estimated Useful Life

 

Gross Balance

 

 

Accumulated Amortization

 

 

Total Intangible Assets—Net

 

Customer relationships

 

2-15 years

 

$

264,564

 

 

$

160,459

 

 

$

104,105

 

Covenants not to compete

 

4-5 years

 

 

41,418

 

 

 

36,293

 

 

 

5,125

 

Trade names

 

1-5 years

 

 

25,917

 

 

 

25,441

 

 

 

476

 

Proprietary software

 

3-5 years

 

 

31,982

 

 

 

25,912

 

 

 

6,070

 

Patent

 

16 years

 

 

17,479

 

 

 

6,872

 

 

 

10,607

 

Total other intangible assets, net

 

 

 

$

381,360

 

 

$

254,977

 

 

$

126,383

 

 

 

 

 

 

 

 

 

 

 

 

 

December 31, 2024

 

Estimated Useful Life

 

Gross Balance

 

 

Accumulated Amortization

 

 

Total Intangible Assets—Net

 

Customer relationships

 

2-15 years

 

$

264,477

 

 

$

138,787

 

 

$

125,690

 

Covenants not to compete

 

4-5 years

 

 

41,758

 

 

 

33,898

 

 

 

7,860

 

Trade names

 

1-5 years

 

 

25,939

 

 

 

23,375

 

 

 

2,564

 

Proprietary software

 

3-5 years

 

 

28,428

 

 

 

23,489

 

 

 

4,939

 

Patent

 

16 years

 

 

17,479

 

 

 

5,776

 

 

 

11,703

 

Total other intangible assets, net

 

 

 

$

378,081

 

 

$

225,325

 

 

$

152,756

 

 
Schedule of Future Amortization Expense

Future amortization expense is estimated to be as follows for each of the five following years and thereafter ending December 31:

 

December 31,

 

 

 

2026

 

$

25,371

 

2027

 

 

24,258

 

2028

 

 

18,664

 

2029

 

 

12,773

 

2030

 

 

9,418

 

Thereafter

 

 

35,899

 

Total

 

$

126,383

 
v3.25.4
Accounts Payable and Other Accrued Liabilities (Tables)
 12 Months Ended
Dec. 31, 2025
Payables and Accruals [Abstract]  
Summary of Accounts Payable and Other Accrued Liabilities

Accounts payable and other accrued liabilities consisted of the following:

 

 

 

December 31, 2025

 

 

December 31, 2024

 

Accounts payable

 

$

34,806

 

 

$

33,424

 

Accrued expenses

 

 

18,373

 

 

 

16,190

 

Contract liabilities

 

 

14,996

 

 

 

9,297

 

Other current liabilities

 

 

3,603

 

 

 

4,793

 

Total accounts payable and other accrued liabilities

 

$

71,778

 

 

$

63,704

 
v3.25.4
Accrued Payroll and Benefits (Tables)
 12 Months Ended
Dec. 31, 2025
Statement of Financial Position [Abstract]  
Schedule of Accrued Payroll and Benefits

Accrued payroll and benefits consisted of the following:

 

 

 

December 31, 2025

 

 

December 31, 2024

 

Accrued bonuses

 

$

28,568

 

 

$

14,433

 

Accrued payroll

 

 

13,501

 

 

 

11,969

 

Accrued paid time off

 

 

3,603

 

 

 

4,214

 

Accrued medical

 

 

2,305

 

 

 

1,589

 

Accrued other

 

 

4,796

 

 

 

2,043

 

Total accrued payroll and benefits

 

$

52,773

 

 

$

34,248

 
v3.25.4
Income Taxes (Tables)
 12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Summary of Geographical Breakdown of Income (Loss) Before Provision for Income (Loss) Taxes

The following is a geographical breakdown of income (loss) before the provision for income (loss) taxes as of December 31:

 

 

 

2025

 

 

2024

 

 

2023

 

Pre-tax income (loss):

 

 

 

 

 

 

 

 

 

Federal

 

$

17,189

 

 

$

(54,860

)

 

$

(35,111

)

Foreign

 

 

(5,968

)

 

 

542

 

 

 

3,272

 

Total

 

$

11,221

 

 

$

(54,318

)

 

$

(31,839

)

 
Summary of Income Tax Expense (Benefit)

Income tax expense (benefit) for the years ended December 31, is comprised of the following:

 

 

 

2025

 

 

2024

 

 

2023

 

Current:

 

 

 

 

 

 

 

 

 

Federal

 

$

29

 

 

$

244

 

 

$

—

 

State

 

 

2,271

 

 

 

817

 

 

 

1,840

 

Foreign

 

 

1,081

 

 

 

1,887

 

 

 

(1,131

)

Total current tax expense

 

 

3,381

 

 

 

2,948

 

 

 

709

 

Deferred:

 

 

 

 

 

 

 

 

 

Federal

 

 

10,053

 

 

 

1,160

 

 

 

(438

)

State

 

 

(452

)

 

 

1,850

 

 

 

(960

)

Foreign

 

 

(918

)

 

 

2,038

 

 

 

(291

)

Total deferred tax expense

 

 

8,683

 

 

 

5,048

 

 

 

(1,689

)

Total:

 

 

 

 

 

 

 

 

 

Federal

 

 

10,082

 

 

 

1,404

 

 

 

(438

)

State

 

 

1,819

 

 

 

2,667

 

 

 

880

 

Foreign

 

 

163

 

 

 

3,925

 

 

 

(1,422

)

Income tax expense (benefit)

 

$

12,064

 

 

$

7,996

 

 

$

(980

)
Schedule of Significant Components of Deferred Tax Assets and Liabilities

Significant components of the Company’s deferred tax assets and liabilities as of December 31, are as follows:

 

 

 

2025

 

 

2024

 

Deferred tax assets:

 

 

 

 

 

 

Net operating losses

 

$

11,000

 

 

$

14,021

 

Section 163(j) interest limitation

 

 

3,058

 

 

 

7,627

 

Equity compensation

 

 

2,063

 

 

 

7,669

 

Contingent consideration

 

 

8,621

 

 

 

9,007

 

Lease liabilities

 

 

17,182

 

 

 

(15,274

)

Accrued compensation

 

 

6,991

 

 

 

4,117

 

Transaction costs

 

 

2,384

 

 

 

2,525

 

Section 174 research & experimental

 

 

648

 

 

 

1,312

 

Interest rate swap

 

 

106

 

 

 

(402

)

Other

 

 

8,067

 

 

 

6,593

 

Total deferred tax asset

 

 

60,120

 

 

 

37,195

 

Deferred tax liabilities:

 

 

 

 

 

 

Intangible assets

 

 

(24,650

)

 

 

(22,399

)

Property and equipment

 

 

(14,104

)

 

 

(13,944

)

ROU assets

 

 

(18,027

)

 

 

14,986

 

Other

 

 

(90

)

 

 

(1,529

)

Total deferred tax liability

 

 

(56,871

)

 

 

(22,886

)

Valuation allowance

 

 

(25,066

)

 

 

(27,621

)

Net deferred tax liability

 

$

(21,817

)

 

$

(13,312

)

 
Effective Tax Rate of Company's Provision (Benefit) for Income Taxes Differs from Federal Statutory Rate

The effective tax rate of the Company's provision (benefit) for income taxes differs from the federal statutory rate for the years ended December 31, are as follows:

 

 

 

2025

 

 

2024

 

 

2023

 

 

US federal statutory tax rate

 

$

2,356

 

 

 

21.00

 

%

$

(11,408

)

 

 

21.00

 

%

$

(6,686

)

 

 

21.00

 

%

State and local income taxes, net of federal income tax effect(1)

 

 

1,150

 

 

 

10.25

 

 

 

2,511

 

 

 

(4.62

)

 

 

477

 

 

 

(1.50

)

 

Effect of cross-border tax laws

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Global intangible low-taxed income

 

 

316

 

 

 

2.81

 

 

 

1,410

 

 

 

(2.60

)

 

 

1,067

 

 

 

(3.35

)

 

US tax impact of foreign branches

 

 

(174

)

 

 

(1.55

)

 

 

(501

)

 

 

0.92

 

 

 

(148

)

 

 

0.47

 

 

Sale of Denmark business

 

 

566

 

 

 

5.05

 

 

 

—

 

 

 

0.00

 

 

 

—

 

 

 

0.00

 

 

Tax credits

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Federal research and development credit

 

 

(1,139

)

 

 

(10.15

)

 

 

—

 

 

 

0.00

 

 

 

—

 

 

 

0.00

 

 

Change in valuation allowance

 

 

157

 

 

 

1.40

 

 

 

(911

)

 

 

1.68

 

 

 

(4,421

)

 

 

13.88

 

 

Nondeductible items

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Equity compensation

 

 

7,636

 

 

 

68.06

 

 

 

1,519

 

 

 

(2.80

)

 

 

539

 

 

 

(1.69

)

 

Mark to market - fair value derivative

 

 

(4,247

)

 

 

(37.85

)

 

 

253

 

 

 

(0.47

)

 

 

(1,410

)

 

 

4.43

 

 

Meals

 

 

365

 

 

 

3.25

 

 

 

365

 

 

 

(0.67

)

 

 

526

 

 

 

(1.65

)

 

Transaction expense - deemed contribution to controlled foreign corporation

 

 

—

 

 

 

0.00

 

 

 

318

 

 

 

(0.59

)

 

 

492

 

 

 

(1.55

)

 

Worldwide changes in unrecognized tax benefits

 

 

624

 

 

 

5.56

 

 

 

—

 

 

 

0.00

 

 

 

—

 

 

 

0.00

 

 

Other

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Federal deferred tax adjustments

 

 

1,346

 

 

 

12.00

 

 

 

10,659

 

 

 

(19.62

)

 

 

9,606

 

 

 

(30.17

)

 

Federal tax return true up

 

 

222

 

 

 

1.98

 

 

 

(940

)

 

 

1.73

 

 

 

448

 

 

 

(1.41

)

 

Section 162(m) compensation deduction limitation

 

 

1,229

 

 

 

10.95

 

 

 

183

 

 

 

(0.34

)

 

 

22

 

 

 

(0.07

)

 

Other

 

 

239

 

 

 

2.13

 

 

 

725

 

 

 

(1.34

)

 

 

539

 

 

 

(1.69

)

 

Foreign tax effects

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Canada

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rate differential

 

 

(203

)

 

 

(1.81

)

 

 

18

 

 

 

(0.03

)

 

 

153

 

 

 

(0.48

)

 

Return-to-provision adjustments

 

 

756

 

 

 

6.74

 

 

 

2,953

 

 

 

(5.44

)

 

 

(466

)

 

 

1.46

 

 

Impact of scientific research and experimental development credits

 

 

(641

)

 

 

(5.72

)

 

 

269

 

 

 

(0.50

)

 

 

(2,028

)

 

 

6.37

 

 

Other

 

 

67

 

 

 

0.60

 

 

 

(101

)

 

 

0.19

 

 

 

11

 

 

 

(0.04

)

 

Australia

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rate differential

 

 

999

 

 

 

8.90

 

 

 

172

 

 

 

(0.32

)

 

 

46

 

 

 

(0.14

)

 

Change in valuation allowance

 

 

—

 

 

 

0.00

 

 

 

—

 

 

 

0.00

 

 

 

(153

)

 

 

0.48

 

 

Other foreign jurisdictions

 

 

440

 

 

 

3.91

 

 

 

502

 

 

 

(0.63

)

 

 

406

 

 

 

(1.02

)

 

Total

 

$

12,064

 

 

 

107.51

 

%

$

7,996

 

 

 

(14.45

)

%

$

(980

)

 

 

3.33

 

%

 

(1) In each year, the state and local income taxes which comprise the majority of the state and local income taxes, net of federal effect category are California and Pennsylvania.
Schedule of Cash Paid for Income Taxes (Net of Refund)

The cash paid for income taxes (net of refunds) during the year was as follows:

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

Federal

 

$

540

 

 

$

—

 

 

$

—

 

State and local

 

 

 

 

 

 

 

 

 

Pennsylvania

 

 

213

 

 

 

307

 

 

 

614

 

Texas

 

 

200

 

 

 

219

 

 

 

(129

)

Alabama

 

 

613

 

 

 

89

 

 

 

9

 

California

 

 

1,045

 

 

 

87

 

 

 

10

 

Other

 

 

1,200

 

 

 

1,572

 

 

 

493

 

Total state and local

 

 

3,271

 

 

 

2,274

 

 

 

997

 

Foreign

 

 

 

 

 

 

 

 

 

Canada

 

 

195

 

 

 

1,232

 

 

 

—

 

Australia

 

 

1,499

 

 

 

688

 

 

 

—

 

Total foreign

 

 

1,694

 

 

 

1,920

 

 

 

—

 

Total

 

$

5,505

 

 

$

4,194

 

 

$

997

 
Schedule of Unrecognized Tax Positions The following table summarizes the gross amount of the Company’s uncertain tax positions:

 

 

 

2025

 

Balance at beginning of the year

 

$

—

 

Increases related to prior year tax positions

 

 

334

 

Decreases related to prior year tax positions

 

 

—

 

Increases related to current year tax positions

 

 

289

 

Decreases related to lapse of statute of limitations

 

 

—

 

Balance at end of the year

 

$

623

 
v3.25.4
Debt (Tables)
 12 Months Ended
Dec. 31, 2025
Debt Disclosure [Abstract]  
Schedule of Debt

Debt consisted of the following:

 

 

 

December 31, 2025

 

 

December 31, 2024

 

Term loan facility

 

$

197,500

 

 

$

189,218

 

Revolving line of credit

 

 

84,663

 

 

 

25,191

 

Aircraft loan

 

 

8,125

 

 

 

9,272

 

Less deferred debt issuance costs

 

 

(1,993

)

 

 

(997

)

Total debt

 

$

288,295

 

 

$

222,684

 

Less current portion of long-term debt

 

 

(11,230

)

 

 

(17,866

)

Long-term debt, less current portion

 

$

277,065

 

 

$

204,818

 
Summary of 2025 Credit Facility Term Loan and Revolving Line of Credit Interest Rate Subject to Leverage Ratio and SOFR

The 2025 Credit Facility term loan and the revolving line of credit bear interest subject to the applicable spread based on the Company’s leverage ratio and SOFR as follows:

 

Pricing Tier

 

Consolidated
Leverage Ratio

 

Senior Credit Facilities
Benchmark Spread

 

 

Senior Credit Facilities
Base Rate Spread

 

 

Commitment
Fee

 

 

Letter of
Credit Fee

 

 

1

 

≥ 3.75x to 1.0

 

 

2.50

 

%

 

1.50

 

%

 

0.25

 

%

 

2.50

 

%

2

 

< 3.75x to 1.0 but ≥ 3.25 to 1.0

 

 

2.25

 

 

 

1.25

 

 

 

0.23

 

 

 

2.25

 

 

3

 

<3.25x to 1.0 but ≥ 2.50 to 1.0

 

 

2.00

 

 

 

1.00

 

 

 

0.20

 

 

 

2.00

 

 

4

 

<2.50x to 1.0 but ≥ 1.75 to 1.0

 

 

1.75

 

 

 

0.75

 

 

 

0.15

 

 

 

1.75

 

 

5

 

<1.75x to 1.0

 

 

1.50

 

 

 

0.50

 

 

0.15

 

 

 

1.50

 

 
Schedule of Interest Rate Swap Agreements

As of December 31, 2025, the Company had the following interest rate swap agreements in place:

 

Effective date

 

Expiration date

 

Notional amount

 

 

Fixed rate

 

Floating rate

5/30/2023

 

4/27/2026

 

$

70,000,000

 

 

3.880%

 

USD-SOFR

6/5/2024

 

6/27/2027

 

$

80,000,000

 

 

3.270%

 

USD-SOFR

4/1/2025

 

4/27/2028

 

$

50,000,000

 

 

3.625%

 

USD-SOFR
Schedule of Aggregate Annual Maturities of Long-Term Debt (Excluding Current Portion)

The following is a schedule of the aggregate annual maturities of long-term debt (excluding current portion) presented on the consolidated statement of financial position as of December 31, 2025, before deferred debt issuance cost of $2.0 million, based on the terms of the 2025 Credit Facility and the Aircraft Loan:

 

 

 

2025 Credit Facility

 

 

 

 

 

 

 

Term Loan

 

Revolving Line of Credit

 

Aircraft Loan

 

Total

 

2027

 

$

10,000

 

$

—

 

$

1,318

 

$

11,318

 

2028

 

 

10,000

 

 

—

 

 

577

 

 

10,577

 

2029

 

 

10,000

 

 

—

 

 

5,000

 

 

15,000

 

2030

 

 

157,500

 

 

84,663

 

 

—

 

 

242,163

 

Total

 

$

187,500

 

$

84,663

 

$

6,895

 

$

279,058

 
v3.25.4
Fair Value of Financial Instruments (Tables)
 12 Months Ended
Dec. 31, 2025
Fair Value Disclosures [Abstract]  
Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis using Significant Unobservable Inputs (Level 3)

The following financial assets and liabilities are measured at fair value on a recurring basis using significant unobservable inputs (Level 3):

 

 

December 31, 2025

 

 

December 31, 2024

 

Interest rate swap(1)

$

—

 

 

$

1,544

 

Total Assets

$

—

 

 

$

1,544

 

 

 

 

 

 

 

Business acquisitions contingent consideration, current

$

14,883

 

 

$

26,872

 

Business acquisitions contingent consideration, long-term

 

2,755

 

 

 

6,255

 

Conversion option

 

—

 

 

 

20,224

 

Interest rate swap (1)

 

429

 

 

 

—

 

Total Liabilities

$

18,067

 

 

$

53,351

 

 

(1) Included in other non-current liabilities and other assets in the consolidated statement of financial position as of December 31, 2025 and consolidated statement of financial position as of December 31, 2024, respectively.
Summary of Financial Instruments Measured at Fair Value on Recurring Basis

The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis:

 

 

Interest Rate Swap

 

 

Total Assets

 

 

Business Acquisitions Contingent Consideration, Current

 

 

Business Acquisitions Contingent Consideration, Long-term

 

 

Conversion Option

 

 

Interest Rate Swap

 

 

Total Liabilities

 

Balance as of December 31, 2022

$

6,046

 

 

$

6,046

 

 

$

3,801

 

 

$

4,454

 

 

$

25,731

 

 

$

—

 

 

$

33,986

 

Acquisitions

 

—

 

 

 

—

 

 

 

397

 

 

 

730

 

 

 

—

 

 

 

—

 

 

 

1,127

 

Changes in fair value included in earnings

 

(2,585

)

 

 

(2,585

)

 

 

(174

)

 

 

(22

)

 

 

(6,714

)

 

 

—

 

 

 

(6,910

)

Payment of contingent consideration payable

 

—

 

 

 

—

 

 

 

(3,146

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(3,146

)

Reclass of long term to short term contingent liabilities

 

—

 

 

 

—

 

 

 

2,714

 

 

 

(2,714

)

 

 

—

 

 

 

—

 

 

 

—

 

Balance as of December 31, 2023

$

3,461

 

 

$

3,461

 

 

$

3,592

 

 

$

2,448

 

 

$

19,017

 

 

$

—

 

 

$

25,057

 

Acquisitions

 

—

 

 

 

—

 

 

 

5,104

 

 

 

22,899

 

 

 

—

 

 

 

—

 

 

 

28,003

 

Changes in fair value included in earnings

 

(1,917

)

 

 

(1,917

)

 

 

1,879

 

 

 

(1,345

)

 

 

1,207

 

 

 

—

 

 

 

1,741

 

Payment of contingent consideration payable

 

—

 

 

 

—

 

 

 

(1,450

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(1,450

)

Reclass of long term to short term contingent liabilities

 

—

 

 

 

—

 

 

 

17,747

 

 

 

(17,747

)

 

 

—

 

 

 

—

 

 

 

—

 

Balance as of December 31, 2024

$

1,544

 

 

$

1,544

 

 

$

26,872

 

 

$

6,255

 

 

$

20,224

 

 

$

—

 

 

$

53,351

 

Changes in fair value included in earnings

 

(1,544

)

 

 

(1,544

)

 

 

(180

)

 

 

1,080

 

 

 

(20,224

)

 

 

429

 

 

 

(18,895

)

Payment of contingent consideration payable

 

—

 

 

 

—

 

 

 

(17,937

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(17,937

)

Reclass of long term to short term contingent liabilities

 

—

 

 

 

—

 

 

 

4,580

 

 

 

(4,580

)

 

 

—

 

 

 

—

 

 

 

—

 

Measurement period adjustment

 

—

 

 

 

—

 

 

 

1,548

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

1,548

 

Balance as of December 31, 2025

$

—

 

 

$

—

 

 

$

14,883

 

 

$

2,755

 

 

$

—

 

 

$

429

 

 

$

18,067

 
v3.25.4
Stockholders' Equity (Tables)
 12 Months Ended
Dec. 31, 2025
Schedule of Share Authorized to be Issue and Available for Grant The following number of shares were authorized to be issued and available for grant as of:

 

 

December 31, 2025

 

 

2017 Plan

 

 

2013 Plan

 

 

Total

 

Shares authorized to be issued

 

8,914,149

 

 

 

2,032,719

 

 

 

10,946,868

 

Shares available for grant(1)

 

2,359,812

 

 

 

—

 

 

 

2,359,812

 

 

 

 

 

 

 

 

 

 

 

December 31, 2024

 

 

2017 Plan

 

 

2013 Plan

 

 

Total

 

Shares authorized to be issued

 

7,538,276

 

 

 

2,036,219

 

 

 

9,574,495

 

Shares available for grant(1)

 

1,683,352

 

 

 

—

 

 

 

1,683,352

 

 

 

 

 

 

 

 

 

 

 

December 31, 2023

 

 

2017 Plan

 

 

2013 Plan

 

 

Total

 

Shares authorized to be issued

 

6,330,713

 

 

 

2,036,219

 

 

 

8,366,932

 

Shares available for grant(1)

 

662,662

 

 

 

—

 

 

 

662,662

 

 

(1) In January 2025, January 2024 and January 2023 the Board of Directors ratified the addition of 1,372,373, 1,207,563 and 1,189,801 shares of common stock, respectively, to the number of shares available for issuance under the 2017 Plan pursuant to the annual increase provision of such plan. Unless the Board of Directors determines otherwise, additional annual increases will be effective on each January 1, through January 1, 2027. The 2017 Plan permits the company to settle awards, if and when vested, in cash at its discretion. Pursuant to the terms of the 2017 Plan, the number of shares authorized for issuance thereunder will only be reduced with respect to shares of common stock actually issued upon exercise or settlement of an award. Shares of common stock subject to awards that have been canceled, expired, forfeited or otherwise not issued under an award and shares of common stock subject to awards settled in cash do not

count as shares of common stock issued under the 2017 Plan. Shares available for grant as of December 31, 2023 excluded awards of stock appreciation rights approved in December 2021 that were subject to vesting based on the achievement of certain market conditions, which had not yet been achieved when these awards were cancelled, effective as of December 31, 2024. See “Stock Appreciation Rights” below for additional information on stock appreciation rights.
Schedule of Stock Compensation Expense

Total stock compensation expense for the Plans was as follows:

 

 

Year Ended December 31, 2025

 

 

Options

 

 

RSUs

 

 

SARs

 

 

Total

 

Cost of revenue

$

729

 

 

$

4,629

 

 

$

—

 

 

$

5,358

 

Selling, general and administrative expense

 

875

 

 

 

36,483

 

 

 

—

 

 

 

37,358

 

Total

$

1,604

 

 

$

41,112

 

 

$

—

 

 

$

42,716

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Year Ended December 31, 2024

 

 

Options

 

 

RSUs

 

 

SARs

 

 

Total

 

Cost of revenue

$

1,223

 

 

$

3,578

 

 

$

—

 

 

$

4,801

 

Selling, general and administrative expense

 

2,571

 

 

 

30,088

 

 

 

27,205

 

 

 

59,864

 

Total

$

3,794

 

 

$

33,666

 

 

$

27,205

 

 

$

64,665

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Year Ended December 31, 2023

 

 

Options

 

 

RSUs

 

 

SARs

 

 

Total

 

Cost of revenue

$

1,685

 

 

$

1,661

 

 

$

—

 

 

$

3,346

 

Selling, general and administrative expense

 

4,885

 

 

 

29,851

 

 

 

9,185

 

 

 

43,921

 

Total

$

6,570

 

 

$

31,512

 

 

$

9,185

 

 

$

47,267

 
Summary of Weighted Average Assumptions Used in Black-Sholes Option-pricing Model

The following weighted-average assumptions were used in the Black-Scholes option-pricing model calculation for 2023. There were no stock options granted in 2025 and 2024.

 

 

December 31, 2023

 

Common stock value (per share)

$

32.41

 

Expected volatility

 

33.55

%

Risk-free interest rate

 

3.77

%

Expected life (years)

 

7.00

 

Forfeiture rate

None

 

Dividend rate

None

 

 
Schedule of Common Stock Reserved for Future Issuance The Company has reserved certain stock of its authorized but unissued common stock for possible future issuance in connection with the following:

 

 

December 31,

 

 

2025

 

 

2024

 

 

2023

 

Montrose 2013 Stock Incentive Plan

 

567,827

 

 

 

680,889

 

 

 

792,191

 

Montrose 2017 Stock Incentive Plan(1)

 

6,877,744

 

 

 

6,645,618

 

 

 

8,647,656

 

 

7,445,571

 

 

 

7,326,507

 

 

 

9,439,847

 

 

(1) In January 2025, January 2024 and January 2023 the Board of Directors ratified the addition of 1,372,373, 1,207,563 and 1,189,801 shares of common stock, respectively, to the number of shares available for issuance under the 2017 Plan pursuant to the annual increase provision of such plan. Unless the Board of Directors determines otherwise, additional annual increases will be effective on each January 1, through January 1, 2027. The 2017 Plan permits the company to settle awards, if and when vested, in cash at its discretion. Pursuant to the terms of the 2017 Plan, the number of shares authorized for issuance thereunder will only be reduced with respect to shares of common stock actually issued upon exercise or settlement of an award. Shares of common stock subject to awards that have been canceled, expired, forfeited or otherwise not issued under an award and shares of common stock subject to awards settled in cash do not count as shares of common stock issued under the 2017 Plan. Shares reserved for future issuance as of December 31, 2023 includes awards of SARs approved in December 2021 that were subject to vesting based on the achievement of certain market conditions, which had not yet been achieved when these awards were cancelled, effective as of December 31, 2024. See “Stock Appreciation Rights” above for additional information on stock appreciation rights.
Montrose Amended & Restated 2017 Stock Incentive Plan  
Schedule of Restricted Stock Activity

RSA and RSU activity was as follows:

 

Year Ended December 31,

 

 

2025

 

 

2024

 

 

2023

 

 

Shares

 

 

Weighted-Average Grant Date Fair Value

 

 

Shares

 

 

Weighted-Average Grant Date Fair Value

 

 

Shares

 

 

Weighted-Average Grant Date Fair Value

 

Beginning outstanding shares

 

2,617,059

 

 

 

 

 

 

2,468,722

 

 

 

 

 

 

1,777,715

 

 

 

 

Granted

 

1,399,351

 

 

$

18.27

 

 

 

359,749

 

 

$

39.75

 

 

 

793,133

 

 

$

34.33

 

Forfeited/ cancelled

 

(166,158

)

 

$

27.76

 

 

 

(56,921

)

 

$

37.32

 

 

 

(11,311

)

 

$

32.13

 

Vested(1)

 

(1,525,848

)

 

$

49.25

 

 

 

(154,491

)

 

$

36.82

 

 

 

(90,815

)

 

$

36.77

 

Ending outstanding shares

 

2,324,404

 

 

 

 

 

 

2,617,059

 

 

 

 

 

 

2,468,722

 

 

 

 

 

(1) The 2025 vested shares amount includes 406,655 shares withheld related to net share settlement of equity awards.
Summary of Stock Option Activity The following summarizes the options activity of the 2017 Plan for the years ended December 31, 2025, 2024 and 2023:

 

 

Options to Purchase Common Stock

 

 

Weighted-Average Exercise Price per Share

 

 

Weighted-Average Grant Date Fair Value per Share

 

 

Weighted-Average Remaining Contract Life (in Years)

 

 

Aggregate Intrinsic Value of In-The-Money Options

 

Outstanding as of December 31, 2022

 

2,579,566

 

 

$

31.00

 

 

$

15.00

 

 

 

7.8

 

 

$

37,295

 

Granted

 

253,980

 

 

 

32.41

 

 

 

13.98

 

 

 

—

 

 

 

—

 

Forfeited/ cancelled

 

(134,170

)

 

 

36.01

 

 

 

—

 

 

 

—

 

 

 

—

 

Expired

 

(6,450

)

 

 

32.03

 

 

 

—

 

 

 

—

 

 

 

—

 

Exercised

 

(176,654

)

 

 

24.12

 

 

 

—

 

 

 

—

 

 

 

3,726

 

Outstanding as of December 31, 2023

 

2,516,272

 

 

$

30.92

 

 

$

15.95

 

 

 

7.0

 

 

$

13,825

 

Forfeited/ cancelled

 

(78,130

)

 

 

38.57

 

 

 

—

 

 

 

—

 

 

 

—

 

Expired

 

(37,825

)

 

 

41.90

 

 

 

—

 

 

 

—

 

 

 

—

 

Exercised

 

(55,110

)

 

 

25.48

 

 

 

—

 

 

 

—

 

 

 

776

 

Outstanding as of December 31, 2024

 

2,345,207

 

 

$

30.62

 

 

$

16.32

 

 

 

6.0

 

 

$

776

 

Forfeited/ cancelled

 

(55,313

)

 

 

40.81

 

 

 

—

 

 

 

—

 

 

 

—

 

Expired

 

(71,812

)

 

 

37.12

 

 

 

—

 

 

 

—

 

 

 

—

 

Exercised

 

(24,554

)

 

 

14.88

 

 

 

—

 

 

 

—

 

 

 

266

 

Outstanding as of December 31, 2025

 

2,193,528

 

 

$

30.33

 

 

$

16.32

 

 

 

4.9

 

 

$

6,109

 

Exercisable as of December 31, 2025

 

1,992,545

 

 

$

29.41

 

 

 

 

 

 

4.8

 

 

$

6,109

 
Montrose Amended and Restated 2013 Stock Option Plan  
Summary of Stock Option Activity The following summarizes the activity of the 2013 Plan for the years ended December 31, 2025, 2024 and 2023:

 

 

Options to Purchase Common Stock

 

 

Weighted-Average Exercise Price per Share

 

 

Weighted-Average Grant Date Fair Value per Share

 

 

Weighted-Average Remaining Contract Life (in Years)

 

 

Aggregate Intrinsic Value of In-The-Money Options

 

Outstanding as of December 31, 2022

 

855,695

 

 

$

6.00

 

 

$

2.10

 

 

 

3.3

 

 

$

32,478

 

Expired

 

(800

)

 

 

6.03

 

 

 

—

 

 

 

—

 

 

 

—

 

Exercised

 

(62,704

)

 

 

6.82

 

 

 

—

 

 

 

—

 

 

 

1,950

 

Outstanding as of December 31, 2023

 

792,191

 

 

$

6.40

 

 

$

2.16

 

 

 

2.4

 

 

$

20,380

 

Exercised

 

(111,302

)

 

 

5.87

 

 

 

—

 

 

 

—

 

 

 

3,042

 

Outstanding as of December 31, 2024

 

680,889

 

 

$

6.49

 

 

$

2.51

 

 

 

1.5

 

 

$

8,211

 

Expired

 

(3,500

)

 

 

6.03

 

 

 

—

 

 

 

—

 

 

 

—

 

Exercised

 

(109,562

)

 

 

6.40

 

 

 

—

 

 

 

—

 

 

 

1,991

 

Outstanding as of December 31, 2025

 

567,827

 

 

$

6.51

 

 

$

2.51

 

 

 

0.5

 

 

$

10,401

 

Exercisable as of December 31, 2025

 

567,827

 

 

$

6.51

 

 

 

 

 

 

0.5

 

 

$

10,401

 
v3.25.4
Net Loss Per Share (Tables)
 12 Months Ended
Dec. 31, 2025
Earnings Per Share [Abstract]  
Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders

The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company:

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

Net loss

 

$

(843

)

 

$

(62,314

)

 

$

(30,859

)

Convertible and Redeemable Series A-2 Preferred Stock dividend

 

 

(4,150

)

 

 

(11,064

)

 

 

(16,400

)

Net loss attributable to common stockholders – basic and diluted

 

 

(4,993

)

 

 

(73,378

)

 

 

(47,259

)

Weighted-average number of shares of common stock outstanding – basic and diluted

 

 

35,120

 

 

 

33,061

 

 

 

30,058

 

Net loss per share attributable to common stockholders – basic and diluted

 

$

(0.14

)

 

$

(2.22

)

 

$

(1.57

)
Common Stock Equivalents Excluded from Calculation of Diluted Net Income (Loss) Per Share Attributable to Common Stockholders

The following common stock equivalents were excluded from the calculation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive for the years ended December 31:

 

 

 

December 31,

 

 

 

2025(1)

 

 

2024(1)

 

 

2023(1)

 

Stock options

 

 

2,959,850

 

 

 

3,026,096

 

 

 

3,308,463

 

Restricted stock

 

 

2,324,404

 

 

 

2,617,059

 

 

 

2,468,722

 

Series A-2 Preferred Stock

 

 

2,654,739

 

 

 

4,293,793

 

 

 

5,952,609

 

SARs(2)

 

 

—

 

 

 

—

 

 

 

3,000,000

 

 

(1)
Includes 2,116,319, 2,374,716 and 7,660,169 shares underlying equity awards that were out of the money as of December 31, 2025, 2024 and 2023, respectively.
(2)
Effective December 31, 2024, the Board of Directors approved the SAR Cancellation (Note 17).
v3.25.4
Segment Information and Geographic Location Information (Tables)
 12 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Components of Segment Revenues, Segment Expenses and Segment Adjusted EBITDA

Segment Revenues, Segment Expenses and Segment Adjusted EBITDA were as follows:

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

(in thousands)

 

Segment Revenues

 

 

Segment Expenses

 

 

Segment Adjusted EBITDA

 

 

Segment Revenues

 

 

Segment Expenses

 

 

Segment Adjusted EBITDA

 

 

Segment Revenues

 

 

Segment Expenses

 

 

Segment Adjusted EBITDA

 

Assessment, Permitting and Response

 

$

307,428

 

 

$

238,973

 

 

$

68,455

 

 

$

214,850

 

 

$

166,830

 

 

$

48,020

 

 

$

220,727

 

 

$

168,579

 

 

$

52,148

 

Measurement and Analysis(1)

 

 

245,860

 

 

 

181,509

 

 

 

64,351

 

 

 

224,366

 

 

 

173,845

 

 

 

50,521

 

 

 

197,095

 

 

 

159,878

 

 

 

37,217

 

Remediation and Reuse

 

 

277,250

 

 

 

240,972

 

 

 

36,278

 

 

 

257,179

 

 

 

218,840

 

 

 

38,339

 

 

 

206,386

 

 

 

179,299

 

 

 

27,087

 

Total Reportable Segments

 

$

830,538

 

 

 

 

 

$

169,084

 

 

$

696,395

 

 

 

 

 

$

136,880

 

 

$

624,208

 

 

 

 

 

$

116,452

 

 

(1)
Includes revenue of $8.8 million and Adjusted EBITDA of $2.1 million from the Discontinued Specialty Lab for the year ended December 31, 2023. The lab was discontinued in the year ended December 31, 2023.
Reconciliation of Segment Measure to Income (Loss) Before Expense from Income Taxes

Presented below is a reconciliation of the Company’s segment measure to income (loss) before expense from income taxes for the years ended December 31:

 

 

 

For the Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

Total Reportable Segments

 

$

169,084

 

 

$

136,880

 

 

$

116,452

 

Corporate and Other

 

 

(52,920

)

 

 

(41,092

)

 

 

(37,876

)

Interest expense, net

 

 

(19,567

)

 

 

(15,862

)

 

 

(7,793

)

Depreciation and amortization

 

 

(50,915

)

 

 

(52,762

)

 

 

(45,780

)

Stock-based compensation

 

 

(42,716

)

 

 

(64,665

)

 

 

(47,267

)

Acquisition costs(1)

 

 

(1,825

)

 

 

(7,827

)

 

 

(6,930

)

Fair value changes in financial instruments

 

 

18,251

 

 

 

(3,124

)

 

 

4,129

 

Fair value changes in business acquisition contingencies

 

 

(900

)

 

 

(534

)

 

 

(84

)

Expenses related to financing transactions

 

 

(163

)

 

 

(317

)

 

 

(35

)

Discontinued Specialty Lab(2)

 

 

—

 

 

 

(692

)

 

 

(6,112

)

Business line restructuring costs(3)

 

 

(2,633

)

 

 

(146

)

 

 

(9

)

Other losses or expenses(4)

 

 

(4,475

)

 

 

(4,177

)

 

 

(534

)

Income (loss) before expense from income taxes

 

$

11,221

 

 

$

(54,318

)

 

$

(31,839

)

 

(1)
Includes financial and tax diligence, consulting, legal, valuation, accounting, travel and acquisition-related incentives related to our acquisition and integration activity.
(2)
Amounts consist of operating losses before depreciation related to the Discontinued Specialty Lab.
(3)
Amounts consist of severance costs related to organizational restructuring of business lines within the Company's Assessment, Permitting and Response and Remediation and Reuse segments, including costs incurred to wind down its renewable energy business.
(4)
The year ended December 31, 2025 consists primarily of losses and costs associated with exiting operations in Europe, nonrecurring rebranding expenses, and third party expenses associated with the independent review and analysis of assertions in a short seller report regarding the Company. The year ended December 31, 2024 consists primarily of non-recurring costs to centralize certain back-office functions, lease abandonment costs, and third party expenses associated with the independent review and analysis of assertions in a short seller report regarding the Company. The year ended December 31, 2023 consists primarily of expenses related to an aircraft accident, net of insurance gain, as well as a gain on the surrender of a lease.
Schedule of Revenues by Geographic Location

The following table presents revenues by geographic location:

 

 

 

For the Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

United States

 

$

678,382

 

 

$

550,323

 

 

$

539,578

 

Canada

 

 

120,762

 

 

 

115,918

 

 

 

72,608

 

Other international

 

 

31,394

 

 

 

30,154

 

 

 

12,022

 

Total revenue

 

$

830,538

 

 

$

696,395

 

 

$

624,208

 

 
Schedule of Long-lived Assets by Geographic Location

The following table presents long-lived assets by geographic location:

 

 

 

For the Year Ended December 31,

 

 

 

2025

 

 

2024

 

United States

 

$

58,590

 

 

$

57,730

 

Canada

 

 

4,311

 

 

 

5,070

 

Other international

 

 

952

 

 

 

976

 

Total property and equipment—net

 

$

63,853

 

 

$

63,776

 
v3.25.4
Description of the Business and Basis of Presentation - Additional Information (Details)
 12 Months Ended
Dec. 31, 2025
Employee
Office
Segment
Description Of Business And Basis Of Presentation [Line Items]  
Entity formation, month and year 2013-11
Number of offices in which entity operates | Office 120
Entity number of employees | Employee 3,500
Number of operating segments 3
Number of reportable segments 3
v3.25.4
Significant Accounting Policies - Additional Information (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2025
USD ($)
Segment
Dec. 31, 2024
USD ($)
Significant Accounting Policies [Line Items]    
Restricted cash | $ $ 0.2 $ 1.5
Number of reportable segments | Segment 3  
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration] srt:ChiefExecutiveOfficerMember  
v3.25.4
Summary of New Accounting Pronouncements - Additional Information (Details)
 12 Months Ended
Dec. 31, 2025
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]  
Accounting Standards Update [Extensible Enumeration] Accounting Standards Update 2023-05
Accounting Standards Update 2023-05  
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]  
Change in accounting principle, accounting standards update, adopted true
Change in accounting principle, accounting standards update, adoption date Jan. 01, 2025
Change in accounting principle, accounting standards update, immaterial effect false
Accounting Standards Update 2023-09  
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]  
Change in accounting principle, accounting standards update, adopted true
Change in accounting principle, accounting standards update, adoption date Jan. 01, 2025
Change in accounting principle, accounting standards update, immaterial effect false
v3.25.4
Revenues and Accounts Receivable - Schedule of Contract Balances (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Revenues And Accounts Receivable [Abstract]    
Contract assets $ 58,831 $ 52,091
Contract liabilities $ 14,996 $ 9,297
v3.25.4
Revenues and Accounts Receivable - Additional Information (Details)
 12 Months Ended
Dec. 31, 2025
USD ($)
Customer
Dec. 31, 2024
USD ($)
Customer
Dec. 31, 2023
Customer
Accounts Notes And Loans Receivable [Line Items]      
Contracts assets acquired through business acquisitions $ 0 $ 2,600,000  
Contract liabilities acquired through business acquisitions 0 0  
Contract with customer liabilities, revenue recognized 6,000,000    
Revenue remaining performance obligations 68,400,000 $ 77,300,000  
Receivables sold 13,400,000    
Significant Customer      
Accounts Notes And Loans Receivable [Line Items]      
Revenue from customer included in emergency and non-emergency response revenue $ 112,200,000    
Customer Concentration Risk | Revenue | Significant Customer      
Accounts Notes And Loans Receivable [Line Items]      
Concentration risk percentage 17.80% 10.00% 10.00%
Number of customers | Customer 1 0 1
Customer Concentration Risk | Accounts Receivable | Significant Customer      
Accounts Notes And Loans Receivable [Line Items]      
Concentration risk percentage 10.00% 10.00%  
Number of customers | Customer 1 0  
v3.25.4
Revenues and Accounts Receivable - Additional Information (Details1)
Dec. 31, 2025
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2025-01-01  
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]  
Revenue remaining performance obligations, percentage 82.00%
Revenue remaining performance obligations, satisfaction period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2026-01-01  
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]  
Revenue remaining performance obligations, percentage 18.00%
Revenue remaining performance obligations, satisfaction period 1 year
v3.25.4
Revenues and Accounts Receivable - Schedule of Accounts Receivable, Net (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Revenues And Accounts Receivable [Abstract]        
Accounts receivable, invoiced $ 163,694 $ 160,976    
Allowance for doubtful accounts (8,314) (2,093) $ (2,724) $ (1,915)
Accounts receivable, net $ 155,380 $ 158,883    
v3.25.4
Revenues and Accounts Receivable - Schedule of Allowance for Doubtful Accounts (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Revenues And Accounts Receivable [Abstract]      
Beginning Balance $ 2,093 $ 2,724 $ 1,915
Bad Debt Expense (Recovery) 6,713 (146) 3,142 [1]
Charged to Allowance (492) (485) (2,333) [1]
Ending Balance $ 8,314 $ 2,093 $ 2,724
[1] Amount includes $2.2 million of current expected losses on the Discontinued Specialty Lab promissory note receivable as described in Note 8.
v3.25.4
Revenues and Accounts Receivable - Schedule of Allowance for Doubtful Accounts (Parenthetical) (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2025
USD ($)
Discontinuing Specialty Lab  
Accounts, Notes, Loans and Financing Receivable [Line Items]  
Promissory note receivable, current expected losses $ 2.2
v3.25.4
Prepaid and Other Current Assets - Schedule of Prepaid and Other Current Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]    
Deposits $ 967 $ 1,073
Prepaid expenses 11,367 10,223
Supplies 2,625 2,794
Prepaid and other current assets $ 14,959 $ 14,090
v3.25.4
Property and Equipment, Net - Property and Equipment, Net (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Property Plant And Equipment [Line Items]    
Property and equipment, gross $ 140,809 $ 126,943
Less: Accumulated depreciation (79,975) (68,249)
Total property and equipment—net $ 63,853 63,776
Lab and test equipment    
Property Plant And Equipment [Line Items]    
Estimated Useful Life 7 years  
Property and equipment, gross $ 24,604 24,421
Vehicles    
Property Plant And Equipment [Line Items]    
Estimated Useful Life 5 years  
Property and equipment, gross $ 6,696 6,360
Equipment    
Property Plant And Equipment [Line Items]    
Property and equipment, gross $ 70,702 60,763
Equipment | Minimum    
Property Plant And Equipment [Line Items]    
Estimated Useful Life 3 years  
Equipment | Maximum    
Property Plant And Equipment [Line Items]    
Estimated Useful Life 7 years  
Furniture and fixtures    
Property Plant And Equipment [Line Items]    
Estimated Useful Life 7 years  
Property and equipment, gross $ 5,322 3,221
Leasehold improvements    
Property Plant And Equipment [Line Items]    
Estimated Useful Life 7 years  
Property and equipment, gross $ 15,335 14,029
Aircraft    
Property Plant And Equipment [Line Items]    
Property and equipment, gross $ 12,386 12,386
Aircraft | Minimum    
Property Plant And Equipment [Line Items]    
Estimated Useful Life 10 years  
Aircraft | Maximum    
Property Plant And Equipment [Line Items]    
Estimated Useful Life 20 years  
Building    
Property Plant And Equipment [Line Items]    
Estimated Useful Life 20 years  
Property and equipment, gross $ 5,764 5,763
Land    
Property Plant And Equipment [Line Items]    
Property and equipment, gross 1,089 1,089
Construction in Progress    
Property Plant And Equipment [Line Items]    
Property and equipment, gross $ 1,930 $ 3,993
v3.25.4
Property and Equipment, Net - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Property Plant And Equipment [Line Items]      
Depreciation expense $ 12.3 $ 12.0 $ 10.3
v3.25.4
Leases - Additional Information (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2025
USD ($)
Equipment Line Of Credit  
Lessee Lease Description [Line Items]  
Line of credit, outstanding balance $ 16.1
Minimum  
Lessee Lease Description [Line Items]  
Lessee operating and finance lease term 1 year
Maximum  
Lessee Lease Description [Line Items]  
Lessee operating and finance lease term 20 years
v3.25.4
Leases - Summary of Components of Lease Expense (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Lessee Lease Description [Line Items]    
Total operating lease cost $ 15,547 $ 15,884
Total finance lease cost 9,926 6,425
Total lease cost 25,473 22,309
Selling, General and Administrative Expenses    
Lessee Lease Description [Line Items]    
Lease cost 12,511 13,667
Variable lease cost 3,036 2,217
Depreciation and Amortization    
Lessee Lease Description [Line Items]    
Amortization of ROU assets 8,694 5,814
Interest Expense, Net    
Lessee Lease Description [Line Items]    
Interest on lease liabilities $ 1,232 $ 611
v3.25.4
Leases - Summary of Supplemental Cash Flow Information Related To Leases (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Leases [Abstract]    
Operating cash flows used in operating leases $ 13,777 $ 13,202
Operating cash flows used for interest related to finance leases 1,256 661
Financing cash flows used in finance leases 6,368 5,489
Operating leases 9,204 20,951
Finance leases $ 22,133 $ 8,841
v3.25.4
Leases - Summary of Weighted Average Remaining Lease Terms and Weighted Average Discount Rates (Details)
Dec. 31, 2025
Dec. 31, 2024
Leases [Abstract]    
Weighted average remaining lease term, Operating Leases 4 years 10 months 24 days 4 years 7 months 6 days
Weighted average remaining lease term, Finance Leases 9 years 8 months 12 days 3 years 8 months 12 days
Weighted average discount rate, Operating Leases 5.10% 4.80%
Weighted average discount rate, Finance Leases 6.70% 6.70%
v3.25.4
Leases - Summary of Maturities of Lease Liabilities (Details)
$ in Thousands
Dec. 31, 2025
USD ($)
Leases [Abstract]  
Operating Leases, 2026 $ 12,394
Operating Leases, 2027 9,542
Operating Leases, 2028 7,868
Operating Leases, 2029 6,069
Operating Leases, 2030 2,839
Operating Leases, 2031 and thereafter 5,865
Operating Leases, Total undiscounted future minimum lease payments 44,577
Operating Leases, Less imputed interest (5,627)
Operating Leases, Total discounted future minimum lease payments 38,950
Finance Leases, 2026 8,479
Finance Leases, 2027 7,070
Finance Leases, 2028 5,405
Finance Leases, 2029 3,749
Finance Leases, 2030 1,947
Finance Leases, 2031 and thereafter 18,882
Finance Leases, Total undiscounted future minimum lease payments 45,532
Finance Leases, Less imputed interest (13,750)
Finance Leases, Total discounted future minimum lease payments $ 31,782
v3.25.4
Business Acquisitions and Dispositions - Additional Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 29, 2023
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Jul. 31, 2024
May 31, 2024
Feb. 29, 2024
Jan. 31, 2024
Jul. 31, 2023
Jun. 30, 2023
May 31, 2023
Feb. 28, 2023
Business Acquisition [Line Items]                        
Transaction costs related to business combinations [1]   $ 1,825 $ 7,827 $ 6,930                
Business combination, paid in cash     115,121 68,640                
Common Stock     10,712 2,598                
Discontinuing Specialty Lab                        
Business Acquisition [Line Items]                        
Sales price of assets $ 4,800                      
Cash received 500                      
Promissory note receivable 4,300                      
Discontinuing Specialty Lab | Selling, General and Administrative Expenses                        
Business Acquisition [Line Items]                        
Gain on sale of assets 1,800                      
Promissory note receivable, current expected losses $ 2,200                      
EAI                        
Business Acquisition [Line Items]                        
Percentage of interests acquired                       100.00%
GreenPath                        
Business Acquisition [Line Items]                        
Percentage of interests acquired                     100.00%  
Matrix                        
Business Acquisition [Line Items]                        
Percentage of interests acquired                   100.00%    
Vandrensning                        
Business Acquisition [Line Items]                        
Percentage of interests acquired                 100.00%      
EnvStd and IAG | 2026 Earn Out                        
Business Acquisition [Line Items]                        
Business combination, earn-out payment, maximum   17,600                    
Business combination, paid in cash   5,100                    
Common Stock   2,800                    
Payment through cash or common stock   $ 9,700                    
EPIC, 2DOT, ETA, Paragon, Spirit and Origins                        
Business Acquisition [Line Items]                        
Revenue     44,600                  
Pre-tax income (loss)     8,500                  
Matrix, Frontier, EAI, GreenPath                        
Business Acquisition [Line Items]                        
Revenue       69,100                
Pre-tax income (loss)       $ 8,800                
Spirit                        
Business Acquisition [Line Items]                        
Percentage of interests acquired         100.00%              
Business combination, paid in cash     16,027                  
Common Stock     1,441                  
Paragon                        
Business Acquisition [Line Items]                        
Percentage of interests acquired           100.00%            
Business combination, paid in cash     10,773                  
Common Stock     2,691                  
EPIC                        
Business Acquisition [Line Items]                        
Percentage of interests acquired               100.00%        
Business combination, paid in cash     19,914                  
Common Stock     4,748                  
2DOT                        
Business Acquisition [Line Items]                        
Percentage of interests acquired             100.00%          
Business combination, paid in cash     39,393                  
Common Stock     $ 1,832                  
[1] Includes financial and tax diligence, consulting, legal, valuation, accounting, travel and acquisition-related incentives related to our acquisition and integration activity.
v3.25.4
Business Acquisitions and Dispositions - Weighted Average Useful Lives of Identifiable Intangible Assets (Details)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Business Acquisition [Line Items]    
Weighted average 5 years 3 months 18 days 4 years 8 months 12 days
Customer Relationships    
Business Acquisition [Line Items]    
Weighted average 8 years 2 months 12 days 9 years 4 months 24 days
Covenants Not to Compete    
Business Acquisition [Line Items]    
Weighted average 5 years 4 years 10 months 24 days
Trade Names    
Business Acquisition [Line Items]    
Weighted average 2 years 1 year 9 months 18 days
Proprietary Software    
Business Acquisition [Line Items]    
Weighted average   3 years
v3.25.4
Business Acquisitions and Dispositions - Summary of Final Elements of Purchase Price of Acquisitions (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Business Acquisition [Line Items]    
Cash $ 115,121 $ 68,640
Common Stock 10,712 2,598
Other Purchase Price Components 599 1,603
Contingent Consideration 29,421 1,096
Total Purchase Price 155,853 $ 73,937
EPIC    
Business Acquisition [Line Items]    
Cash 19,914  
Common Stock 4,748  
Other Purchase Price Components 419  
Contingent Consideration 11,113  
Total Purchase Price 36,194  
2DOT    
Business Acquisition [Line Items]    
Cash 39,393  
Common Stock 1,832  
Other Purchase Price Components (660)  
Contingent Consideration 0  
Total Purchase Price 40,565  
ETA    
Business Acquisition [Line Items]    
Cash 1,600  
Common Stock 0  
Other Purchase Price Components 400  
Contingent Consideration 0  
Total Purchase Price 2,000  
Paragon    
Business Acquisition [Line Items]    
Cash 10,773  
Common Stock 2,691  
Other Purchase Price Components 125  
Contingent Consideration 0  
Total Purchase Price 13,589  
Spirit    
Business Acquisition [Line Items]    
Cash 16,027  
Common Stock 1,441  
Other Purchase Price Components 95  
Contingent Consideration 10,308  
Total Purchase Price 27,871  
Origins    
Business Acquisition [Line Items]    
Cash 27,414  
Common Stock 0  
Other Purchase Price Components 220  
Contingent Consideration 8,000  
Total Purchase Price $ 35,634  
v3.25.4
Business Acquisitions and Dispositions - Summary of Final Purchase Price Attributable to Acquisitions (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Business Acquisition [Line Items]      
Cash $ 2,035    
Accounts receivable and contract assets 8,093    
Other current assets 282    
Current assets 10,410    
Property and equipment 2,316    
Operating lease right-of-use asset 3,624    
Goodwill 107,154    
Total assets 167,956    
Current liabilities 5,460    
Deferred tax liability 4,214    
Operating lease liability—net of current portion 2,258    
Other non-current liabilities 171    
Total liabilities 12,103    
Purchase price 155,853    
Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets 37,178    
Trade Names      
Business Acquisition [Line Items]      
Intangible assets 1,685    
Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets 5,589    
2023 Acquisitions      
Business Acquisition [Line Items]      
Cash   $ 2,453 $ 2,453
Accounts receivable and contract assets   19,174 19,174
Other current assets   2,185 2,185
Current assets   23,812 23,812
Property and equipment   3,936 3,936
Operating lease right-of-use asset   4,825 4,825
Other intangible assets   444 444
Goodwill   39,920 40,786
Total assets   97,980 98,846
Current liabilities   11,557 11,557
Deferred tax liability   1,999 1,999
Operating lease liability—net of current portion   10,357 10,357
Other non-current liabilities   130 130
Total liabilities   24,043 24,043
Purchase price   73,937 74,803
Measurement Period Adjustments      
Goodwill   (866)  
Total assets   (866)  
Purchase price   (866)  
2023 Acquisitions | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets   19,962 19,962
2023 Acquisitions | Trade Names      
Business Acquisition [Line Items]      
Intangible assets   2,373 2,373
2023 Acquisitions | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets   2,708 $ 2,708
EPIC      
Business Acquisition [Line Items]      
Cash 1,045    
Accounts receivable and contract assets 1,772    
Other current assets 78    
Current assets 2,895    
Property and equipment 43    
Operating lease right-of-use asset 280    
Goodwill 24,934    
Total assets 42,545    
Current liabilities 1,994    
Deferred tax liability 4,214    
Operating lease liability—net of current portion 0    
Other non-current liabilities 143    
Total liabilities 6,351    
Purchase price 36,194    
EPIC | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets 12,053    
EPIC | Trade Names      
Business Acquisition [Line Items]      
Intangible assets 523    
EPIC | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets 1,817    
EPIC | Initially Reported      
Business Acquisition [Line Items]      
Cash   1,045  
Accounts receivable and contract assets   1,772  
Other current assets   78  
Current assets   2,895  
Property and equipment   43  
Operating lease right-of-use asset   280  
Goodwill   25,102  
Total assets   42,713  
Current liabilities   1,994  
Deferred tax liability   4,214  
Operating lease liability—net of current portion   0  
Other non-current liabilities   143  
Total liabilities   6,351  
Purchase price   36,362  
EPIC | Initially Reported | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets   12,053  
EPIC | Initially Reported | Trade Names      
Business Acquisition [Line Items]      
Intangible assets   523  
EPIC | Initially Reported | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets   1,817  
EPIC | Period Adjustments      
Measurement Period Adjustments      
Goodwill (168)    
Total assets (168)    
Purchase price (168)    
2DOT      
Business Acquisition [Line Items]      
Cash 143    
Accounts receivable and contract assets 740    
Other current assets 0    
Current assets 883    
Property and equipment 0    
Operating lease right-of-use asset 301    
Goodwill 27,317    
Total assets 41,162    
Current liabilities 404    
Deferred tax liability 0    
Operating lease liability—net of current portion 193    
Other non-current liabilities 0    
Total liabilities 597    
Purchase price 40,565    
2DOT | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets 9,521    
2DOT | Trade Names      
Business Acquisition [Line Items]      
Intangible assets 200    
2DOT | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets 2,940    
2DOT | Initially Reported      
Business Acquisition [Line Items]      
Cash   143  
Accounts receivable and contract assets   740  
Other current assets   0  
Current assets   883  
Property and equipment   0  
Operating lease right-of-use asset   301  
Goodwill   27,273  
Total assets   41,118  
Current liabilities   404  
Deferred tax liability   0  
Operating lease liability—net of current portion   193  
Other non-current liabilities   0  
Total liabilities   597  
Purchase price   40,521  
2DOT | Initially Reported | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets   9,521  
2DOT | Initially Reported | Trade Names      
Business Acquisition [Line Items]      
Intangible assets   200  
2DOT | Initially Reported | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets   2,940  
2DOT | Period Adjustments      
Measurement Period Adjustments      
Goodwill 44    
Total assets 44    
Purchase price 44    
ETA      
Business Acquisition [Line Items]      
Cash 0    
Accounts receivable and contract assets 0    
Other current assets 0    
Current assets 0    
Property and equipment 0    
Operating lease right-of-use asset 0    
Goodwill 2,000    
Total assets 2,000    
Current liabilities 0    
Deferred tax liability 0    
Operating lease liability—net of current portion 0    
Other non-current liabilities 0    
Total liabilities 0    
Purchase price 2,000    
ETA | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets 0    
ETA | Trade Names      
Business Acquisition [Line Items]      
Intangible assets 0    
ETA | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets 0    
Paragon      
Business Acquisition [Line Items]      
Cash 242    
Accounts receivable and contract assets 3,188    
Other current assets 85    
Current assets 3,515    
Property and equipment 341    
Operating lease right-of-use asset 1,798    
Goodwill 6,444    
Total assets 16,702    
Current liabilities 1,572    
Deferred tax liability 0    
Operating lease liability—net of current portion 1,513    
Other non-current liabilities 28    
Total liabilities 3,113    
Purchase price 13,589    
Paragon | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets 4,209    
Paragon | Trade Names      
Business Acquisition [Line Items]      
Intangible assets 350    
Paragon | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets 45    
Spirit      
Business Acquisition [Line Items]      
Cash 605    
Accounts receivable and contract assets 2,393    
Other current assets 119    
Current assets 3,117    
Property and equipment 145    
Operating lease right-of-use asset 693    
Goodwill 20,336    
Total assets 29,361    
Current liabilities 1,490    
Deferred tax liability 0    
Operating lease liability—net of current portion 0    
Other non-current liabilities 0    
Total liabilities 1,490    
Purchase price 27,871    
Spirit | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets 4,090    
Spirit | Trade Names      
Business Acquisition [Line Items]      
Intangible assets 280    
Spirit | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets 700    
Spirit | Initially Reported      
Business Acquisition [Line Items]      
Cash   605  
Accounts receivable and contract assets   2,393  
Other current assets   119  
Current assets   3,117  
Property and equipment   145  
Operating lease right-of-use asset   693  
Goodwill   18,285  
Total assets   27,310  
Current liabilities   1,490  
Deferred tax liability   0  
Operating lease liability—net of current portion   0  
Other non-current liabilities   0  
Total liabilities   1,490  
Purchase price   25,820  
Spirit | Initially Reported | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets   4,090  
Spirit | Initially Reported | Trade Names      
Business Acquisition [Line Items]      
Intangible assets   280  
Spirit | Initially Reported | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets   700  
Spirit | Period Adjustments      
Measurement Period Adjustments      
Goodwill 2,051    
Total assets 2,051    
Purchase price 2,051    
Origins      
Business Acquisition [Line Items]      
Cash 0    
Accounts receivable and contract assets 0    
Other current assets 0    
Current assets 0    
Property and equipment 1,787    
Operating lease right-of-use asset 552    
Goodwill 26,123    
Total assets 36,186    
Current liabilities 0    
Deferred tax liability 0    
Operating lease liability—net of current portion 552    
Other non-current liabilities 0    
Total liabilities 552    
Purchase price 35,634    
Origins | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets 7,305    
Origins | Trade Names      
Business Acquisition [Line Items]      
Intangible assets 332    
Origins | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets 87    
Origins | Initially Reported      
Business Acquisition [Line Items]      
Cash   0  
Accounts receivable and contract assets   0  
Other current assets   0  
Current assets   0  
Property and equipment   1,787  
Operating lease right-of-use asset   552  
Goodwill   25,903  
Total assets   35,966  
Current liabilities   0  
Deferred tax liability   0  
Operating lease liability—net of current portion   552  
Other non-current liabilities   0  
Total liabilities   552  
Purchase price   35,414  
Origins | Initially Reported | Customer Relationships      
Business Acquisition [Line Items]      
Intangible assets   7,305  
Origins | Initially Reported | Trade Names      
Business Acquisition [Line Items]      
Intangible assets   332  
Origins | Initially Reported | Covenants Not to Compete      
Business Acquisition [Line Items]      
Intangible assets   $ 87  
Origins | Period Adjustments      
Measurement Period Adjustments      
Goodwill 220    
Total assets 220    
Purchase price $ 220    
v3.25.4
Business Acquisitions and Dispositions - Summary of Supplemental Unaudited Pro-Forma Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Business Combination [Line Items]      
Revenues $ 830,538 $ 696,395 $ 624,208
Net (loss) (843) (62,314) (30,859)
Acquisition Proforma      
Business Combination [Line Items]      
Revenues 0 24,559 65,798
Net (loss) income 0 9,413 8,110
Consolidated Proforma      
Business Combination [Line Items]      
Revenues 830,538 720,954 690,006
Net (loss) income $ (843) $ (52,901) $ (22,749)
v3.25.4
Goodwill and Intangible Assets - Schedule of Amounts Related to Goodwill (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
Goodwill [Line Items]  
Beginning balance $ 467,789
Acquisitions measurement period adjustments, net of foreign currency translation 1,641
Goodwill disposed during the period (2,644) [1]
Ending balance 466,786
Assessment, Permitting and Response  
Goodwill [Line Items]  
Beginning balance 205,231
Acquisitions measurement period adjustments, net of foreign currency translation 1,501
Ending balance 206,732
Measurement and Analysis  
Goodwill [Line Items]  
Beginning balance 118,860
Acquisitions measurement period adjustments, net of foreign currency translation 220
Ending balance 119,080
Remediation and Reuse Segment  
Goodwill [Line Items]  
Beginning balance 143,698
Acquisitions measurement period adjustments, net of foreign currency translation (80)
Goodwill disposed during the period (2,644) [1]
Ending balance $ 140,974
[1] Goodwill disposed during the period is due to the disposition of the Company's business in Denmark
v3.25.4
Goodwill and Intangible Assets - Schedule of Amounts Related to Finite-Lived Intangible Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Finite-Lived Intangible Assets [Line Items]    
Gross Balance $ 381,360 $ 378,081
Accumulated Amortization 254,977 225,325
Total Intangible Assets—Net 126,383 152,756
Customer Relationships    
Finite-Lived Intangible Assets [Line Items]    
Gross Balance 264,564 264,477
Accumulated Amortization 160,459 138,787
Total Intangible Assets—Net $ 104,105 $ 125,690
Customer Relationships | Minimum    
Finite-Lived Intangible Assets [Line Items]    
Estimated Useful Life 2 years 2 years
Customer Relationships | Maximum    
Finite-Lived Intangible Assets [Line Items]    
Estimated Useful Life 15 years 15 years
Covenants Not to Compete    
Finite-Lived Intangible Assets [Line Items]    
Gross Balance $ 41,418 $ 41,758
Accumulated Amortization 36,293 33,898
Total Intangible Assets—Net $ 5,125 $ 7,860
Covenants Not to Compete | Minimum    
Finite-Lived Intangible Assets [Line Items]    
Estimated Useful Life 4 years 4 years
Covenants Not to Compete | Maximum    
Finite-Lived Intangible Assets [Line Items]    
Estimated Useful Life 5 years 5 years
Trade Names    
Finite-Lived Intangible Assets [Line Items]    
Gross Balance $ 25,917 $ 25,939
Accumulated Amortization 25,441 23,375
Total Intangible Assets—Net $ 476 $ 2,564
Trade Names | Minimum    
Finite-Lived Intangible Assets [Line Items]    
Estimated Useful Life 1 year 1 year
Trade Names | Maximum    
Finite-Lived Intangible Assets [Line Items]    
Estimated Useful Life 5 years 5 years
Proprietary Software    
Finite-Lived Intangible Assets [Line Items]    
Gross Balance $ 31,982 $ 28,428
Accumulated Amortization 25,912 23,489
Total Intangible Assets—Net $ 6,070 $ 4,939
Proprietary Software | Minimum    
Finite-Lived Intangible Assets [Line Items]    
Estimated Useful Life 3 years 3 years
Proprietary Software | Maximum    
Finite-Lived Intangible Assets [Line Items]    
Estimated Useful Life 5 years 5 years
Patent    
Finite-Lived Intangible Assets [Line Items]    
Estimated Useful Life 16 years 16 years
Gross Balance $ 17,479 $ 17,479
Accumulated Amortization 6,872 5,776
Total Intangible Assets—Net $ 10,607 $ 11,703
v3.25.4
Goodwill and Intangible Assets - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]      
Amortization expense $ 29.9 $ 34.9 $ 30.1
v3.25.4
Goodwill and Intangible Assets - Schedule of Future Amortization Expense (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]    
2026 $ 25,371  
2027 24,258  
2028 18,664  
2029 12,773  
2030 9,418  
Thereafter 35,899  
Total Intangible Assets—Net $ 126,383 $ 152,756
v3.25.4
Accounts Payable and Other Accrued Liabilities - Summary of Accounts Payable and Other Accrued Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Payables and Accruals [Abstract]    
Accounts payable $ 34,806 $ 33,424
Accrued expenses 18,373 16,190
Contract liabilities 14,996 9,297
Other current liabilities 3,603 4,793
Total accounts payable and other accrued liabilities $ 71,778 $ 63,704
v3.25.4
Accrued Payroll and Benefits - Schedule of Accrued Payroll and Benefits (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Statement of Financial Position [Abstract]    
Accrued bonuses $ 28,568 $ 14,433
Accrued payroll 13,501 11,969
Accrued paid time off 3,603 4,214
Accrued medical 2,305 1,589
Accrued other 4,796 2,043
Total accrued payroll and benefits $ 52,773 $ 34,248
v3.25.4
Income Taxes - Summary of Geographical Breakdown of Income (Loss) Before Provision for Income (Loss) Taxes (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income Tax Disclosure [Abstract]      
Federal $ 17,189 $ (54,860) $ (35,111)
Foreign (5,968) 542 3,272
Income (loss) before expense from income taxes $ 11,221 $ (54,318) $ (31,839)
v3.25.4
Income Taxes - Summary of Income Tax Expense (Benefit) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Current:      
Federal $ 29 $ 244  
State 2,271 817 $ 1,840
Foreign 1,081 1,887 (1,131)
Total current tax expense 3,381 2,948 709
Deferred:      
Federal 10,053 1,160 (438)
State (452) 1,850 (960)
Foreign (918) 2,038 (291)
Total deferred tax expense 8,683 5,048 (1,689)
Federal 10,082 1,404 (438)
State 1,819 2,667 880
Foreign 163 3,925 (1,422)
Income tax expense (benefit) $ 12,064 $ 7,996 $ (980)
v3.25.4
Income Taxes - Schedule of Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Deferred tax assets:    
Net operating losses $ 11,000 $ 14,021
Section 163(j) interest limitation 3,058 7,627
Equity compensation 2,063 7,669
Contingent consideration 8,621 9,007
Lease liabilities 17,182 (15,274)
Accrued compensation 6,991 4,117
Transaction costs 2,384 2,525
Section 174 Research & Experimental 648 1,312
Interest rate swap 106 (402)
Other 8,067 6,593
Total deferred tax asset 60,120 37,195
Deferred tax liabilities:    
Intangible assets (24,650) (22,399)
Property and equipment (14,104) (13,944)
ROU assets (18,027) 14,986
Other (90) (1,529)
Total deferred tax liability (56,871) (22,886)
Valuation allowance (25,066) (27,621)
Net deferred tax liability $ (21,817) $ (13,312)
v3.25.4
Income Taxes - Effective Tax Rate of Company's Provision (Benefit) for Income Taxes Differs from Federal Statutory Rate (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Effective Income Tax Rate Reconciliation [Line Items]      
US federal statutory tax rate $ 2,356 $ (11,408) $ (6,686)
US federal statutory tax rate, percent 21.00% 21.00% 21.00%
State and local income taxes, net of federal income tax effect [1] $ 1,150 $ 2,511 $ 477
State and local income taxes, net of federal income tax effect, percent [1] 10.25% (4.62%) (1.50%)
Global intangible low-taxed income $ 316 $ 1,410 $ 1,067
Global intangible low-taxed income, percent 2.81% (2.60%) (3.35%)
US tax impact of foreign branches $ (174) $ (501) $ (148)
US tax impact of foreign branches, percent (1.55%) 0.92% 0.47%
Sale of Denmark business $ 566 $ 0 $ 0
Sale of Denmark business, percent 5.05% 0.00% 0.00%
Federal research and development credit $ (1,139) $ 0 $ 0
Federal research and development credit, percent (10.15%) 0.00% 0.00%
Change in valuation allowance $ 157 $ (911) $ (4,421)
Change in valuation allowance, percent 1.40% 1.68% 13.88%
Equity compensation $ 7,636 $ 1,519 $ 539
Equity compensation, percent 68.06% (2.80%) (1.69%)
Mark to market - fair value derivative $ (4,247) $ 253 $ (1,410)
Mark to market - fair value derivative, percent (37.85%) (0.47%) 4.43%
Meals $ 365 $ 365 $ 526
Meals, percent 3.25% (0.67%) (1.65%)
Transaction expense - deemed contribution to controlled foreign corporation $ 0 $ 318 $ 492
Transaction expense - deemed contribution to controlled foreign corporation, percent 0.00% (0.59%) (1.55%)
Worldwide changes in unrecognized tax benefits $ 624 $ 0 $ 0
Worldwide changes in unrecognized tax benefits, percent 5.56% 0.00% 0.00%
Federal deferred tax adjustments $ 1,346 $ 10,659 $ 9,606
Federal deferred tax adjustment, percent 12.00% (19.62%) (30.17%)
Federal tax return true up $ 222 $ (940) $ 448
Federal tax return true-up, percent 1.98% 1.73% (1.41%)
Section 162(m) compensation deduction limitation $ 1,229 $ 183 $ 22
Section 162(m) compensation deduction limitation, percent 10.95% (0.34%) (0.07%)
Other $ 239 $ 725 $ 539
Other, percent 2.13% (1.34%) (1.69%)
Other foreign jurisdictions $ 440 $ 502 $ 406
Other foreign jurisdictions, percent 3.91% (0.63%) (1.02%)
Income tax expense (benefit) $ 12,064 $ 7,996 $ (980)
Effective income tax rate, percent 107.51% (14.45%) 3.33%
CANADA      
Effective Income Tax Rate Reconciliation [Line Items]      
Rate differential $ (203) $ 18 $ 153
Rate differential, percent (1.81%) (0.03%) (0.48%)
Return-to-provision adjustments $ 756 $ 2,953 $ (466)
Return-to-provision adjustments, percent 6.74% (5.44%) 1.46%
Impact of scientific research and experimental development credits $ (641) $ 269 $ (2,028)
Impact of scientific research and experimental development credits, percent (5.72%) (0.50%) 6.37%
Other $ 67 $ (101) $ 11
Other, percent 0.60% 0.19% (0.04%)
AUSTRALIA      
Effective Income Tax Rate Reconciliation [Line Items]      
Change in valuation allowance $ 0 $ 0 $ (153)
Change in valuation allowance, percent 0.00% 0.00% 0.48%
Rate differential $ 999 $ 172 $ 46
Rate differential, percent 8.90% (0.32%) (0.14%)
[1] In each year, the state and local income taxes which comprise the majority of the state and local income taxes, net of federal effect category are California and Pennsylvania.
v3.25.4
Income Taxes - Schedule of Cash Paid for Income Taxes (Net of Refund) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income Tax Paid, by Individual Jurisdiction [Line Items]      
Federal $ 540    
State and local 3,271 $ 2,274 $ 997
Foreign 1,694 1,920  
Total 5,505 4,194 997
Pennsylvania      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
State and local 213 307 614
Texas      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
State and local 200 219 (129)
Alabama      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
State and local 613 89 9
California      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
State and local 1,045 87 10
Other      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
State and local 1,200 1,572 $ 493
Canada      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
Foreign 195 1,232  
Australia      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
Foreign $ 1,499 $ 688  
v3.25.4
Income Taxes - Additional Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Income Tax Disclosure [Line Items]    
Increase (decrease) in valuation allowance $ (2,600) $ 3,500
Uncertain tax positions 623  
Recognize interest and penalties $ 0  
Income Tax Examination, Description The Company is subject to audit by federal and state tax authorities in the ordinary course of business. The Company’s federal income tax returns remain subject to examination generally for the 2022 taxable year through the current taxable year, except for certain prior taxable years with net operating loss carry forwards that will remain subject to examination until the expiration of the statute of limitations for the taxable years of utilization of such net operating losses. The Company files tax returns in multiple US state jurisdictions which remain subject to examination for various years depending on such state jurisdiction. The Company is also subject to audit by tax authorities in Canada, Australia, Germany, Sweden, Belgium, and Denmark for which returns are subject to examination for various years, dependent on the jurisdiction.  
Domestic Tax Authority [Member]    
Income Tax Disclosure [Line Items]    
Operating Loss Carryforwards $ 31,900  
Research and development credit carryforwards $ 800  
Tax years remain subject to examination 2022 2023 2024 2025  
State and Local Jurisdiction [Member]    
Income Tax Disclosure [Line Items]    
Operating Loss Carryforwards $ 94,200  
Research and development credit carryforwards $ 100  
v3.25.4
Income Taxes - Schedule of Unrecognized Tax Positions (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
Income Tax Uncertainties [Abstract]  
Increases related to prior year tax positions $ 334
Increases related to current year tax positions 289
Balance at end of the year $ 623
v3.25.4
Debt - Schedule of Debt (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Line Of Credit Facility [Line Items]    
Less deferred debt issuance costs $ (1,993) $ (997)
Total debt 288,295 222,684
Less current portion of long-term debt (11,230) (17,866)
Long-term debt, less current portion 277,065 204,818
Term Loan Facility    
Line Of Credit Facility [Line Items]    
Total debt 197,500 189,218
Revolving Line of Credit    
Line Of Credit Facility [Line Items]    
Total debt 84,663 25,191
Aircraft Loan    
Line Of Credit Facility [Line Items]    
Total debt $ 8,125 $ 9,272
v3.25.4
Debt - Additional Information (Details) - USD ($)
 12 Months Ended
Feb. 26, 2025
May 18, 2023
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Mar. 31, 2025
Line Of Credit Facility [Line Items]            
Amortization of deferred debt issuance cost     $ 1,400,000 $ 700,000 $ 500,000  
Consolidated total leverage ratio     250.00% 210.00%    
Deferred debt issuance cost     $ 1,993,000 $ 997,000    
Incremental Term Loans            
Line Of Credit Facility [Line Items]            
Line of credit facility, maximum borrowing capacity $ 200,000,000          
2025 Credit Facility            
Line Of Credit Facility [Line Items]            
Line of credit facility, maximum borrowing capacity $ 500,000,000          
Credit facility maturity date Feb. 26, 2030          
Maximum net leverage ratio 400.00%          
Maximum net leverage ratio year two 375.00%          
Minimum fixed charge coverage ratio 125.00%          
Percentage of proceeds of debt, subject to customary exceptions 100.00%          
Percentage of proceeds of certain dispositions, subject to customary reinvestment rights 100.00%          
Percentage of proceeds of insurance or condemnation, subject to customary reinvestment rights 100.00%          
Weighted average interest rate     6.10% 7.20%    
Deferred debt issuance cost           $ 2,200,000
Maximum pro-forma leverage ratio 300.00%          
Minimum pro-forma fixed charge coverage ratio 125.00%          
2025 Credit Facility | Interest Rate Swap            
Line Of Credit Facility [Line Items]            
Weighted average interest rate     5.50% 5.80%    
Prior Credit Facility            
Line Of Credit Facility [Line Items]            
Deferred debt issuance cost $ 900,000          
Loan and Aircraft Security Agreement            
Line Of Credit Facility [Line Items]            
Notional amount   $ 10,900,000        
Percentage of prepayment fee for year one   3.00%        
Percentage of prepayment fee for year two   2.00%        
Percentage of prepayment fee for year three   1.00%        
Loan and Aircraft Security Agreement | SOFR            
Line Of Credit Facility [Line Items]            
Interest rate   1.86%        
Term Loan Facility | 2025 Credit Facility            
Line Of Credit Facility [Line Items]            
Line of credit facility, maximum borrowing capacity $ 200,000,000          
Installment repayment amount     $ 2,500,000      
Debt instrument, quarterly installment rate 1.25%          
Term Loan Facility | Prior Credit Facility            
Line Of Credit Facility [Line Items]            
Installment repayment amount       $ 15,000,000    
Revolving Line of Credit | 2025 Credit Facility            
Line Of Credit Facility [Line Items]            
Line of credit facility, maximum borrowing capacity $ 300,000,000          
Revolving Line of Credit | Letter of Credit | 2025 Credit Facility            
Line Of Credit Facility [Line Items]            
Line of credit facility, maximum borrowing capacity $ 20,000,000          
v3.25.4
Debt - Summary of 2025 Credit Facility Term Loan and Revolving Line of Credit Interest Rate Subject to Leverage Ratio and SOFR (Details) - 2025 Credit Facility Term Loan
Feb. 26, 2025
Pricing Tier1  
Subsequent Event [Line Items]  
Commitment Fee 0.25%
Letter of Credit Fee 2.50%
Pricing Tier1 | Minimum  
Subsequent Event [Line Items]  
Net Leverage Ratio 375.00%
Pricing Tier1 | Benchmark Spread  
Subsequent Event [Line Items]  
Interest rate 2.50%
Pricing Tier1 | Base Rate Plus  
Subsequent Event [Line Items]  
Interest rate 1.50%
Pricing Tier2  
Subsequent Event [Line Items]  
Commitment Fee 0.23%
Letter of Credit Fee 2.25%
Pricing Tier2 | Maximum  
Subsequent Event [Line Items]  
Net Leverage Ratio 375.00%
Pricing Tier2 | Minimum  
Subsequent Event [Line Items]  
Net Leverage Ratio 325.00%
Pricing Tier2 | Benchmark Spread  
Subsequent Event [Line Items]  
Interest rate 2.25%
Pricing Tier2 | Base Rate Plus  
Subsequent Event [Line Items]  
Interest rate 1.25%
Pricing Tier3  
Subsequent Event [Line Items]  
Commitment Fee 0.20%
Letter of Credit Fee 2.00%
Pricing Tier3 | Maximum  
Subsequent Event [Line Items]  
Net Leverage Ratio 325.00%
Pricing Tier3 | Minimum  
Subsequent Event [Line Items]  
Net Leverage Ratio 250.00%
Pricing Tier3 | Benchmark Spread  
Subsequent Event [Line Items]  
Interest rate 2.00%
Pricing Tier3 | Base Rate Plus  
Subsequent Event [Line Items]  
Interest rate 1.00%
Pricing Tier4  
Subsequent Event [Line Items]  
Commitment Fee 0.15%
Letter of Credit Fee 1.75%
Pricing Tier4 | Maximum  
Subsequent Event [Line Items]  
Net Leverage Ratio 250.00%
Pricing Tier4 | Minimum  
Subsequent Event [Line Items]  
Net Leverage Ratio 175.00%
Pricing Tier4 | Benchmark Spread  
Subsequent Event [Line Items]  
Interest rate 1.75%
Pricing Tier4 | Base Rate Plus  
Subsequent Event [Line Items]  
Interest rate 0.75%
Pricing Tier5  
Subsequent Event [Line Items]  
Commitment Fee 0.15%
Letter of Credit Fee 1.50%
Pricing Tier5 | Maximum  
Subsequent Event [Line Items]  
Net Leverage Ratio 175.00%
Pricing Tier5 | Benchmark Spread  
Subsequent Event [Line Items]  
Interest rate 1.50%
Pricing Tier5 | Base Rate Plus  
Subsequent Event [Line Items]  
Interest rate 0.50%
v3.25.4
Debt - Schedule of Interest Rate Swap Agreements (Details) - Interest Rate Swap Agreements
$ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
Debt Instrument One  
Line of Credit Facility [Line Items]  
Effective date May 30, 2023
Expiration date Apr. 27, 2026
Notional amount $ 70,000,000
Fixed rate 3.88%
Floating rate Benchmark Spread
Debt Instrument Two  
Line of Credit Facility [Line Items]  
Effective date Jun. 05, 2024
Expiration date Jun. 27, 2027
Notional amount $ 80,000,000
Fixed rate 3.27%
Floating rate Benchmark Spread
Debt Instrument Three  
Line of Credit Facility [Line Items]  
Effective date Apr. 01, 2025
Expiration date Apr. 27, 2028
Notional amount $ 50,000,000
Fixed rate 3.625%
Floating rate Benchmark Spread
v3.25.4
Debt - Schedule of Aggregate Annual Maturities of Long-Term Debt (Details)
$ in Thousands
Dec. 31, 2025
USD ($)
Line of Credit Facility [Line Items]  
2027 $ 11,318
2028 10,577
2029 15,000
2030 242,163
Total 279,058
2025 Credit Facility Revolving Line of Credit  
Line of Credit Facility [Line Items]  
2030 84,663
Total 84,663
2025 Credit Facility Term Loan  
Line of Credit Facility [Line Items]  
2027 10,000
2028 10,000
2029 10,000
2030 157,500
Total 187,500
Aircraft Loan  
Line of Credit Facility [Line Items]  
2027 1,318
2028 577
2029 5,000
Total $ 6,895
v3.25.4
Fair Value of Financial Instruments - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis using Significant Unobservable Inputs (Level 3) (Details) - Fair Value, Recurring - Level 3 - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]        
Total Assets $ 0 $ 1,544 $ 3,461 $ 6,046
Total Liabilities 18,067 53,351 25,057 33,986
Interest Rate Swap        
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]        
Total Assets 0 [1] 1,544 [1] 3,461 6,046
Total Liabilities [1] 429 0    
Business Acquisitions Contingent Consideration, Current        
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]        
Total Liabilities 14,883 26,872 3,592 3,801
Business Acquisitions Contingent Consideration, Long-Term        
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]        
Total Liabilities 2,755 6,255 2,448 4,454
Conversion Option        
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]        
Total Liabilities $ 0 $ 20,224 $ 19,017 $ 25,731
[1] Included in other non-current liabilities and other assets in the consolidated statement of financial position as of December 31, 2025 and consolidated statement of financial position as of December 31, 2024, respectively.
v3.25.4
Fair Value of Financial Instruments - Summary of Financial Instruments Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - Level 3 - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Beginning balance $ 53,351 $ 25,057 $ 33,986
Total Assets, Beginning balance 1,544 3,461 6,046
Acquisitions   28,003 1,127
Asset value, Changes in fair value included in earnings $ (1,544) $ (1,917) $ (2,585)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease) Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease) Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease)
Changes in fair value included in earnings $ 18,895 $ 1,741 $ (6,910)
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease) Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease) Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease)
Payment of contingent consideration payable $ (17,937) $ (1,450) $ (3,146)
Measurement period adjustment 1,548    
Ending balance 18,067 53,351 25,057
Total Assets, Ending balance 0 1,544 3,461
Business Acquisitions Contingent Consideration, Current      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Beginning balance 26,872 3,592 3,801
Acquisitions   5,104 397
Changes in fair value included in earnings (180) 1,879 (174)
Payment of contingent consideration payable (17,937) (1,450) (3,146)
Reclass of long term to short term contingent liabilities 4,580 17,747 2,714
Measurement period adjustment 1,548    
Ending balance 14,883 26,872 3,592
Business Acquisitions Contingent Consideration, Long-Term      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Beginning balance 6,255 2,448 4,454
Acquisitions   22,899 730
Changes in fair value included in earnings 1,080 (1,345) (22)
Reclass of long term to short term contingent liabilities (4,580) (17,747) (2,714)
Ending balance 2,755 6,255 2,448
Conversion Option      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Beginning balance 20,224 19,017 25,731
Changes in fair value included in earnings (20,224) 1,207 (6,714)
Ending balance 0 20,224 19,017
Interest Rate Swap      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Beginning balance [1] 0    
Total Assets, Beginning balance 1,544 [1] 3,461 6,046
Asset value, Changes in fair value included in earnings (1,544) (1,917) (2,585)
Changes in fair value included in earnings 429    
Ending balance [1] 429 0  
Total Assets, Ending balance $ 0 [1] $ 1,544 [1] $ 3,461
[1] Included in other non-current liabilities and other assets in the consolidated statement of financial position as of December 31, 2025 and consolidated statement of financial position as of December 31, 2024, respectively.
v3.25.4
Commitments and Contingencies - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Jul. 01, 2024
Commitments And Contingencies [Line Items]    
Lessee operating lease, expiration year 2040  
2021 Credit Facility    
Commitments And Contingencies [Line Items]    
Other Commitments, Description The Company has commitments under the 2025 Credit Facility, its Aircraft Loan, its equipment line of credit and its lease obligations (Note 7 and 13). The Company has entered into a purchase contract to purchase a total of $4.9 million of equipment over the course of 7 years that commenced on July 1, 2024, subject to a minimum spending requirement per year, measured from the commencement date and each anniversary thereof. The minimum spend requirement is $0.2 million, $0.4 million, and $0.9 million for 2025, 2026, and 2027, respectively, with the remainder subject to mutual agreement after the first three years. Amounts purchased for the year ended December 31, 2025 were $0.7 million.  
Purchase of equipment total amount   $ 4.9
Purchase contract, to purchase equipment over the course of period 7 years  
Purchase contract, to purchase equipment over the course of period commenced date Jul. 01, 2024  
Minimum spend, 2025 $ 0.2  
Minimum spend, 2026 0.4  
Minimum spend, 2027 0.9  
2025 Credit Facility    
Commitments And Contingencies [Line Items]    
Purchase amount $ 0.7  
Office Equipment    
Commitments And Contingencies [Line Items]    
Lessee operating lease, expiration year 2045  
v3.25.4
Convertible and Redeemable Series A-2 Preferred Stock - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 12 Months Ended
Jul. 01, 2025
Apr. 01, 2025
Apr. 13, 2020
Jan. 31, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Temporary Equity [Line Items]                
Period between issuance and expiration of outstanding warrant     10 years          
Proceeds from the Series A-2 and Warrant     $ 175,000          
Redeemed in cash         $ 122,235 $ 60,000    
Number of times increase in debt incurrence test ratio         4.5      
Compound embedded derivative, change in net fair value         $ 18,251 $ (3,123) $ 4,129  
Convertible And Redeemable Series A-2 Preferred Stock                
Temporary Equity [Line Items]                
Number of shares issued     17,500   0 11,667    
Par value per share     $ 0.0001   $ 0.0001 $ 0.0001    
Debt issuance costs, net     $ 1,300          
Redeemed in cash $ 62,200 $ 60,000   $ 60,000        
Number of shares outstanding 0       0 11,667 17,500 17,500
Preferred stock, dividends paid         $ 4,200 $ 11,100 $ 16,400  
Percentage of discount on common stock market price         15.00%      
Percentage of dividend rate steps downs per year         9.00%      
Percentage of dividend rate increase per annum in the event of noncompliance         12.00%      
Percentage of dividend rate increase per annum upon noncompliance occurred and thereafter         14.00%      
Number of days dividend increase rate applicable noncompliance event occurred         90 days      
Minimum repayment amount         $ 25,000      
Temporary equity description         The Company could, at its option on any one or more dates, redeem all or a minimum portion (the lesser of (i) $25.0 million in aggregate stated value of the Convertible and Redeemable Series A-2 Preferred Stock and (ii) all of the Convertible and Redeemable Series A-2 Preferred Stock then outstanding) of the outstanding Convertible and Redeemable Series A-2 Preferred Stock in cash. In January 2024, the Company redeemed $60.0 million in aggregate stated value of the Convertible and Redeemable Series A-2 Preferred Stock in cash. The Company redeemed $60.0 million and $62.2 million in aggregate stated value of the outstanding Series A-2 Preferred Stock on April 1, 2025 and July 1, 2025, respectively. The Company funded each 2025 redemption with cash on hand and borrowings under the 2025 Credit Facility. Following the July 2025 redemption, no A-2 Preferred Shares remained outstanding. Both 2025 redemptions were reflected in the Company's Consolidated Statements of Convertible and Redeemable Series A-2 Preferred Stock and Stockholders’ Equity and resulted in a reduction of temporary equity. The impact of the redemptions is also reflected in the calculation of earnings per share for the year ended December 31, 2025.      
Aggregate stated value of stock redeemed         $ 25,000      
Compound embedded derivative, fair value net         0 20,200    
Convertible And Redeemable Series A-2 Preferred Stock | Other Income/ Expense                
Temporary Equity [Line Items]                
Compound embedded derivative, change in net fair value         (20,200) $ 1,200 $ 6,700  
Convertible And Redeemable Series A-2 Preferred Stock | 60-Day Period Prior to Seventh Anniversary                
Temporary Equity [Line Items]                
Temporary equity convertible into common stock         60,000      
Convertible And Redeemable Series A-2 Preferred Stock | Year 5                
Temporary Equity [Line Items]                
Temporary equity convertible into common stock         60,000      
Convertible And Redeemable Series A-2 Preferred Stock | Year 6                
Temporary Equity [Line Items]                
Temporary equity convertible into common stock         $ 120,000      
v3.25.4
Stockholders' Equity - Additional Information (Details) - USD ($)
 12 Months Ended
Apr. 22, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2021
May 07, 2025
Jan. 31, 2025
Jan. 31, 2024
Jan. 31, 2023
Class Of Stock [Line Items]                  
Common stock, shares authorized   190,000,000 190,000,000            
Common stock, par value   $ 0.000004 $ 0.000004            
Net proceeds from sale of common stock     $ 121,776,000            
Stock repurchase program authorized amount           $ 40,000,000      
Total unrecognized stock compensation expense related to unvested options and restricted stock granted under the Plans   $ 46,400,000              
Unrecognized expense expected to be recognized period   1 year 8 months 12 days              
Share based compensation expense   $ 42,716,000 $ 64,665,000 $ 47,267,000          
Shares reserved for future issuance   7,445,571 7,326,507 9,439,847          
Supplemental Incentive Plans                  
Class Of Stock [Line Items]                  
Shares, granted   0 0 370,349          
Montrose 2017 Stock Incentive Plan                  
Class Of Stock [Line Items]                  
Shares of vested over period         5 years        
Shares, granted         1,671,391        
Share based, description         These RSUs represent the right to receive one share of the Company’s common stock upon vesting. These incentives were designed to (i) retain selected employees of the Company for a minimum of 5 years, (ii) reward selected employees for the Company’s significant outperformance and stockholder value creation in 2021, and (iii) provide incentives to selected employees of the Company to accelerate value creation for stockholders and other stakeholders over the next five-year period.        
Shares reserved for future issuance   6,877,744 [1] 6,645,618 [1] 8,647,656 [1]     1,372,373 1,207,563 1,189,801
Stock options granted   0 0 253,980          
Montrose Amended and Restated 2013 Stock Option Plan                  
Class Of Stock [Line Items]                  
Shares outstanding from exercised options   1,850,316 1,716,200 1,549,788          
RSUs                  
Class Of Stock [Line Items]                  
Restricted shares outstanding   2,324,404 3,148,847 2,846,019          
RSUs | Supplemental Incentive Plans                  
Class Of Stock [Line Items]                  
Shares of vested over period       4 years          
Shares, vested       237,634          
RSUs | Supplemental Incentive Plans | On the date of grant                  
Class Of Stock [Line Items]                  
Shares, vesting rights, percentage       33.33%          
RSUs | Supplemental Incentive Plans | On the one-year anniversary of the grant                  
Class Of Stock [Line Items]                  
Shares, vesting rights, percentage       33.33%          
RSUs | Supplemental Incentive Plans | On the two-year anniversary of the grant                  
Class Of Stock [Line Items]                  
Shares, vesting rights, percentage       33.33%          
RSUs | Montrose 2017 Stock Incentive Plan                  
Class Of Stock [Line Items]                  
Shares, granted         1,355,182        
Shares, vesting rights, percentage         50.00%        
Shares reserved for future issuance         135,517        
RSUs | Montrose 2017 Stock Incentive Plan | On the date of grant                  
Class Of Stock [Line Items]                  
Shares, vesting rights, percentage         50.00%        
Performance-Vested RSUs | Montrose 2017 Stock Incentive Plan                  
Class Of Stock [Line Items]                  
Shares, granted         316,209        
Shares, vesting rights, percentage         50.00%        
Performance-Vested RSUs | Montrose 2017 Stock Incentive Plan | On the date of grant                  
Class Of Stock [Line Items]                  
Shares, vesting rights, percentage         50.00%        
Stock Appreciation Rights (SARs)                  
Class Of Stock [Line Items]                  
Share based compensation expense   $ 0 $ 27,205,000 $ 9,185,000          
Stock Appreciation Rights (SARs) | Two Thousand Seventeen Plan                  
Class Of Stock [Line Items]                  
Shares of vested over period         5 years        
Shares, granted         3,000,000        
Exercise price         $ 66.79        
Fair value vested in period   $ 46,000,000              
Amortization period   5 years              
Remaining unamortized value   $ 18,000,000              
Stock Options                  
Class Of Stock [Line Items]                  
Share based compensation expense   $ 1,604,000 3,794,000 6,570,000          
Stock Options | Montrose 2017 Stock Incentive Plan | Board of Directors                  
Class Of Stock [Line Items]                  
Shares of vested over period   4 years              
Stock Options | Montrose 2017 Stock Incentive Plan | Executive Officers                  
Class Of Stock [Line Items]                  
Shares of vested over period   3 years              
Vesting frequency of period   1 year              
Stock Options | Montrose 2017 Stock Incentive Plan | On the two-year anniversary of the grant | Board of Directors                  
Class Of Stock [Line Items]                  
Shares, vesting rights, percentage   50.00%              
Stock Options | Montrose 2017 Stock Incentive Plan | Fourth Anniversary | Board of Directors                  
Class Of Stock [Line Items]                  
Shares, vesting rights, percentage   50.00%              
Restricted Stock                  
Class Of Stock [Line Items]                  
Share based compensation expense   $ 41,112,000 $ 33,666,000 $ 31,512,000          
Restricted Stock | Montrose 2017 Stock Incentive Plan                  
Class Of Stock [Line Items]                  
Shares RSAs granted   46,899 23,961 17,346          
Common Stock                  
Class Of Stock [Line Items]                  
Issuance of common stock pursuant to follow-on offering, shares     3,450,000            
Follow-on Offering | Common Stock                  
Class Of Stock [Line Items]                  
Issuance of common stock pursuant to follow-on offering, shares 3,450,000                
Net proceeds from sale of common stock $ 121,800,000                
Underwriters | Common Stock                  
Class Of Stock [Line Items]                  
Initial Shares of public offering price $ 37.15                
Discounts and commisions per share $ 1.67175                
[1] In January 2025, January 2024 and January 2023 the Board of Directors ratified the addition of 1,372,373, 1,207,563 and 1,189,801 shares of common stock, respectively, to the number of shares available for issuance under the 2017 Plan pursuant to the annual increase provision of such plan. Unless the Board of Directors determines otherwise, additional annual increases will be effective on each January 1, through January 1, 2027. The 2017 Plan permits the company to settle awards, if and when vested, in cash at its discretion. Pursuant to the terms of the 2017 Plan, the number of shares authorized for issuance thereunder will only be reduced with respect to shares of common stock actually issued upon exercise or settlement of an award. Shares of common stock subject to awards that have been canceled, expired, forfeited or otherwise not issued under an award and shares of common stock subject to awards settled in cash do not count as shares of common stock issued under the 2017 Plan. Shares reserved for future issuance as of December 31, 2023 includes awards of SARs approved in December 2021 that were subject to vesting based on the achievement of certain market conditions, which had not yet been achieved when these awards were cancelled, effective as of December 31, 2024. See “Stock Appreciation Rights” above for additional information on stock appreciation rights.
v3.25.4
Stockholders' Equity - Summary of Number of Shares Authorized to be Issued and Available for Grant (Details) - shares
Dec. 31, 2025
Jan. 31, 2025
Dec. 31, 2024
Jan. 31, 2024
Dec. 31, 2023
Jan. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Shares authorized to be issued 10,946,868   9,574,495   8,366,932  
Shares available for grant [1] 2,359,812   1,683,352   662,662  
2017 Plan            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Shares authorized to be issued 8,914,149   7,538,276   6,330,713  
Shares available for grant 2,359,812 [1] 1,372,373 1,683,352 [1] 1,207,563 662,662 [1] 1,189,801
2013 Plan            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Shares authorized to be issued 2,032,719   2,036,219   2,036,219  
[1] In January 2025, January 2024 and January 2023 the Board of Directors ratified the addition of 1,372,373, 1,207,563 and 1,189,801 shares of common stock, respectively, to the number of shares available for issuance under the 2017 Plan pursuant to the annual increase provision of such plan. Unless the Board of Directors determines otherwise, additional annual increases will be effective on each January 1, through January 1, 2027. The 2017 Plan permits the company to settle awards, if and when vested, in cash at its discretion. Pursuant to the terms of the 2017 Plan, the number of shares authorized for issuance thereunder will only be reduced with respect to shares of common stock actually issued upon exercise or settlement of an award. Shares of common stock subject to awards that have been canceled, expired, forfeited or otherwise not issued under an award and shares of common stock subject to awards settled in cash do not

count as shares of common stock issued under the 2017 Plan. Shares available for grant as of December 31, 2023 excluded awards of stock appreciation rights approved in December 2021 that were subject to vesting based on the achievement of certain market conditions, which had not yet been achieved when these awards were cancelled, effective as of December 31, 2024. See “Stock Appreciation Rights” below for additional information on stock appreciation rights.
v3.25.4
Stockholders' Equity - Summary of Number of Shares Authorized to be Issued and Available for Grant (Parenthetical) (Details) - shares
Dec. 31, 2025
Jan. 31, 2025
Dec. 31, 2024
Jan. 31, 2024
Dec. 31, 2023
Jan. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Shares available for grant [1] 2,359,812   1,683,352   662,662  
2017 Plan            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Shares available for grant 2,359,812 [1] 1,372,373 1,683,352 [1] 1,207,563 662,662 [1] 1,189,801
[1] In January 2025, January 2024 and January 2023 the Board of Directors ratified the addition of 1,372,373, 1,207,563 and 1,189,801 shares of common stock, respectively, to the number of shares available for issuance under the 2017 Plan pursuant to the annual increase provision of such plan. Unless the Board of Directors determines otherwise, additional annual increases will be effective on each January 1, through January 1, 2027. The 2017 Plan permits the company to settle awards, if and when vested, in cash at its discretion. Pursuant to the terms of the 2017 Plan, the number of shares authorized for issuance thereunder will only be reduced with respect to shares of common stock actually issued upon exercise or settlement of an award. Shares of common stock subject to awards that have been canceled, expired, forfeited or otherwise not issued under an award and shares of common stock subject to awards settled in cash do not

count as shares of common stock issued under the 2017 Plan. Shares available for grant as of December 31, 2023 excluded awards of stock appreciation rights approved in December 2021 that were subject to vesting based on the achievement of certain market conditions, which had not yet been achieved when these awards were cancelled, effective as of December 31, 2024. See “Stock Appreciation Rights” below for additional information on stock appreciation rights.
v3.25.4
Stockholders' Equity - Schedule of Stock Compensation Expense (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense $ 42,716 $ 64,665 $ 47,267
Cost of Revenue      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense 5,358 4,801 3,346
Selling, General and Administrative Expenses      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense 37,358 59,864 43,921
Stock Options      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense 1,604 3,794 6,570
Stock Options | Cost of Revenue      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense 729 1,223 1,685
Stock Options | Selling, General and Administrative Expenses      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense 875 2,571 4,885
Restricted Stock      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense 41,112 33,666 31,512
Restricted Stock | Cost of Revenue      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense 4,629 3,578 1,661
Restricted Stock | Selling, General and Administrative Expenses      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense 36,483 30,088 29,851
Stock Appreciation Rights (SARs)      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense 0 27,205 9,185
Stock Appreciation Rights (SARs) | Selling, General and Administrative Expenses      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock compensation expense $ 0 $ 27,205 $ 9,185
v3.25.4
Stockholders' Equity - Schedule of Restricted Stock Activity (Details) - Montrose 2017 Stock Incentive Plan - $ / shares
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Shares, Granted       1,671,391
Weighted-Average Grant Date Fair Value        
Weighted Average Grant Date Fair Value per Share Granted     $ 13.98  
Restricted Stock Units Awards        
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Beginning outstanding shares 2,617,059 2,468,722 1,777,715  
Shares, Granted 1,399,351 359,749 793,133  
Shares, Forfeited/ cancelled (166,158) (56,921) (11,311)  
Shares, Vested [1] (1,525,848) (154,491) (90,815)  
Ending outstanding shares 2,324,404 2,617,059 2,468,722  
Weighted-Average Grant Date Fair Value        
Weighted Average Grant Date Fair Value per Share Granted $ 18.27 $ 39.75 $ 34.33  
Weighted Average Grant Date Fair Value per Share Forfeited/ cancelled 27.76 37.32 32.13  
Weighted-Average Grant Date Fair Value, Vested [1] $ 49.25 $ 36.82 $ 36.77  
[1]

(1) The 2025 vested shares amount includes 406,655 shares withheld related to net share settlement of equity awards.
v3.25.4
Stockholders' Equity - Schedule of Restricted Stock Activity (Parenthetical) (Details)
 12 Months Ended
Dec. 31, 2025
shares
Restricted Stock Units Awards | Montrose 2017 Stock Incentive Plan  
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]  
Shares withheld related to net share settlement of equity awards 406,655
v3.25.4
Stockholders' Equity - Summary of Stock Option Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Montrose 2017 Stock Incentive Plan        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]        
Options to Purchase Common Stock Outstanding Beginning Balance 2,345,207 2,516,272 2,579,566  
Options to Purchase Common Stock Granted 0 0 253,980  
Options to Purchase Common Stock Forfeited/cancelled (55,313) (78,130) (134,170)  
Options to Purchase Common Stock Expired (71,812) (37,825) (6,450)  
Options to Purchase Common Stock Exercised (24,554) (55,110) (176,654)  
Options to Purchase Common Stock Outstanding Ending Balance 2,193,528 2,345,207 2,516,272 2,579,566
Options to Purchase Common Stock Exercisable 1,992,545      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]        
Weighted-Average Exercise Price per Share Beginning Balance $ 30.62 $ 30.92 $ 31.00  
Weighted-Average Exercise Price per Share Granted     32.41  
Weighted-Average Exercise Price per Share Forfeited/cancelled 40.81 38.57 36.01  
Weighted-Average Exercise Price per Share Expired 37.12 41.90 32.03  
Weighted-Average Exercise Price per Share Exercised 14.88 25.48 24.12  
Weighted-Average Exercise Price per Share Ending Balance 30.33 30.62 30.92 $ 31.00
Weighted-Average Exercise Price per Share, Exercisable 29.41      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]        
Weighted Average Grant Date Fair Value per Share Beginning Balance 16.32 15.95 15.00  
Weighted Average Grant Date Fair Value per Share Granted     13.98  
Weighted Average Grant Date Fair Value per Share Ending Balance $ 16.32 $ 16.32 $ 15.95 $ 15.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]        
Weighted Average Remaining Contract Life (in Years) Outstanding 4 years 10 months 24 days 6 years 7 years 7 years 9 months 18 days
Weighted Average Remaining Contract Life, Exercisable 4 years 9 months 18 days      
Aggregate Intrinsic Value of In-The-Money Options Outstanding $ 776 $ 13,825 $ 37,295  
Aggregate Intrinsic Value of In-The-Money Options Exercised 266 776 3,726  
Aggregate Intrinsic Value of In-The-Money Options Outstanding 6,109 $ 776 $ 13,825 $ 37,295
Aggregate Intrinsic Value of In-The-Money Options Exercisable $ 6,109      
Montrose Amended and Restated 2013 Stock Option Plan        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]        
Options to Purchase Common Stock Outstanding Beginning Balance 680,889 792,191 855,695  
Options to Purchase Common Stock Expired (3,500)   (800)  
Options to Purchase Common Stock Exercised (109,562) (111,302) (62,704)  
Options to Purchase Common Stock Outstanding Ending Balance 567,827 680,889 792,191 855,695
Options to Purchase Common Stock Exercisable 567,827      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]        
Weighted-Average Exercise Price per Share Beginning Balance $ 6.49 $ 6.40 $ 6  
Weighted-Average Exercise Price per Share Expired 6.03   6.03  
Weighted-Average Exercise Price per Share Exercised 6.4 5.87 6.82  
Weighted-Average Exercise Price per Share Ending Balance 6.51 6.49 6.40 $ 6
Weighted-Average Exercise Price per Share, Exercisable 6.51      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]        
Weighted Average Grant Date Fair Value per Share Beginning Balance 2.51 2.16 2.1  
Weighted Average Grant Date Fair Value per Share Ending Balance $ 2.51 $ 2.51 $ 2.16 $ 2.1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]        
Weighted Average Remaining Contract Life (in Years) Outstanding 6 months 1 year 6 months 2 years 4 months 24 days 3 years 3 months 18 days
Weighted Average Remaining Contract Life, Exercisable 6 months      
Aggregate Intrinsic Value of In-The-Money Options Outstanding $ 8,211 $ 20,380 $ 32,478  
Aggregate Intrinsic Value of In-The-Money Options Exercised 1,991 3,042 1,950  
Aggregate Intrinsic Value of In-The-Money Options Outstanding 10,401 $ 8,211 $ 20,380 $ 32,478
Aggregate Intrinsic Value of In-The-Money Options Exercisable $ 10,401      
v3.25.4
Stockholders' Equity - Summary of Weighted Average Assumptions Used in Black-Sholes Option-pricing Model (Details)
 12 Months Ended
Dec. 31, 2023
$ / shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Common stock value (per share) $ 32.41
Expected volatility 33.55%
Risk- free interest rate 3.77%
Expected life (years) 7 years
Forfeiture rate 0.00%
Dividend rate 0.00%
v3.25.4
Stockholders' Equity - Schedule of Common Stock Reserved for Future Issuance (Details) - shares
Dec. 31, 2025
Jan. 31, 2025
Dec. 31, 2024
Jan. 31, 2024
Dec. 31, 2023
Jan. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Common stock reserved for future issuance 7,445,571   7,326,507   9,439,847  
Montrose 2013 Stock Incentive Plan            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Common stock reserved for future issuance 567,827   680,889   792,191  
Montrose 2017 Stock Incentive Plan            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Common stock reserved for future issuance 6,877,744 [1] 1,372,373 6,645,618 [1] 1,207,563 8,647,656 [1] 1,189,801
[1] In January 2025, January 2024 and January 2023 the Board of Directors ratified the addition of 1,372,373, 1,207,563 and 1,189,801 shares of common stock, respectively, to the number of shares available for issuance under the 2017 Plan pursuant to the annual increase provision of such plan. Unless the Board of Directors determines otherwise, additional annual increases will be effective on each January 1, through January 1, 2027. The 2017 Plan permits the company to settle awards, if and when vested, in cash at its discretion. Pursuant to the terms of the 2017 Plan, the number of shares authorized for issuance thereunder will only be reduced with respect to shares of common stock actually issued upon exercise or settlement of an award. Shares of common stock subject to awards that have been canceled, expired, forfeited or otherwise not issued under an award and shares of common stock subject to awards settled in cash do not count as shares of common stock issued under the 2017 Plan. Shares reserved for future issuance as of December 31, 2023 includes awards of SARs approved in December 2021 that were subject to vesting based on the achievement of certain market conditions, which had not yet been achieved when these awards were cancelled, effective as of December 31, 2024. See “Stock Appreciation Rights” above for additional information on stock appreciation rights.
v3.25.4
Stockholders' Equity - Schedule of Common Stock Reserved for Future Issuance (Parenthetical) (Details) - shares
Dec. 31, 2025
Jan. 31, 2025
Dec. 31, 2024
Jan. 31, 2024
Dec. 31, 2023
Jan. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Common stock reserved for future issuance 7,445,571   7,326,507   9,439,847  
Montrose 2017 Stock Incentive Plan            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Common stock reserved for future issuance 6,877,744 [1] 1,372,373 6,645,618 [1] 1,207,563 8,647,656 [1] 1,189,801
[1] In January 2025, January 2024 and January 2023 the Board of Directors ratified the addition of 1,372,373, 1,207,563 and 1,189,801 shares of common stock, respectively, to the number of shares available for issuance under the 2017 Plan pursuant to the annual increase provision of such plan. Unless the Board of Directors determines otherwise, additional annual increases will be effective on each January 1, through January 1, 2027. The 2017 Plan permits the company to settle awards, if and when vested, in cash at its discretion. Pursuant to the terms of the 2017 Plan, the number of shares authorized for issuance thereunder will only be reduced with respect to shares of common stock actually issued upon exercise or settlement of an award. Shares of common stock subject to awards that have been canceled, expired, forfeited or otherwise not issued under an award and shares of common stock subject to awards settled in cash do not count as shares of common stock issued under the 2017 Plan. Shares reserved for future issuance as of December 31, 2023 includes awards of SARs approved in December 2021 that were subject to vesting based on the achievement of certain market conditions, which had not yet been achieved when these awards were cancelled, effective as of December 31, 2024. See “Stock Appreciation Rights” above for additional information on stock appreciation rights.
v3.25.4
Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Earnings Per Share [Abstract]      
Net (loss) $ (843) $ (62,314) $ (30,859)
Convertible and Redeemable Series A-2 Preferred Stock dividend (4,150) (11,064) (16,400)
Net loss attributable to common stockholders -basic (4,993) (73,378) (47,259)
Net loss attributable to common stockholders -diluted $ (4,993) $ (73,378) $ (47,259)
Weighted-average number of shares of common stock outstanding - basic 35,120 33,061 30,058
Weighted-average number of shares of common stock outstanding - diluted 35,120 33,061 30,058
Net loss per share attributable to common stockholders - basic $ (0.14) $ (2.22) $ (1.57)
Net loss per share attributable to common stockholders - diluted $ (0.14) $ (2.22) $ (1.57)
v3.25.4
Net Loss Per Share - Common Stock Equivalents Excluded from Calculation of Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Details) - shares
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Stock Options      
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of loss per share amount [1] 2,959,850 3,026,096 3,308,463
Restricted Stock      
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of loss per share amount [1] 2,324,404 2,617,059 2,468,722
Series A-2 Preferred Stock      
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of loss per share amount [1] 2,654,739 4,293,793 5,952,609
Stock Appreciation Rights (SARs)      
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of loss per share amount [1],[2] 0 0 3,000,000
[1] Includes 2,116,319, 2,374,716 and 7,660,169 shares underlying equity awards that were out of the money as of December 31, 2025, 2024 and 2023, respectively.
[2] Effective December 31, 2024, the Board of Directors approved the SAR Cancellation (Note 17).
v3.25.4
Net Loss Per Share - Common Stock Equivalents Excluded from Calculation of Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Parenthetical) (Details) - shares
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Earnings Per Share [Abstract]      
Number of shares out of money 2,116,319 2,374,716 7,660,169
v3.25.4
Segment Information and Geographic Location Information - Additional Information (Details)
 12 Months Ended
Dec. 31, 2025
OperatingUnit
Segment
Segment Reporting [Abstract]  
Number of operating units | OperatingUnit 6
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration] srt:ChiefExecutiveOfficerMember
Number of reportable segments | Segment 3
v3.25.4
Segment Information and Geographic Location Information - Components of Segment Revenues, Segment Expenses and Segment Adjusted EBITDA (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Segment Reporting Information [Line Items]      
Segment Revenues $ 830,538 $ 696,395 $ 624,208
Segment Adjusted EBITDA 169,084 136,880 116,452
Assessment, Permitting and Response | Operating Segments      
Segment Reporting Information [Line Items]      
Segment Revenues 307,428 214,850 220,727
Segment Expenses 238,973 166,830 168,579
Segment Adjusted EBITDA 68,455 48,020 52,148
Measurement and Analysis | Operating Segments      
Segment Reporting Information [Line Items]      
Segment Revenues [1] 245,860 224,366 197,095
Segment Expenses [1] 181,509 173,845 159,878
Segment Adjusted EBITDA [1] 64,351 50,521 37,217
Remediation and Reuse | Operating Segments      
Segment Reporting Information [Line Items]      
Segment Revenues 277,250 257,179 206,386
Segment Expenses 240,972 218,840 179,299
Segment Adjusted EBITDA $ 36,278 $ 38,339 $ 27,087
[1] Includes revenue of $8.8 million and Adjusted EBITDA of $2.1 million from the Discontinued Specialty Lab for the year ended December 31, 2023. The lab was discontinued in the year ended December 31, 2023.
v3.25.4
Segment Information and Geographic Location Information - Components of Segment Revenues, Segment Expenses and Segment Adjusted EBITDA (Parenthetical) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Segment Reporting Information [Line Items]      
Segment Revenues $ 830,538 $ 696,395 $ 624,208
Total Reportable Segments $ 169,084 $ 136,880 116,452
Discontinuing Specialty Lab      
Segment Reporting Information [Line Items]      
Segment Revenues     8,800
Total Reportable Segments     $ 2,100
v3.25.4
Segment Information and Geographic Location Information - Reconciliation of Segment Measure to Income (Loss) Before Expense from Income Taxes (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Segment Reporting [Abstract]      
Total Reportable Segments $ 169,084 $ 136,880 $ 116,452
Corporate and Other (52,920) (41,092) (37,876)
Interest expense, net (19,567) (15,862) (7,793)
Depreciation and amortization (50,915) (52,762) (45,780)
Stock-based compensation (42,716) (64,665) (47,267)
Acquisition costs [1] (1,825) (7,827) (6,930)
Fair value changes in financial instruments 18,251 (3,124) 4,129
Fair value changes in business acquisition contingencies (900) (534) (84)
Expenses related to financing transactions (163) (317) (35)
Discontinued Specialty Lab [2]   (692) (6,112)
Business line restructuring costs [3] (2,633) (146) (9)
Other losses or expenses [4] (4,475) (4,177) (534)
Income (loss) before expense from income taxes $ 11,221 $ (54,318) $ (31,839)
[1] Includes financial and tax diligence, consulting, legal, valuation, accounting, travel and acquisition-related incentives related to our acquisition and integration activity.
[2] Amounts consist of operating losses before depreciation related to the Discontinued Specialty Lab.
[3] Amounts consist of severance costs related to organizational restructuring of business lines within the Company's Assessment, Permitting and Response and Remediation and Reuse segments, including costs incurred to wind down its renewable energy business.
[4] The year ended December 31, 2025 consists primarily of losses and costs associated with exiting operations in Europe, nonrecurring rebranding expenses, and third party expenses associated with the independent review and analysis of assertions in a short seller report regarding the Company. The year ended December 31, 2024 consists primarily of non-recurring costs to centralize certain back-office functions, lease abandonment costs, and third party expenses associated with the independent review and analysis of assertions in a short seller report regarding the Company. The year ended December 31, 2023 consists primarily of expenses related to an aircraft accident, net of insurance gain, as well as a gain on the surrender of a lease.
v3.25.4
Segment Information and Geographic Location Information - Schedule of Revenues by Geographic Location (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]      
Total Revenue $ 830,538 $ 696,395 $ 624,208
United States      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Total Revenue 678,382 550,323 539,578
Canada      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Total Revenue 120,762 115,918 72,608
Other International      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Total Revenue $ 31,394 $ 30,154 $ 12,022
v3.25.4
Segment Information and Geographic Location Information - Schedule of Long-lived Assets by Geographic Location (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Revenues from External Customers and Long-Lived Assets [Line Items]    
Total property and equipment - net $ 63,853 $ 63,776
United States    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Total property and equipment - net 58,590 57,730
Canada    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Total property and equipment - net 4,311 5,070
Other International    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Total property and equipment - net $ 952 $ 976
v3.25.4
Related-Party Transactions - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Related Party Transactions [Abstract]      
Related party transaction amount $ 0 $ 0 $ 0
v3.25.4
Defined Contribution Plan - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Defined Contribution Plan Disclosure [Line Items]      
Defined contribution plan, description 401(k) Savings Plan    
Defined contribution plan, maximum annual contributions per employee, percent 85.00% 85.00% 85.00%
Defined contribution plan, employer matching contribution, percent of match 100.00%    
Defined contribution plan participant's elective deferrals maximum percentage of participant's compensation 3.00%    
Defined contribution plan percentage of participant's elective deferrals 50.00%    
Selling, General and Administrative Expenses      
Defined Contribution Plan Disclosure [Line Items]      
Defined contribution plan, employer discretionary contribution amount $ 10.4 $ 9.1 $ 7.9
Minimum      
Defined Contribution Plan Disclosure [Line Items]      
Defined contribution plan participant's compensation percent 3.00%    
Maximum      
Defined Contribution Plan Disclosure [Line Items]      
Defined contribution plan participant's compensation percent 5.00%    
v3.25.4
Subsequent Events - Additional Information (Details) - Subsequent Event - Foreign Currency Forward Contracts
$ in Millions
Feb. 16, 2026
USD ($)
Subsequent Event [Line Items]  
Derivative, notional amount $ 22.4
Derivative, description of terms On February 16, 2026, the Company entered into foreign currency forward contracts having a total notional amount of approximately $22.4 million. The purpose of these contracts was to hedge a portion of the Company's 2026 forecasted foreign exchange exposure to fluctuations in the AUD and CAD exchange rates relative to the U.S. dollar. The contracts mature monthly and expire in December 2026.