TETRA TECH INC, 10-Q filed on 1/31/2025
Quarterly Report
v3.24.4
Cover - shares
 3 Months Ended
Dec. 29, 2024
Jan. 20, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Dec. 29, 2024  
Document Transition Report false  
Entity File Number 0-19655  
Entity Registrant Name TETRA TECH, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 95-4148514  
Entity Address, Address Line One 3475 East Foothill Boulevard  
Entity Address, City or Town Pasadena  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 91107  
City Area Code 626  
Local Phone Number 351-4664  
Title of 12(b) Security Common Stock, $0.01 par value  
Trading Symbol TTEK  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   268,036,087
Entity Central Index Key 0000831641  
Amendment Flag false  
Current Fiscal Year End Date --09-28  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q1  
v3.24.4
Consolidated Balance Sheets - USD ($)
$ in Thousands
Dec. 29, 2024
Sep. 29, 2024
Current assets:    
Cash and cash equivalents $ 248,104 $ 232,689
Accounts receivable, net 1,117,666 1,051,461
Contract assets 122,310 129,678
Prepaid expenses and other current assets 143,768 113,555
Total current assets 1,631,848 1,527,383
Property and equipment, net 67,102 73,065
Right-of-use assets, operating leases 172,080 177,950
Goodwill 1,968,684 2,046,569
Intangible assets, net 142,097 160,585
Deferred tax assets 96,916 105,529
Other non-current assets 100,457 101,595
Total assets 4,179,184 4,192,676
Current liabilities:    
Accounts payable 238,157 197,440
Accrued compensation 222,549 332,096
Contract liabilities 359,957 351,738
Short-term lease liabilities, operating leases 61,184 63,419
Current contingent earn-out liabilities 24,153 26,934
Other current liabilities 361,345 247,900
Total current liabilities 1,267,345 1,219,527
Deferred tax liabilities 24,902 30,162
Long-term debt 888,450 812,634
Long-term lease liabilities, operating leases 134,759 140,095
Non-current contingent earn-out liabilities 22,007 21,812
Other non-current liabilities 149,702 138,033
Commitments and contingencies (Note 17)
Equity:    
Preferred stock - authorized, 2,000 shares of $0.01 par value; no shares issued and outstanding at December 29, 2024 and September 29, 2024 0 0
Common stock - authorized, 750,000 shares of $0.01 par value; issued and outstanding, 268,028 and 267,717 shares at December 29, 2024 and September 29, 2024, respectively 2,680 2,677
Additional paid-in capital 21,153 35,900
Accumulated other comprehensive loss (187,754) (78,875)
Retained earnings 1,855,818 1,870,620
Tetra Tech stockholders’ equity 1,691,897 1,830,322
Noncontrolling interests 122 91
Total stockholders' equity 1,692,019 1,830,413
Total liabilities and stockholders' equity $ 4,179,184 $ 4,192,676
v3.24.4
Consolidated Balance Sheets (Parenthetical) - $ / shares
Dec. 29, 2024
Sep. 29, 2024
Statement of Financial Position [Abstract]    
Preferred stock, authorized shares (in shares) 2,000,000 2,000,000
Preferred stock, par value (in dollars per share) $ 0.01 $ 0.01
Preferred stock, shares issued (in shares) 0 0
Preferred stock, shares outstanding (in shares) 0 0
Common stock, authorized shares (in shares) 750,000,000 750,000,000
Common stock, par value (in dollars per share) $ 0.01 $ 0.01
Common stock, shares issued (in shares) 268,028,000 267,717,000
Common stock, shares outstanding (in shares) 268,028,000 267,717,000
v3.24.4
Consolidated Statements of Income - USD ($)
shares in Thousands, $ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Revenue $ 1,420,561 $ 1,228,267
Gross profit 221,477 190,498
Selling, general and administrative expenses (83,951) (79,417)
Legal contingency costs (115,000) 0
Income from operations 22,526 111,081
Interest expense, net (7,218) (9,577)
Income before income tax expense 15,308 101,504
Income tax expense (14,530) (26,524)
Net income 778 74,980
Net income attributable to noncontrolling interests (31) (8)
Net income attributable to Tetra Tech, basic 747 74,972
Net income attributable to Tetra Tech, diluted $ 747 $ 74,972
Earnings per share attributable to Tetra Tech:    
Basic (in dollars per share) $ 0 $ 0.28
Diluted (in dollars per share) $ 0 $ 0.28
Weighted-average common shares outstanding:    
Basic (in shares) 267,854 266,585
Diluted (in shares) 271,886 268,690
Subcontractor costs    
Cost of revenue $ (223,231) $ (213,098)
Other costs of revenue    
Cost of revenue $ (975,853) $ (824,671)
v3.24.4
Consolidated Statements of Comprehensive Income (Loss) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Statement of Comprehensive Income [Abstract]    
Net income $ 778 $ 74,980
Other comprehensive (loss) income, net of tax    
Foreign currency translation adjustment, net of tax (108,846) 63,106
Net pension adjustments (33) (13)
Other comprehensive (loss) income, net of tax (108,879) 63,093
Comprehensive (loss) income, net of tax (108,101) 138,073
Less: Comprehensive income attributable to noncontrolling interests, net of tax 31 8
Comprehensive (loss) income attributable to Tetra Tech, net of tax $ (108,132) $ 138,065
v3.24.4
Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Cash flows from operating activities:    
Net income $ 778 $ 74,980
Adjustments to reconcile net income to net cash provided by operating activities:    
Depreciation and amortization 16,063 19,484
Amortization of stock-based awards 8,142 7,641
Deferred income taxes 767 (1,624)
Other non-cash items 775 123
Changes in operating assets and liabilities, net of effects of business acquisitions:    
Accounts receivable and contract assets (91,725) (22,288)
Prepaid expenses and other assets (26,186) (28,615)
Accounts payable 44,194 33,790
Accrued compensation (101,641) (80,069)
Contract liabilities 27,527 41,862
Income taxes receivable/payable (1,538) (15,941)
Cash settled on contingent earn-out liabilities (2,720) 0
Other liabilities 138,627 (20,097)
Net cash provided by operating activities 13,063 9,246
Cash flows from investing activities:    
Capital expenditures (3,433) (3,434)
Net cash used in investing activities (3,433) (3,434)
Cash flows from financing activities:    
Proceeds from borrowings 90,000 125,000
Repayments on long-term debt (15,000) (60,000)
Repurchases of common stock (25,000) 0
Shares repurchased for tax withholdings on share-based awards (13,307) (12,670)
Payments of contingent earn-out liabilities (145) (18,862)
Stock options exercised 114 335
Dividends paid (15,549) (13,873)
Principal payments on finance leases (1,719) (1,539)
Net cash provided by financing activities 19,394 18,391
Effect of exchange rate changes on cash and cash equivalents (13,609) 5,655
Net increase in cash and cash equivalents 15,415 29,858
Cash and cash equivalents at beginning of period 232,689 168,831
Cash and cash equivalents at end of period 248,104 198,689
Cash paid during the period for:    
Interest 4,295 6,369
Income taxes, net of refunds received of $1.7 million and $0.9 million $ 14,489 $ 43,297
v3.24.4
Consolidated Statements of Cash Flows (Parenthetical) - USD ($)
$ in Millions
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Statement of Cash Flows [Abstract]    
Income tax refunds $ 1.7 $ 0.9
v3.24.4
Consolidated Statements of Stockholders' Equity - USD ($)
shares in Thousands, $ in Thousands
Total
Total Tetra Tech Equity
Common Stock
Additional Paid-in Capital
Accumulated Other Comprehensive Loss
Retained Earnings
Non-Controlling Interests
Beginning balance (in shares) at Oct. 01, 2023     266,238        
Beginning balance at Oct. 01, 2023 $ 1,403,506 $ 1,403,433 $ 2,662 $ 0 $ (195,295) $ 1,596,066 $ 73
Increase (Decrease) in Stockholders' Equity [Roll Forward]              
Net income 74,980 74,972       74,972 8
Other comprehensive income (loss) 63,093 63,093     63,093    
Cash dividends per common share (13,873) (13,873)       (13,873)  
Stock-based compensation 7,641 7,641   7,641      
Restricted & performance shares released (in shares)     524        
Restricted & performance shares released (12,670) (12,670) $ 5 (12,675)      
Stock options exercised (in shares)     45        
Stock options exercised 335 335   335      
Shares issued for Employee Stock Purchase Plan (in shares)     522        
Shares issued for Employee Stock Purchase Plan 14,675 14,675 $ 5 14,670      
Ending balance (in shares) at Dec. 31, 2023     267,329        
Ending balance at Dec. 31, 2023 1,537,687 1,537,606 $ 2,672 9,971 (132,202) 1,657,165 81
Beginning balance (in shares) at Sep. 29, 2024     267,717        
Beginning balance at Sep. 29, 2024 1,830,413 1,830,322 $ 2,677 35,900 (78,875) 1,870,620 91
Increase (Decrease) in Stockholders' Equity [Roll Forward]              
Net income 778 747       747 31
Other comprehensive income (loss) (108,879) (108,879)     (108,879)    
Cash dividends per common share (15,549) (15,549)       (15,549)  
Stock-based compensation 8,142 8,142   8,142      
Restricted & performance shares released (in shares)     432        
Restricted & performance shares released (13,307) (13,307) $ 5 (13,312)      
Stock options exercised (in shares)     21        
Stock options exercised 114 114   114      
Shares issued for Employee Stock Purchase Plan (in shares)     458        
Shares issued for Employee Stock Purchase Plan 15,307 15,307 $ 4 15,303      
Stock repurchase (in shares)     (600)        
Stock repurchase (25,000) (25,000) $ (6) (24,994)      
Ending balance (in shares) at Dec. 29, 2024     268,028        
Ending balance at Dec. 29, 2024 $ 1,692,019 $ 1,691,897 $ 2,680 $ 21,153 $ (187,754) $ 1,855,818 $ 122
v3.24.4
Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Statement of Stockholders' Equity [Abstract]    
Dividend paid per share (in dollars per share) $ 0.058 $ 0.052
v3.24.4
Basis of Presentation
 3 Months Ended
Dec. 29, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Basis of Presentation Basis of Presentation
The accompanying unaudited consolidated financial statements and related notes of Tetra Tech, Inc. (“we,” “us,” “our” or "Tetra Tech") have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. They do not include all of the information and footnotes required by U.S. GAAP for complete financial statements and, therefore, should be read in conjunction with the audited consolidated financial statements and the notes contained in our Annual Report on Form 10-K for the fiscal year ended September 29, 2024.
These financial statements reflect all normal recurring adjustments that are considered necessary for a fair statement of our financial position, results of operations and cash flows for the interim periods presented. The results of operations and cash flows for any interim period are not necessarily indicative of results for the full fiscal year or for future fiscal years. Certain prior year amounts have been reclassified to conform to the current year presentation in the accompanying notes.
On July 29, 2024, our Board of Directors approved a five-for-one stock split of our common stock. The stock split had a record date of September 5, 2024 and an effective date of September 6, 2024. The par value per share of our common stock remains unchanged at $0.01 per share after the stock split. All prior-period share or per share amounts presented herein have been retroactively adjusted to reflect the stock split.
v3.24.4
Recent Accounting Pronouncements
 3 Months Ended
Dec. 29, 2024
Accounting Changes and Error Corrections [Abstract]  
Recent Accounting Pronouncements Recent Accounting Pronouncements
In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update (“ASU”) No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which requires that an entity report segment information in accordance with Topic 280, Segment Reporting. The amendments in the ASU are intended to improve reportable segment disclosure requirements primarily through enhanced disclosures about significant segment expenses. The amendments in this ASU are effective for fiscal years beginning after December 15, 2023 (fiscal 2025 year-end for us), and interim periods within fiscal years beginning after December 15, 2024 (first quarter of fiscal 2026 for us). Early adoption is permitted. The adoption of this ASU will not have a material impact on our consolidated financial statements.
In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which requires that an entity, on an annual basis, disclose additional income tax information, primarily related to the rate reconciliation and income taxes paid. The amendments in the ASU are intended to enhance the transparency and decision usefulness of income tax disclosures. The amendments in this ASU are effective for annual periods beginning after December 15, 2024 (fiscal 2026 for us). Early adoption is permitted. The adoption of this ASU will not have a material impact on our consolidated financial statements.
In November 2024, the FASB issued ASU No. 2024-03, Income Statement (Topic 220): Reporting Comprehensive Income. ASU 2024-03 does not change or remove current expense presentation requirements within the consolidated statements of income. However, the amendments require disclosure, on an annual and interim basis, of disaggregated information about certain income statement expense line items within the notes to the consolidated financial statements. The amendments in this update are effective for annual reporting periods beginning after December 15, 2026 (fiscal 2028 for us), and interim reporting periods beginning after December 15, 2027 (first quarter of fiscal 2029 for us). Early adoption is permitted. The adoption of this ASU will not have a material impact on our consolidated financial statements.
In November 2024, the FASB issued ASU No. 2024-04, Debt—Debt with Conversion and Other Options (Subtopic 470-20): Induced Conversions of Convertible Debt Instruments, which clarifies the requirements related to accounting for the settlement of a debt instrument as an induced conversion. The amendments in this update are effective for annual reporting periods beginning after December 15, 2025, including interim periods within those fiscal years (first quarter of fiscal 2027 for us). Early adoption is permitted. We are currently evaluating the impact of this guidance on our consolidated financial statements; however, we do not plan to adopt this ASU before fiscal 2027.
v3.24.4
Revenue and Contract Balances
 3 Months Ended
Dec. 29, 2024
Revenue from Contract with Customer [Abstract]  
Revenue and Contract Balances Revenue and Contract Balances
We disaggregate revenue by client sector and contract type, as we believe it best depicts how the nature, timing and uncertainty of our revenue and cash flows are affected by economic factors. The following tables present our revenue disaggregated by client sector and contract type (in thousands):
 Three Months Ended
 December 29,
2024		December 31,
2023
Client Sector:  
U.S. federal government (1)
$501,848 $382,076 
U.S. state and local government202,987 150,925 
U.S. commercial233,591 222,430 
International (2)
482,135 472,836 
Total$1,420,561 $1,228,267 
Contract Type:
Fixed-price$519,822 $471,442 
Time-and-materials598,948 549,651 
Cost-plus301,791 207,174 
Total$1,420,561 $1,228,267 
(1)    Includes revenue generated under U.S. federal government contracts performed outside the United States.
(2)    Includes revenue generated from non-U.S. clients, primarily in United Kingdom, Australia and Canada
Other than the U.S. federal government, no single client accounted for more than 10% of our revenue for the first quarters of fiscal 2025 and 2024.
Contract Assets and Contract Liabilities
We invoice customers based on the contractual terms of each contract. However, the timing of revenue recognition may differ from the timing of invoice issuance. Contract assets represent revenue recognized in excess of the amounts for which we have the contractual right to bill our customers. Such amounts are recoverable from customers based upon various measures of performance, including achievement of certain milestones or completion of a contract. In addition, many of our time-and-materials arrangements are billed in arrears pursuant to contract terms that are standard within the industry, resulting in contract assets and/or unbilled receivables being recorded, as revenue is recognized in advance of billings. Contract retentions, included in contract assets, represent amounts withheld by clients until certain conditions are met or the project is completed, which may extend beyond one year.
Contract liabilities consist of billings in excess of revenue recognized. Contract liabilities decrease as we recognize revenue from the satisfaction of the related performance obligation and increase as billings in advance of revenue recognition occur. Contract assets and liabilities are reported in a net position on a contract-by-contract basis at the end of each reporting period. There were no substantial non-current contract assets for the periods presented. Net contract assets/liabilities consisted of the following (in thousands):
As of
December 29,
2024		September 29, 2024
Contract assets (1)
$122,310 $129,678 
Contract liabilities - current
(359,957)(351,738)
Contract liabilities - non-current (2)
(8,035)— 
Net contract liabilities$(245,682)$(222,060)
(1)    Includes $8.4 million and $7.9 million of contract retentions at December 29, 2024 and September 29, 2024, respectively.
(2)    Reported under "Other non-current liabilities" on our consolidated balance sheet as of December 29,2024.
Our contract assets decreased, and contract liabilities increased in the first quarter of fiscal 2025 compared to fiscal 2024 year-end, due to the timing of our milestone billings on fixed-price contracts which were different from the timing of revenue recognition on those contracts. For the first three months of fiscal 2025 and 2024, we recognized revenue of approximately $116 million and $130 million, respectively, from the amounts included in the contract liability balances at the end of fiscal 2024 and 2023, respectively.
Revenue is recognized by measuring progress over time under Accounting Standards Codification Topic 606, "Revenue from Contracts with Customers". We estimate and measure progress on our contracts over time whereby we compare
our total costs incurred on each contract as a percentage of the total expected contract costs. Changes in those estimates could result in the recognition of cumulative catch-up adjustments to the contract’s inception-to-date revenue, costs and profit in the period in which such changes are made. As a result, in the first quarters of fiscal 2025 and 2024, we recognized net favorable revenue and operating income adjustments of $2.7 million and $5.7 million, respectively.
Changes in revenue and cost estimates could also result in a projected loss, determined at the contract level, which would be recorded immediately in earnings. At December 29, 2024 and September 29, 2024, our consolidated balance sheets included liabilities for anticipated losses of $13.2 million and $15.1 million, respectively. The estimated cost to complete these related contracts was approximately $96 million and $101 million at December 29, 2024 and September 29, 2024, respectively.
Accounts Receivable, Net
Net accounts receivable consisted of the following (in thousands):
As of
 December 29,
2024		September 29,
2024
Billed$707,357 $707,406 
Unbilled414,778 348,907 
Total accounts receivable1,122,135 1,056,313 
Allowance for doubtful accounts(4,469)(4,852)
Total accounts receivable, net$1,117,666 $1,051,461 
Billed accounts receivable represent amounts billed to clients that have not been collected. Unbilled accounts receivable, which represent an unconditional right to payment subject only to the passage of time, include unbilled amounts typically resulting from revenue recognized but not yet billed pursuant to contract terms or billed after the period end date. Substantially all of our unbilled receivables at December 29, 2024 are expected to be billed and collected within 12 months. The allowance for doubtful accounts represents amounts that are expected to become uncollectible or unrealizable in the future. We determine an estimated allowance for uncollectible accounts based on management's consideration of trends in the actual and forecasted credit quality of our clients, including delinquency and payment history; type of client, such as a government agency or a commercial sector client; and general economic and industry conditions, which may affect our clients' ability to pay.
Other than the U.S. federal government, no single client accounted for more than 10% of our accounts receivable at December 29, 2024 and September 29, 2024.
Remaining Unsatisfied Performance Obligation (“RUPO”)
Our RUPO represents a measure of the total dollar value of work to be performed on contracts awarded and in progress. We had $5.4 billion of RUPO at December 29, 2024. Our RUPO increases with awards from new contracts or additions on existing contracts, and decreases as work is performed and revenue is recognized on existing contracts. Our RUPO may also decrease when projects are canceled or modified in scope. We include a contract within our RUPO when the contract is awarded and an agreement on contract terms has been reached.
We expect to satisfy our RUPO at December 29, 2024 over the following periods (in thousands):
Amount
Within 12 months$3,673,959 
Beyond 1,717,412 
Total $5,391,371 
Although RUPO reflects business that is considered to be firm, cancellations, deferrals or scope adjustments may occur. Our RUPO is adjusted to reflect any known project cancellations, revisions to project scope and cost, foreign currency exchange fluctuations and project deferrals, as appropriate. Our operations and maintenance contracts can generally be terminated by the clients without a substantive financial penalty; therefore, the remaining performance obligations on such contracts are limited to the notice period required for the termination (usually 30, 60, or 90 days).
v3.24.4
Acquisitions
 3 Months Ended
Dec. 29, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]  
Acquisitions Acquisitions
In the second quarter of fiscal 2024, we acquired LS Technologies ("LST"), an innovative U.S. federal enterprise technology services and management consulting firm based in Fairfax, Virginia. LST provides high-end consulting and engineering services including advanced data analytics, cybersecurity and digital transformation solutions to U.S. government
clients. In the third quarter of fiscal 2024, we also acquired Convergence Controls & Engineering ("CCE"), an industry leader in process automation and systems integration solutions. CCE’s expertise includes customized digital controls and software solutions, advanced data analytics, cloud data integration, and cybersecurity applications. Both LST and CCE are included in our Government Services Group ("GSG") segment. The aggregate fair value of the purchase price of these two acquisitions was $120 million. This amount consisted of $93 million in initial cash payments, $4 million of cash holdback related to a tax reserve, and $23 million for the estimated fair value of contingent earn-out obligations, with a maximum of $60 million, based upon the achievement of specified operating income targets in each of the three years following the acquisition dates. The $120 million purchase price was allocated $12 million to net tangible assets, $23 million to identifiable intangible assets, and $85 million to goodwill. The purchase price allocation is preliminary and subject to adjustment as the estimates, assumptions, valuations and other analyses have not yet been finalized in order to make a definitive allocation. The results of LST and CCE have been included in our consolidated financial statements since the beginning of their respective closing dates. These acquisitions were not considered material, individually or in aggregate, to our consolidated financial statements. As a result, no pro forma information has been provided.
Our fiscal 2024 goodwill additions from the LST and CCE acquisitions reflect the extensive technical knowledge of the acquired workforces, the anticipated synergies in data analytics, cybersecurity and digital transformation services, and collective reputations of these acquisitions in providing mission critical solutions to both commercial and government customers. These goodwill additions are deductible for tax purposes.
Intangible assets with finite lives arise from business acquisitions and are amortized based on the period over which the contractual or economic benefit of the intangible assets are expected to be realized on a straight-line basis over the useful lives of the underlying assets, ranging from one to 12 years. These consist of client relations, backlog and trade names. For detailed information regarding our intangible assets, see Note 5, “Goodwill and Intangible Assets”.
Most of our acquisition agreements include contingent earn-out agreements, which are generally based on the achievement of future operating income thresholds. The contingent earn-out arrangements are based on our valuations of the acquired companies and reduce the risk of overpaying for acquisitions if the projected financial results are not achieved. The fair values of any earn-out arrangements are included as part of the purchase price of the acquired companies on their respective acquisition dates. For each transaction, we estimate the fair value of contingent earn-out payments as part of the initial purchase price and record the estimated fair value of contingent consideration as a liability in “Current contingent earn-out liabilities” and “Non-current contingent earn-out liabilities” on the consolidated balance sheets. We consider several factors when determining that contingent earn-out liabilities are part of the purchase price, including the following: (1) the valuation of our acquisitions is not supported solely by the initial consideration paid, and the contingent earn-out formula is a critical and material component of the valuation approach to determining the purchase price; and (2) the former owners of acquired companies that remain as key employees receive compensation other than contingent earn-out payments at a reasonable level compared with the compensation of our other key employees. The contingent earn-out payments are not affected by employment termination.
We measure our contingent earn-out liabilities at fair value on a recurring basis using significant unobservable inputs classified within Level 3 of the fair value hierarchy. We use a probability-weighted discounted income approach as a valuation technique to convert future estimated cash flows to a single present value amount. The significant unobservable inputs used in the fair value measurements are operating income projections over the earn-out period (generally three to five years) and the probability outcome percentages we assign to each scenario. Significant increases or decreases to either of these inputs in isolation would result in a significantly higher or lower liability, with a higher liability capped by the contractual maximum of the contingent earn-out obligation. Ultimately, the liability will be equivalent to the amount paid, and the difference between the fair value estimate and amount paid will be recorded in earnings. The amount paid that is less than or equal to the contingent earn-out liability on the acquisition date is reflected as cash used in financing activities in our consolidated statements of cash flows. Any amount paid in excess of the contingent earn-out liability on the acquisition date is reflected as cash used in operating activities in our consolidated statements of cash flows.
We review and reassess the estimated fair value of contingent consideration on a quarterly basis, and the updated fair value could differ materially from the initial estimates. Changes in the estimated fair value of our contingent earn-out liabilities related to the time component of the present value calculation are reported in interest expense. Adjustments to the estimated fair value related to changes in all other unobservable inputs are reported in operating income. In the first quarter of fiscal 2025, we evaluated our estimates for contingent consideration liabilities for the remaining earn-out periods for each individual acquisition, which included a review of their financial results to-date, the status of ongoing projects in their RUPO and the inventory of prospective new contract awards.
In the first quarters of fiscal 2025 and 2024, we recorded immaterial adjustments, individually and in aggregate, to our contingent earn-out liabilities and included the corresponding amount in our operating income.
The following table summarizes the changes in the fair value of estimated contingent consideration (in thousands):
Three Months Ended
 December 29,
2024		December 31,
2023
Beginning balance$48,746 $73,422 
Payments of contingent consideration(2,865)(18,862)
Adjustments to fair value recorded in earnings(366)(37)
Interest accretion expense645 471 
Effect of foreign currency exchange rate changes— 610 
Ending balance$46,160 $55,604 
Maximum potential payout at end of period$99,006 $92,253 
v3.24.4
Goodwill and Intangible Assets
 3 Months Ended
Dec. 29, 2024
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill and Intangible Assets Goodwill and Intangible Assets
The following table summarizes the changes in the carrying value of goodwill by reportable segment (in thousands):
 GSGCIGTotal
Balance at September 29, 2024$750,817 $1,295,752 $2,046,569 
Translation adjustments(4,124)(73,761)(77,885)
Balance at December 29, 2024$746,693 $1,221,991 $1,968,684 

Translation adjustments resulted from our goodwill amounts in foreign subsidiaries with functional currencies that are different than our reporting currency. The goodwill amounts presented in the table above are net of reductions from historical impairment adjustments. The gross amounts for GSG were $764.4 million and $768.5 million at December 29, 2024 and September 29, 2024, respectively, excluding accumulated impairment of $17.7 million at each date. The gross amounts of goodwill for Commercial/International Services Group ("CIG") were $1,343.5 million and $1,417.3 million at December 29, 2024 and September 29, 2024, respectively, excluding accumulated impairment of $121.5 million at each period end.
We perform our annual goodwill impairment review at the beginning of our fiscal fourth quarter. Our most recent annual review at July 1, 2024 (i.e. the first day of our fourth quarter in fiscal 2024) indicated that we had no impairment of goodwill, and all of our reporting units had estimated fair values that were in excess of their carrying values, including goodwill. At July 1, 2024, we had no reporting units that had estimated fair values that exceeded their carrying values by less than 72%.
We also regularly evaluate whether events and circumstances have occurred that may indicate a potential change in the recoverability of goodwill. We perform interim goodwill impairment reviews between our annual reviews if certain events and circumstances have occurred, such as a deterioration in general economic conditions; an increase in the competitive environment; a change in management, key personnel, strategy or customers; negative or declining cash flows; or a decline in actual or planned revenue or earnings compared with actual and projected results of relevant prior periods. Although we believe that our estimates of fair value for these reporting units are reasonable, if financial performance for these reporting units falls significantly below our expectations or market prices for similar business decline, the goodwill for these reporting units could become impaired.
The following table presents the gross amount and accumulated amortization of our acquired identifiable intangible assets with finite useful lives included in “Intangible assets, net” on the consolidated balance sheets ($ in thousands):

As of
 December 29, 2024September 29, 2024
 Weighted-
Average
Remaining Life
(in Years)		Gross
Amount		Accumulated
Amortization		Net AmountGross
Amount		Accumulated
Amortization		Net Amount
Client relations8.0$189,027 $(60,294)$128,733 $198,726 $(57,975)$140,751 
Backlog0.271,647 (70,405)1,242 75,194 (71,101)4,093 
Trade names1.238,349 (26,227)12,122 40,926 (25,185)15,741 
Total $299,023 $(156,926)$142,097 $314,846 $(154,261)$160,585 
Amortization expense for the identifiable intangible assets for the first quarter of fiscal 2025 was $10.7 million, compared to $12.5 million for the prior-year quarter. Estimated amortization expense for the remainder of fiscal 2025 and succeeding years is as follows (in thousands):
Amount
2025 (remaining)$24,093 
202623,384 
202716,754 
202816,245 
202915,387 
Beyond46,234 
Total$142,097 
v3.24.4
Property and Equipment
 3 Months Ended
Dec. 29, 2024
Property, Plant and Equipment [Abstract]  
Property and Equipment Property and Equipment
Property and equipment consisted of the following (in thousands):
As of
 December 29,
2024		September 29,
2024
Equipment, furniture and fixtures$137,639 $139,070 
Leasehold improvements42,322 44,883 
Total property and equipment179,961 183,953 
Accumulated depreciation(112,859)(110,888)
Property and equipment, net$67,102 $73,065 
For the first quarters of fiscal 2025 and 2024, our depreciation expense related to property and equipment was $5.4 million and $7.0 million, respectively.
v3.24.4
Stock Repurchase and Dividends
 3 Months Ended
Dec. 29, 2024
Stock Repurchase And Dividends [Abstract]  
Stock Repurchase and Dividends Stock Repurchase and Dividends
On October 5, 2021, our Board of Directors authorized a stock repurchase program under which we could repurchase up to $400 million of our common stock. In the first quarter of fiscal 2025, we repurchased and settled 600,007 shares with an average price of $41.67 per share for a total cost of $25.0 million in the open market. We did not repurchase any shares of our common stock in the first quarter of fiscal 2024. At December 29, 2024, we had a remaining balance of $322.8 million under our stock repurchase program.
The following table presents dividends declared and paid in the first quarters of fiscal 2025 and 2024:
Declare DateDividend Paid Per ShareRecord DatePayment DateDividend Paid
(in thousands)
November 11, 2024$0.058 November 27, 2024December 13, 2024$15,549 
November 13, 2023$0.052 November 30, 2023December 13, 2023$13,873 

Subsequent Event. On January 27, 2025, our Board of Directors declared a quarterly cash dividend of $0.058 per share payable on February 26, 2025 to stockholders of record as of the close of business on February 12, 2025.
v3.24.4
Leases
 3 Months Ended
Dec. 29, 2024
Leases [Abstract]  
Leases Leases
Our operating leases are primarily for corporate and project office spaces. To a much lesser extent, we have operating leases for vehicles and equipment. Our operating leases have remaining lease terms of one month to ten years, some of which may include options to extend the leases for up to five years.
We determine if an arrangement is a lease at inception. Operating leases are included in "Right-of-use assets, operating leases", "Short-term lease liabilities, operating leases" and "Long-term lease liabilities, operating leases" in the consolidated balance sheets. Our finance leases are primarily for certain IT equipment and are immaterial.
Right-of-use ("ROU") assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, incremental borrowing rates are used based on the information available at commencement date in determining the present value of lease payments. The operating lease ROU asset at the commencement date also includes any lease payments made to the lessor at or before the commencement date and initial direct costs less lease incentives received. Lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for operating lease payments is recognized on a straight-line basis over the lease term.
The components of lease costs are as follows (in thousands):
Three Months Ended
December 29,
2024		December 31,
2023
Operating lease cost$25,916 $24,232 
Sublease income(219)(57)
Total lease cost$25,697 $24,175 
Supplemental cash flow information related to leases is as follows (in thousands):
Three Months Ended
December 29,
2024		December 31,
2023
Operating cash flows for operating leases$18,523 $19,682 
Right-of-use assets obtained in exchange for new operating lease liabilities15,207 9,803 
Supplemental balance sheet and other information related to leases are as follows ($ in thousands):

As of
December 29,
2024		September 29, 2024
Operating leases:
Right-of-use assets$172,080$177,950
Lease liabilities:
Current61,18463,419
Non-current134,759140,095
Total operating lease liabilities$195,943$203,514
Weighted-average remaining lease term:
Operating leases4.4 years4.5 years
Weighted-average discount rate:
Operating leases3.7 %3.6 %
At December 29, 2024, we had $12.7 million of operating leases that have not yet commenced.
A maturity analysis of the future undiscounted cash flows associated with our lease liabilities at December 29, 2024 is as follows (in thousands):
Operating
Leases
2025 (remaining)$51,634 
202653,759 
202741,045 
202823,437 
202918,314 
Beyond24,498 
Total lease payments212,687 
 Less: imputed interest (16,744)
Total present value of lease liabilities$195,943 
v3.24.4
Employee Benefits
 3 Months Ended
Dec. 29, 2024
Retirement Benefits [Abstract]  
Employee Benefits Employee Benefits
In fiscal 2020, the Canadian federal government implemented the Canadian Emergency Wage Subsidy ("CEWS") program in response to the negative impact of the coronavirus disease 2019 pandemic on businesses operating in Canada. Some of our Canadian legal entities qualified for and applied for these CEWS cash benefits to partially offset the impacts of revenue reductions and on-going staffing costs. The $21 million total received was initially recorded in "Other long-term liabilities" until all potential amendments to the qualification criteria, including some that were proposed with retroactive application, were finalized in fiscal 2022. In the first quarter of fiscal 2024, we distributed approximately $10 million to our Canadian employees. The remainder was distributed in the first quarter of fiscal 2025. We have no outstanding applications for further government assistance.
v3.24.4
Stockholders' Equity and Stock Compensation Plans
 3 Months Ended
Dec. 29, 2024
Stockholders' Equity Note [Abstract]  
Stockholders' Equity and Stock Compensation Plans Stockholders’ Equity and Stock Compensation Plans
We recognize the fair value of our stock-based awards as compensation expense on a straight-line basis over the requisite service period in which the award vests. Stock-based compensation expense was $8.1 million and $7.6 million for the first quarters of fiscal 2025 and 2024, respectively. Most of these amounts were included in our selling, general and administrative expenses on our consolidated statements of income. In the first quarter of fiscal 2025, we awarded 236,928 performance share units (“PSUs”) to our non-employee directors and executive officers at an estimated fair value of $49.85 per share on the award date. All PSUs are performance-based and vest, if at all, after the conclusion of the three-year performance period. The number of PSUs that ultimately vest is based 50% on growth in our diluted earnings per share and 50% on our relative total shareholder return over the vesting period. Additionally, we awarded 481,247 restricted stock units (“RSUs”) to our non-employee directors, executive officers and employees at a fair value of $40.29 per share on the award date. All
executive officer and employee RSUs have time-based vesting over a four-year period, and the non-employee director RSUs vest after one year.
v3.24.4
Earnings per Share ("EPS")
 3 Months Ended
Dec. 29, 2024
Earnings Per Share [Abstract]  
Earnings per Share ("EPS") Earnings per Share (“EPS”)
Basic EPS is computed by dividing net income available to common stockholders by the weighted-average common shares outstanding for the period. Diluted EPS is computed by dividing net income by the weighted-average number of common shares outstanding and dilutive potential common shares for the period. Potential common shares include the weighted-average dilutive effects of stock-based awards and shares underlying our Convertible Senior Notes (the "Convertible Notes").
For the first quarter of fiscal 2025, our Convertible Notes, described in Note 15, "Long-Term Debt", had a dilution impact on the dilutive potential common shares, which was calculated using the if-converted method. The dilution impact was due to the price of our common stock exceeding the conversion price. For the first quarter of fiscal 2024, the Convertible Notes had no impact on the calculation of dilutive potential common shares, as the price of our common stock did not exceed the conversion price. The related capped call transactions (the "Capped Call Transactions") for both periods were excluded from the calculation of dilutive potential common shares as their effect is anti-dilutive. For the first quarters of fiscal 2025 and 2024, no options were excluded from the calculation of dilutive potential common shares.
The following table presents the number of weighted-average shares used to compute basic and diluted EPS (in thousands, except per share data):
 Three Months Ended
 December 29,
2024		December 31,
2023
Net income attributable to Tetra Tech$747 $74,972 
Weighted-average common shares outstanding – basic267,854 266,585 
Effect of dilutive stock options and unvested restricted stock2,160 2,105 
Shares issuable assuming conversion of convertible notes1,872 — 
Weighted-average common shares outstanding – diluted271,886 268,690 
Earnings per share attributable to Tetra Tech:  
Basic$— $0.28 
Diluted$— $0.28 
v3.24.4
Income Taxes
 3 Months Ended
Dec. 29, 2024
Income Tax Disclosure [Abstract]  
Income Taxes Income Taxes
The effective tax rates for the first quarters of fiscal 2025 and 2024 were 94.9% and 26.1%, respectively. In the first quarter of fiscal 2025, we recognized a $115 million non-recurring charge related to legal contingencies as described in Note 17, "Commitments and Contingencies". We also determined that $31.3 million of this charge is not tax deductible, which increased our effective tax rate this quarter. Excluding the impact of the legal contingency charge, our effective tax rate was 27.2% in the first quarter of fiscal 2025.
At December 29, 2024 and September 29, 2024, the liability for income taxes associated with uncertain tax positions was $51.1 million and $50.1 million, respectively. It is reasonably possible that the amount of the unrecognized benefit with respect to certain of our unrecognized tax positions may not significantly decrease within the next 12 months. These liabilities represent our current estimates of the additional tax liabilities that we may be assessed when the related audits are concluded. If these audits are resolved in a manner more unfavorable than our current expectations, our additional tax liabilities could be materially higher than the amounts currently recorded resulting in additional tax expense.
v3.24.4
Reportable Segments
 3 Months Ended
Dec. 29, 2024
Segment Reporting [Abstract]  
Reportable Segments Reportable Segments
We manage our operations under two reportable segments. Our GSG reportable segment primarily includes activities with U.S. government clients (federal, state and local) and all activities with development agencies worldwide. Our CIG reportable segment primarily includes activities with U.S. commercial clients and international clients other than development agencies.
GSG provides high-end consulting and engineering services primarily to U.S. government clients (federal, state and local) and international development agencies worldwide. GSG supports U.S. government civilian and defense agencies with services in water, environment, sustainable infrastructure, information technology and disaster management. GSG also provides engineering design services for U.S. based federal and municipal clients, especially in water infrastructure, flood protection and
solid waste. GSG also leads our support for development agencies worldwide, especially in the United States, United Kingdom and Australia.
CIG primarily provides high-end consulting and engineering services to U.S. commercial clients, and international clients inclusive of the commercial and government sectors. CIG supports commercial clients worldwide in renewable energy, industrial, high performance buildings and aerospace markets. CIG also provides sustainable infrastructure and related environmental, engineering and project management services to commercial and local government clients across Canada, in Asia Pacific (primarily Australia and New Zealand), Europe, the United Kingdom and South America (primarily Brazil).
Management evaluates the performance of these reportable segments based upon their respective segment operating income before the effect of amortization expense related to acquisitions, and other unallocated corporate expenses. We account for inter-segment revenues and transfers as if they were to third parties; that is, by applying a negotiated fee onto the costs of the services performed. All significant intercompany balances and transactions are eliminated in consolidation.
Our Corporate Segment's operating income in the first quarter of fiscal 2025, includes a non-recurring charge of $115.0 million related to legal contingencies as described in Note 17, "Commitments and Contingencies". This charge is reported separately as "Legal contingency costs" in our consolidated statement of income for the first quarter of fiscal 2025. We expect to pay this amount within the next 12 months with our cash on hand and by drawing on our credit facility.
The following tables summarize financial information regarding our reportable segments (in thousands):

 Three Months Ended
 December 29,
2024		December 31,
2023
 
Revenue  
GSG$751,782 $575,041 
CIG688,235 669,107 
Elimination of inter-segment revenue(19,456)(15,881)
Total revenue$1,420,561 $1,228,267 
Income from operations  
GSG$83,282 $63,127 
CIG77,677 71,401 
Corporate (1)
(138,433)(23,447)
Total income from operations$22,526 $111,081 
(1)     Includes amortization of intangibles, acquisition and integration expenses, certain legal contingency costs as well as other costs and other income not allocable to our reportable segments.

As of
 December 29,
2024		September 29,
2024
 
Total Assets  
GSG$756,176 $658,493 
CIG1,012,644 1,059,915 
Corporate (1)
2,410,364 2,474,268 
Total assets$4,179,184 $4,192,676 
(1)    Corporate assets consist of intercompany eliminations and assets not allocated to our reportable segments including goodwill, intangible assets, deferred income taxes and certain other assets.
v3.24.4
Fair Value Measurements
 3 Months Ended
Dec. 29, 2024
Fair Value Disclosures [Abstract]  
Fair Value Measurements Fair Value Measurements
We classified our assets and liabilities that were carried at fair value in one of the following categories:
•Level 1: Quoted market prices in active markets for identical assets or liabilities.
•Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data.
•Level 3: Unobservable inputs that are not corroborated by market data.
Contingent Consideration. We measure our contingent earn-out liabilities at fair value on a recurring basis using significant unobservable inputs classified within Level 3 of the fair value hierarchy (see Note 4, "Acquisitions" for further information).
Debt. The fair value of long-term debt under our Credit Facility was determined using the present value of future cash flows based on the borrowing rates currently available for debt with similar terms and maturities (Level 2 measurement, as described in “Critical Accounting Policies and Estimates” in our Annual Report on Form 10-K for the fiscal year ended September 29, 2024). The carrying value of our long-term debt under our Credit Facility approximated fair value at December 29, 2024 and September 29, 2024. At December 29, 2024, we had $325 million in outstanding borrowings under our Amended Credit Agreement, which consisted of $250 million under the New Term Loan Facility and $75 million under the Amended Revolving Credit Facility.
The estimated fair value of our $575 million Convertible Notes, which were used to fund our business acquisitions, working capital needs, dividends, capital expenditures and contingent earn-outs, was determined based on the trading price of the Convertible Notes as of the last trading day of our first quarter of fiscal 2025. We consider the fair value of the Convertible Notes to be a Level 2 measurement as they are not actively traded in markets. The carrying amounts and estimated fair values of the Convertible Notes were approximately $564 million and $673 million, respectively, at December 29, 2024, and $564 million and $743 million, respectively, at September 29, 2024 (see Note 15, "Long-Term Debt" for further information).
v3.24.4
Long-Term Debt
 3 Months Ended
Dec. 29, 2024
Debt Disclosure [Abstract]  
Long-Term Debt Long-Term Debt
Long-term debt consisted of the following (in thousands):
As of
 December 29,
2024		September 29,
2024
Credit facilities$325,000 $250,000 
Convertible notes575,000 575,000 
Debt issuance costs and discount(11,550)(12,366)
Long-term debt$888,450 $812,634 
On August 22, 2023, we issued $575.0 million in Convertible Notes that bear interest at a rate of 2.25% per annum payable in arrears on February 15 and August 15 of each year, beginning on February 15, 2024, and mature on August 15, 2028, unless converted, redeemed or repurchased. Prior to May 15, 2028, the Convertible Notes will be convertible at the option of the holders only upon the occurrence of certain events and during certain periods. Thereafter, the Convertible Notes will be convertible at the option of the holders at any time until the close of business on the second scheduled trading day immediately preceding the maturity date.
The initial conversion rate applicable to the Convertible Notes was 25.4275 shares (5.0855 pre-stock split) of our common stock per $1,000 principal amount of the Convertible Notes, which was equivalent to an initial price of approximately $39.33 per share ($196.64 pre-stock split) of our common stock. The conversion rate is subject to adjustment for certain events, including stock splits and issuance of certain stock dividends on our common stock. At December 29, 2024, the applicable conversion rate was 25.4345 shares of common stock per $1,000 principal amount of the Convertible Notes (equivalent to an adjusted conversion price of approximately $39.32 per share of common stock). Upon conversion, we will pay cash up to the aggregate principal amount of the Convertible Notes to be converted and pay or deliver, as the case may be, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, in respect of the remainder, if any, of our conversion obligation in excess of the aggregate principal amount of the Convertible Notes being converted. In addition, upon the occurrence of a "fundamental change" as defined in the indenture governing the Convertible Notes, holders may require us to repurchase for cash all or any portion of their Convertible Notes at a fundamental change repurchase price equal to 100% of the principal amount of the Convertible Notes to be repurchased plus any accrued and unpaid interest. If certain corporate events occur prior to the maturity date of the Convertible Notes or if we deliver a notice of redemption, we will, in certain circumstances, increase the conversion rate for a holder who elects to convert its Convertible Notes in connection with such event or notice of redemption.
We will not be able to redeem the Convertible Notes prior to August 20, 2026. On or after August 20, 2026, we have the option to redeem for cash all or any portion of the Convertible Notes if the last reported sale price of our common stock is equal to or greater than 130% of the conversion price for a specified period of time at a redemption price equal to 100% of the principal amount of the Convertible Notes to be redeemed, plus any accrued but unpaid interest. In addition, as described in the indenture governing the Convertible Notes, certain events of default including, but not limited to, bankruptcy, insolvency or reorganization, may result in the Convertible Notes becoming due and payable immediately.
Our net proceeds from the offering were approximately $560.5 million after deducting the initial purchasers’ discounts and commissions and offering expenses. We used approximately $51.8 million of the net proceeds to pay the cost of the Capped
Call Transactions described below. We used the remaining net proceeds to repay all $185.0 million principal amount outstanding under our revolving credit facility, the remaining $234.4 million principal amount outstanding under our senior secured term loan due 2027 and approximately $89.4 million principal amount outstanding under our senior secured term loan due 2026.
The Convertible Notes were recorded as a single unit within "Long-term debt" in our consolidated balance sheets as the conversion option within the Convertible Notes was not a derivative that would require bifurcation, and the Convertible Notes did not involve a substantial premium. Transaction costs to issue the Convertible Notes were recorded as direct deductions from the related debt liabilities and are amortized to interest expense using the effective interest method over the terms of the Convertible Notes resulting in an effective annual interest rate of 2.79%.
The net carrying amount of the Convertible Notes was as follows (in thousands):
As of
 December 29,
2024		September 29,
2024
 
Principal$575,000 $575,000 
Unamortized discount and issuance costs(10,737)(11,434)
Net carrying amount$564,263 $563,566 
The following table sets forth the interest expense recognized related to the Convertible Notes (in thousands):
Three Months Ended
 December 29,
2024		December 31,
2023
 
Interest expense$3,234 $3,270 
Amortization of discount and issuance costs697 678 
Total interest expense$3,931 $3,948 
Concurrent with the offering of the Convertible Notes, in August 2023, we entered into the Capped Call Transactions. The Capped Call Transactions are expected generally to reduce the potential dilution of our common stock upon conversion of the Convertible Notes and/or offset any cash payments we elect to make in excess of the principal amount of converted Convertible Notes, as the case may be. If, however, the market price per share of our common stock, as measured under the terms of the Capped Call Transactions, exceeds the cap price of the Capped Call Transactions, there would nevertheless be dilution and/or there would not be an offset of such cash payments, in each case, to the extent that such market price exceeds the cap price of the Capped Call Transactions. The cap price of the Capped Call Transactions was initially $51.91 per share ($259.56 pre-stock split), which represented a premium of 65% over the last reported sale price of our common stock of $31.46 per share ($157.31 pre-stock split) on the NASDAQ Global Select Market on August 17, 2023. The cap price is subject to adjustment for certain events, including stock splits and issuance of certain stock dividends on our common stock. At December 29, 2024, the adjusted cap price was approximately $51.90 per share. We recorded the Capped Call Transactions as separate transactions from the issuance of the Convertible Notes. The cost of $51.8 million incurred to purchase the Capped Call Transactions was recorded as a reduction to additional paid-in capital (net of $12.9 million in deferred taxes) on our consolidated balance sheet as of fiscal 2023 year-end.
On October 26, 2022, we entered into a Third Amended and Restated Credit Agreement that provides for an additional $500 million senior secured term loan facility (the "New Term Loan Facility") increasing our total borrowing capacity to $1.55 billion. On January 23, 2023, we drew the entire amount of the New Term Loan Facility to partially finance the RPS acquisition. The New Term Loan Facility is not subject to any amortization payments of principal and matures in January 2026.
On February 18, 2022, we entered into Amendment No. 2 to Second Amended and Restated Credit Agreement (“Amended Credit Agreement”) with a total borrowing capacity of $1.05 billion that will mature in February 2027. The Amended Credit Agreement is a $750 million senior secured, five-year facility that provides for a $250 million term loan facility (the “Amended Term Loan Facility”) and a $500 million revolving credit facility (the “Amended Revolving Credit Facility”). In addition, the Amended Credit Agreement includes a $300 million accordion feature that allows us to increase the Amended Credit Agreement to $1.05 billion subject to lender approval. The Amended Credit Agreement provides for, among other things, (i) refinance indebtedness under our Credit Agreement dated at July 30, 2018; (ii) finance open market repurchases of common stock, acquisitions, and cash dividends and distributions; and (iii) utilize the proceeds for working capital, capital expenditures and other general corporate purposes. The Amended Credit Agreement provides for a reduction in the interest grid for meeting certain sustainability targets related to the (i) reduction of greenhouse gas emissions through the Company’s projects and operational sustainability initiatives and (ii) improvement of peoples’ lives as a result of the Company’s projects
that provide environmental, social and governance benefits. The Amended Revolving Credit Facility includes a $100 million sublimit for the issuance of standby letters of credit, a $20 million sublimit for swingline loans and a $300 million sublimit for multicurrency borrowings and letters of credit.
The entire Amended Term Loan Facility was drawn on February 18, 2022. We may borrow on the Amended Revolving Credit Facility, at our option, at either (a) a benchmark rate plus a margin that ranges from 1.000% to 1.875% per annum, or (b) a base rate for loans in U.S. dollars (the highest of the U.S. federal funds rate plus 0.50% per annum, the bank’s prime rate or the Secured Overnight Financing Rate ("SOFR") rate plus 1.00%, plus a margin that ranges from 0% to 0.875% per annum. In each case, the applicable margin is based on our Consolidated Leverage Ratio, calculated quarterly. The Amended Term Loan Facility is subject to the same interest rate provisions. The Amended Credit Agreement expires on February 18, 2027, or earlier at our discretion upon payment in full of loans and other obligations. In fiscal 2023, we repaid the Amended Term Loan Facility in full from the Convertible Notes proceeds.
At December 29, 2024, we had $325 million in outstanding borrowings under the Amended Credit Agreement, which was consisted of $250 million under the New Term Loan Facility and $75 million under the Amended Revolving Credit Facility. During the three months ended December 29, 2024, the weighted-average interest rate of the outstanding borrowings under the Amended Credit Agreement was 5.98%. In addition, we had $0.7 million in standby letters of credit under the Amended Credit Agreement. At December 29, 2024, we had $424.3 million of available credit under the Amended Revolving Credit Facility, all of which could be borrowed without a violation of our debt covenants.
The Amended Credit Agreement contains certain affirmative and restrictive covenants, and customary events of default. The financial covenants provide for a maximum Consolidated Leverage Ratio of 3.25 to 1.00 (total funded debt/EBITDA, as defined in the Amended Credit Agreement) and a minimum Consolidated Interest Coverage Ratio of 3.00 to 1.00 (EBITDA/Consolidated Interest Charges, as defined in the Amended Credit Agreement). Our obligations under the Amended Credit Agreement are guaranteed by certain of our domestic subsidiaries and are secured by first priority liens on (i) the equity interests of certain of our subsidiaries, including those subsidiaries that are guarantors or borrowers under the Amended Credit Agreement, and (ii) the accounts receivable, general intangibles and intercompany loans and those of our subsidiaries that are guarantors or borrowers. At December 29, 2024, we were in compliance with these covenants with a consolidated leverage ratio of 1.77x and a consolidated interest coverage ratio of 12.33x.
In addition to the Amended Credit Agreement, we maintain other credit facilities, which may be used for short-term cash advances and bank guarantees. At December 29, 2024, there were no outstanding borrowings under these facilities and the aggregate amount of standby letters of credit outstanding was $40.2 million. As of December 29, 2024, we had no bank overdrafts related to our disbursement bank accounts.
v3.24.4
Reclassifications Out of Accumulated Other Comprehensive Income
 3 Months Ended
Dec. 29, 2024
Equity [Abstract]  
Reclassifications Out of Accumulated Other Comprehensive Income Reclassifications Out of Accumulated Other Comprehensive Income
The accumulated balances and activities for the three months ended December 29, 2024 and December 31, 2023 related to reclassifications out of accumulated other comprehensive income are summarized as follows (in thousands):
 Three Months Ended
 Foreign
Currency
Translation
Adjustments		Net Pension AdjustmentsAccumulated Other Comprehensive (Loss) Income
 
Balance at October 1, 2023$(197,933)$2,638 $(195,295)
Other comprehensive income (loss) before reclassifications63,106 (13)63,093 
Net current-period other comprehensive income (loss)63,106 (13)63,093 
Balance at December 31, 2023$(134,827)$2,625 $(132,202)
Balance at September 29, 2024$(82,813)$3,938 $(78,875)
Other comprehensive loss before reclassifications(108,846)(33)(108,879)
Net current-period other comprehensive loss(108,846)(33)(108,879)
Balance at December 29, 2024$(191,659)$3,905 $(187,754)
v3.24.4
Commitments and Contingencies
 3 Months Ended
Dec. 29, 2024
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies Commitments and Contingencies
We are subject to certain claims and lawsuits typically filed against the consulting and engineering profession, alleging primarily professional errors or omissions. We carry professional liability insurance, subject to certain deductibles and policy limits, against such claims. However, in some actions, parties are seeking damages that exceed our insurance coverage or for which we are not insured. While management does not believe that the resolution of these claims will have a material adverse
effect, individually or in aggregate, on our financial position, results of operations or cash flows, management acknowledges the uncertainty surrounding the ultimate resolution of these matters.
On July 15, 2019, following an initial January 14, 2019 filing, the Civil Division of the United States Attorney's Office of the United States Department of Justice ("the USAO") filed an amended complaint in the intervention of three qui tam actions filed against our wholly-owned subsidiary, Tetra Tech EC, Inc. ("TtEC"), in the U.S. District Court for the Northern District of California ("the Court"). The complaint alleges False Claims Act ("FCA") violations and breach of contract related to TtEC's contracts to perform environmental remediation services at the former Hunters Point Naval Shipyard in San Francisco, California (the "Covered Conduct"). On March 5, 2024, the Court granted the USAO's motion to amend the filing to include additional claims against TtEC under the Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA") and common law.
As we previously disclosed, to explore whether a negotiated resolution was possible, TtEC began engaging in discussions with the USAO during the first quarter of fiscal 2025 regarding a potential resolution of all claims. On January 17, 2025, TtEC entered into a settlement agreement with the United States of America, acting through the USAO and on behalf of the Department of the Navy (collectively, the "United States") and also filed a proposed consent decree with the Court, to resolve this litigation.
Under the terms of the settlement agreement and consent decree, TtEC has agreed to pay the United States $57 million and $40 million for FCA claims and CERCLA claims, respectively (the "Settlement Amounts"), which we expect to pay with cash on hand and by drawing on our credit facility. Upon entry of the consent decree by the Court and the United States' receipt of the Settlement Amounts, the United States will release TtEC from any, and all civil or administrative monetary claims for the Covered Conduct under the civil FCA, the CERCLA, and other specified civil statutes and common law theories of liability.
The consent decree is subject to a number of contingencies that could prevent it from being finalized with its current terms. In particular, and without limitation, (i) the consent decree is required to be lodged with the Court for a period of 30 days for public notice and comment, and the United States has reserved the right to withdraw or withhold its consent if the comments regarding the consent decree disclose facts or considerations that indicate the consent decree is inappropriate, improper or inadequate; and (ii) the Court might determine not to enter the consent decree as currently written or as approved by the United States. There can be no assurance that the contingencies will not preclude entry of the consent decree.
TtEC entered into the settlement agreement and consent decree to avoid delay, uncertainty and expense of protracted litigation. The settlement agreement and consent decree contain no admission of liability by TtEC.
TtEC has initiated litigation with the insurance carrier with which TtEC maintained liability policies regarding the reasonably possible payment or reimbursement of a significant portion of the Settlement Amounts. TtEC can give no assurances as to what portion, if any, of the Settlement Amounts will be recovered from the insurance carrier.
As also previously disclosed, several ancillary claims brought by third-party private plaintiffs arising from the same services provided by TtEC at Hunters Point are also ongoing. The settlement agreement and consent decree do not resolve these ancillary claims.
As a result of the settlement agreement and consent decree with the United States and in connection with discussions regarding the ancillary claims, we recorded a $115.0 million charge to operating income ($97.0 million for the settlement and $18.0 million estimated for the ancillary claims, respectively) in the first quarter of fiscal 2025.
v3.24.4
Related Party Transactions
 3 Months Ended
Dec. 29, 2024
Related Party Transactions [Abstract]  
Related Party Transactions Related Party Transactions
We often provide services to unconsolidated joint ventures. The table below presents revenue and reimbursable costs related to services we provided to our unconsolidated joint ventures (in thousands):
 Three Months Ended
 December 29,
2024		December 31,
2023
 
Revenue$16,479 $18,968 
Related reimbursable costs14,781 17,622 
Our consolidated balance sheets also included the following amounts related to these services (in thousands):
As of
December 29,
2024		September 29, 2024
Accounts receivable, net$13,932 $15,612 
Contract assets1,701 1,625 
Contract liabilities(5,693)(4,237)
v3.24.4
Insider Trading Arrangements
 3 Months Ended
Dec. 29, 2024
Trading Arrangements, by Individual  
Rule 10b5-1 Arrangement Adopted false
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
v3.24.4
Recent Accounting Pronouncements (Policies)
 3 Months Ended
Dec. 29, 2024
Accounting Changes and Error Corrections [Abstract]  
Recent Accounting Pronouncements
In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update (“ASU”) No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which requires that an entity report segment information in accordance with Topic 280, Segment Reporting. The amendments in the ASU are intended to improve reportable segment disclosure requirements primarily through enhanced disclosures about significant segment expenses. The amendments in this ASU are effective for fiscal years beginning after December 15, 2023 (fiscal 2025 year-end for us), and interim periods within fiscal years beginning after December 15, 2024 (first quarter of fiscal 2026 for us). Early adoption is permitted. The adoption of this ASU will not have a material impact on our consolidated financial statements.
In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which requires that an entity, on an annual basis, disclose additional income tax information, primarily related to the rate reconciliation and income taxes paid. The amendments in the ASU are intended to enhance the transparency and decision usefulness of income tax disclosures. The amendments in this ASU are effective for annual periods beginning after December 15, 2024 (fiscal 2026 for us). Early adoption is permitted. The adoption of this ASU will not have a material impact on our consolidated financial statements.
In November 2024, the FASB issued ASU No. 2024-03, Income Statement (Topic 220): Reporting Comprehensive Income. ASU 2024-03 does not change or remove current expense presentation requirements within the consolidated statements of income. However, the amendments require disclosure, on an annual and interim basis, of disaggregated information about certain income statement expense line items within the notes to the consolidated financial statements. The amendments in this update are effective for annual reporting periods beginning after December 15, 2026 (fiscal 2028 for us), and interim reporting periods beginning after December 15, 2027 (first quarter of fiscal 2029 for us). Early adoption is permitted. The adoption of this ASU will not have a material impact on our consolidated financial statements.
In November 2024, the FASB issued ASU No. 2024-04, Debt—Debt with Conversion and Other Options (Subtopic 470-20): Induced Conversions of Convertible Debt Instruments, which clarifies the requirements related to accounting for the settlement of a debt instrument as an induced conversion. The amendments in this update are effective for annual reporting periods beginning after December 15, 2025, including interim periods within those fiscal years (first quarter of fiscal 2027 for us). Early adoption is permitted. We are currently evaluating the impact of this guidance on our consolidated financial statements; however, we do not plan to adopt this ASU before fiscal 2027.
Contract Assets and Contract Liabilities
We invoice customers based on the contractual terms of each contract. However, the timing of revenue recognition may differ from the timing of invoice issuance. Contract assets represent revenue recognized in excess of the amounts for which we have the contractual right to bill our customers. Such amounts are recoverable from customers based upon various measures of performance, including achievement of certain milestones or completion of a contract. In addition, many of our time-and-materials arrangements are billed in arrears pursuant to contract terms that are standard within the industry, resulting in contract assets and/or unbilled receivables being recorded, as revenue is recognized in advance of billings. Contract retentions, included in contract assets, represent amounts withheld by clients until certain conditions are met or the project is completed, which may extend beyond one year.
Contract liabilities consist of billings in excess of revenue recognized. Contract liabilities decrease as we recognize revenue from the satisfaction of the related performance obligation and increase as billings in advance of revenue recognition occur. Contract assets and liabilities are reported in a net position on a contract-by-contract basis at the end of each reporting period. There were no substantial non-current contract assets for the periods presented.
Our RUPO represents a measure of the total dollar value of work to be performed on contracts awarded and in progress. We had $5.4 billion of RUPO at December 29, 2024. Our RUPO increases with awards from new contracts or additions on existing contracts, and decreases as work is performed and revenue is recognized on existing contracts. Our RUPO may also decrease when projects are canceled or modified in scope. We include a contract within our RUPO when the contract is awarded and an agreement on contract terms has been reached.
Although RUPO reflects business that is considered to be firm, cancellations, deferrals or scope adjustments may occur. Our RUPO is adjusted to reflect any known project cancellations, revisions to project scope and cost, foreign currency exchange fluctuations and project deferrals, as appropriate. Our operations and maintenance contracts can generally be terminated by the clients without a substantive financial penalty; therefore, the remaining performance obligations on such contracts are limited to the notice period required for the termination (usually 30, 60, or 90 days).
Accounts Receivable, Net
Billed accounts receivable represent amounts billed to clients that have not been collected. Unbilled accounts receivable, which represent an unconditional right to payment subject only to the passage of time, include unbilled amounts typically resulting from revenue recognized but not yet billed pursuant to contract terms or billed after the period end date. Substantially all of our unbilled receivables at December 29, 2024 are expected to be billed and collected within 12 months. The allowance for doubtful accounts represents amounts that are expected to become uncollectible or unrealizable in the future. We determine an estimated allowance for uncollectible accounts based on management's consideration of trends in the actual and forecasted credit quality of our clients, including delinquency and payment history; type of client, such as a government agency or a commercial sector client; and general economic and industry conditions, which may affect our clients' ability to pay.
Fair Value Measurement
We classified our assets and liabilities that were carried at fair value in one of the following categories:
•Level 1: Quoted market prices in active markets for identical assets or liabilities.
•Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data.
•Level 3: Unobservable inputs that are not corroborated by market data.
Contingent Consideration. We measure our contingent earn-out liabilities at fair value on a recurring basis using significant unobservable inputs classified within Level 3 of the fair value hierarchy (see Note 4, "Acquisitions" for further information).
Debt. The fair value of long-term debt under our Credit Facility was determined using the present value of future cash flows based on the borrowing rates currently available for debt with similar terms and maturities (Level 2 measurement, as described in “Critical Accounting Policies and Estimates” in our Annual Report on Form 10-K for the fiscal year ended September 29, 2024). The carrying value of our long-term debt under our Credit Facility approximated fair value at December 29, 2024 and September 29, 2024.
v3.24.4
Revenue and Contract Balances (Tables)
 3 Months Ended
Dec. 29, 2024
Revenue from Contract with Customer [Abstract]  
Summary of revenue disaggregated by client sector and contract type The following tables present our revenue disaggregated by client sector and contract type (in thousands):
 Three Months Ended
 December 29,
2024		December 31,
2023
Client Sector:  
U.S. federal government (1)
$501,848 $382,076 
U.S. state and local government202,987 150,925 
U.S. commercial233,591 222,430 
International (2)
482,135 472,836 
Total$1,420,561 $1,228,267 
Contract Type:
Fixed-price$519,822 $471,442 
Time-and-materials598,948 549,651 
Cost-plus301,791 207,174 
Total$1,420,561 $1,228,267 
(1)    Includes revenue generated under U.S. federal government contracts performed outside the United States.
(2)    Includes revenue generated from non-U.S. clients, primarily in United Kingdom, Australia and Canada
Summary of net contract assets/liabilities Net contract assets/liabilities consisted of the following (in thousands):
As of
December 29,
2024		September 29, 2024
Contract assets (1)
$122,310 $129,678 
Contract liabilities - current
(359,957)(351,738)
Contract liabilities - non-current (2)
(8,035)— 
Net contract liabilities$(245,682)$(222,060)
(1)    Includes $8.4 million and $7.9 million of contract retentions at December 29, 2024 and September 29, 2024, respectively.
(2)    Reported under "Other non-current liabilities" on our consolidated balance sheet as of December 29,2024.
Components of net accounts receivable
Net accounts receivable consisted of the following (in thousands):
As of
 December 29,
2024		September 29,
2024
Billed$707,357 $707,406 
Unbilled414,778 348,907 
Total accounts receivable1,122,135 1,056,313 
Allowance for doubtful accounts(4,469)(4,852)
Total accounts receivable, net$1,117,666 $1,051,461 
Remaining performance obligation, expected timing
We expect to satisfy our RUPO at December 29, 2024 over the following periods (in thousands):
Amount
Within 12 months$3,673,959 
Beyond 1,717,412 
Total $5,391,371 
v3.24.4
Acquisitions (Tables)
 3 Months Ended
Dec. 29, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]  
Schedule of estimated contingent earn out liabilities
The following table summarizes the changes in the fair value of estimated contingent consideration (in thousands):
Three Months Ended
 December 29,
2024		December 31,
2023
Beginning balance$48,746 $73,422 
Payments of contingent consideration(2,865)(18,862)
Adjustments to fair value recorded in earnings(366)(37)
Interest accretion expense645 471 
Effect of foreign currency exchange rate changes— 610 
Ending balance$46,160 $55,604 
Maximum potential payout at end of period$99,006 $92,253 
v3.24.4
Goodwill and Intangible Assets (Tables)
 3 Months Ended
Dec. 29, 2024
Goodwill and Intangible Assets Disclosure [Abstract]  
Summary of changes in the carrying value of goodwill
The following table summarizes the changes in the carrying value of goodwill by reportable segment (in thousands):
 GSGCIGTotal
Balance at September 29, 2024$750,817 $1,295,752 $2,046,569 
Translation adjustments(4,124)(73,761)(77,885)
Balance at December 29, 2024$746,693 $1,221,991 $1,968,684 
Summary of acquired identifiable intangible assets with finite useful lives
The following table presents the gross amount and accumulated amortization of our acquired identifiable intangible assets with finite useful lives included in “Intangible assets, net” on the consolidated balance sheets ($ in thousands):

As of
 December 29, 2024September 29, 2024
 Weighted-
Average
Remaining Life
(in Years)		Gross
Amount		Accumulated
Amortization		Net AmountGross
Amount		Accumulated
Amortization		Net Amount
Client relations8.0$189,027 $(60,294)$128,733 $198,726 $(57,975)$140,751 
Backlog0.271,647 (70,405)1,242 75,194 (71,101)4,093 
Trade names1.238,349 (26,227)12,122 40,926 (25,185)15,741 
Total $299,023 $(156,926)$142,097 $314,846 $(154,261)$160,585 
Estimated amortization expense for the remainder of the fiscal year and the succeeding years Estimated amortization expense for the remainder of fiscal 2025 and succeeding years is as follows (in thousands):
Amount
2025 (remaining)$24,093 
202623,384 
202716,754 
202816,245 
202915,387 
Beyond46,234 
Total$142,097 
v3.24.4
Property and Equipment (Tables)
 3 Months Ended
Dec. 29, 2024
Property, Plant and Equipment [Abstract]  
Schedule of components of property and equipment
Property and equipment consisted of the following (in thousands):
As of
 December 29,
2024		September 29,
2024
Equipment, furniture and fixtures$137,639 $139,070 
Leasehold improvements42,322 44,883 
Total property and equipment179,961 183,953 
Accumulated depreciation(112,859)(110,888)
Property and equipment, net$67,102 $73,065 
v3.24.4
Stock Repurchase and Dividends (Tables)
 3 Months Ended
Dec. 29, 2024
Stock Repurchase And Dividends [Abstract]  
Summary of dividends declared and paid
The following table presents dividends declared and paid in the first quarters of fiscal 2025 and 2024:
Declare DateDividend Paid Per ShareRecord DatePayment DateDividend Paid
(in thousands)
November 11, 2024$0.058 November 27, 2024December 13, 2024$15,549 
November 13, 2023$0.052 November 30, 2023December 13, 2023$13,873 
v3.24.4
Leases (Tables)
 3 Months Ended
Dec. 29, 2024
Leases [Abstract]  
Summary of components of lease cost
The components of lease costs are as follows (in thousands):
Three Months Ended
December 29,
2024		December 31,
2023
Operating lease cost$25,916 $24,232 
Sublease income(219)(57)
Total lease cost$25,697 $24,175 
Supplemental cash flow information related to leases is as follows (in thousands):
Three Months Ended
December 29,
2024		December 31,
2023
Operating cash flows for operating leases$18,523 $19,682 
Right-of-use assets obtained in exchange for new operating lease liabilities15,207 9,803 
Summary of supplemental balance sheet and other information
Supplemental balance sheet and other information related to leases are as follows ($ in thousands):

As of
December 29,
2024		September 29, 2024
Operating leases:
Right-of-use assets$172,080$177,950
Lease liabilities:
Current61,18463,419
Non-current134,759140,095
Total operating lease liabilities$195,943$203,514
Weighted-average remaining lease term:
Operating leases4.4 years4.5 years
Weighted-average discount rate:
Operating leases3.7 %3.6 %
Summary of maturity of future undiscounted cash flows associated with operating lease liabilities
A maturity analysis of the future undiscounted cash flows associated with our lease liabilities at December 29, 2024 is as follows (in thousands):
Operating
Leases
2025 (remaining)$51,634 
202653,759 
202741,045 
202823,437 
202918,314 
Beyond24,498 
Total lease payments212,687 
 Less: imputed interest (16,744)
Total present value of lease liabilities$195,943 
v3.24.4
Earnings per Share ("EPS") (Tables)
 3 Months Ended
Dec. 29, 2024
Earnings Per Share [Abstract]  
Schedule of number of weighted-average shares used to compute basic and diluted EPS
The following table presents the number of weighted-average shares used to compute basic and diluted EPS (in thousands, except per share data):
 Three Months Ended
 December 29,
2024		December 31,
2023
Net income attributable to Tetra Tech$747 $74,972 
Weighted-average common shares outstanding – basic267,854 266,585 
Effect of dilutive stock options and unvested restricted stock2,160 2,105 
Shares issuable assuming conversion of convertible notes1,872 — 
Weighted-average common shares outstanding – diluted271,886 268,690 
Earnings per share attributable to Tetra Tech:  
Basic$— $0.28 
Diluted$— $0.28 
v3.24.4
Reportable Segments (Tables)
 3 Months Ended
Dec. 29, 2024
Segment Reporting [Abstract]  
Summarized financial information of reportable segments
The following tables summarize financial information regarding our reportable segments (in thousands):

 Three Months Ended
 December 29,
2024		December 31,
2023
 
Revenue  
GSG$751,782 $575,041 
CIG688,235 669,107 
Elimination of inter-segment revenue(19,456)(15,881)
Total revenue$1,420,561 $1,228,267 
Income from operations  
GSG$83,282 $63,127 
CIG77,677 71,401 
Corporate (1)
(138,433)(23,447)
Total income from operations$22,526 $111,081 
(1)     Includes amortization of intangibles, acquisition and integration expenses, certain legal contingency costs as well as other costs and other income not allocable to our reportable segments.

As of
 December 29,
2024		September 29,
2024
 
Total Assets  
GSG$756,176 $658,493 
CIG1,012,644 1,059,915 
Corporate (1)
2,410,364 2,474,268 
Total assets$4,179,184 $4,192,676 
(1)    Corporate assets consist of intercompany eliminations and assets not allocated to our reportable segments including goodwill, intangible assets, deferred income taxes and certain other assets.
v3.24.4
Long-Term Debt (Tables)
 3 Months Ended
Dec. 29, 2024
Debt Disclosure [Abstract]  
Schedule of long-term debt instruments
Long-term debt consisted of the following (in thousands):
As of
 December 29,
2024		September 29,
2024
Credit facilities$325,000 $250,000 
Convertible notes575,000 575,000 
Debt issuance costs and discount(11,550)(12,366)
Long-term debt$888,450 $812,634 
Convertible debt
The net carrying amount of the Convertible Notes was as follows (in thousands):
As of
 December 29,
2024		September 29,
2024
 
Principal$575,000 $575,000 
Unamortized discount and issuance costs(10,737)(11,434)
Net carrying amount$564,263 $563,566 
Interest income and interest expense disclosure
The following table sets forth the interest expense recognized related to the Convertible Notes (in thousands):
Three Months Ended
 December 29,
2024		December 31,
2023
 
Interest expense$3,234 $3,270 
Amortization of discount and issuance costs697 678 
Total interest expense$3,931 $3,948 
v3.24.4
Reclassifications Out of Accumulated Other Comprehensive Income (Tables)
 3 Months Ended
Dec. 29, 2024
Equity [Abstract]  
Summary of reclassifications out of accumulated other comprehensive income
The accumulated balances and activities for the three months ended December 29, 2024 and December 31, 2023 related to reclassifications out of accumulated other comprehensive income are summarized as follows (in thousands):
 Three Months Ended
 Foreign
Currency
Translation
Adjustments		Net Pension AdjustmentsAccumulated Other Comprehensive (Loss) Income
 
Balance at October 1, 2023$(197,933)$2,638 $(195,295)
Other comprehensive income (loss) before reclassifications63,106 (13)63,093 
Net current-period other comprehensive income (loss)63,106 (13)63,093 
Balance at December 31, 2023$(134,827)$2,625 $(132,202)
Balance at September 29, 2024$(82,813)$3,938 $(78,875)
Other comprehensive loss before reclassifications(108,846)(33)(108,879)
Net current-period other comprehensive loss(108,846)(33)(108,879)
Balance at December 29, 2024$(191,659)$3,905 $(187,754)
v3.24.4
Related Party Transactions (Tables)
 3 Months Ended
Dec. 29, 2024
Related Party Transactions [Abstract]  
Schedule of related party transactions
We often provide services to unconsolidated joint ventures. The table below presents revenue and reimbursable costs related to services we provided to our unconsolidated joint ventures (in thousands):
 Three Months Ended
 December 29,
2024		December 31,
2023
 
Revenue$16,479 $18,968 
Related reimbursable costs14,781 17,622 
Our consolidated balance sheets also included the following amounts related to these services (in thousands):
As of
December 29,
2024		September 29, 2024
Accounts receivable, net$13,932 $15,612 
Contract assets1,701 1,625 
Contract liabilities(5,693)(4,237)
v3.24.4
Basis of Presentation (Details)
Jul. 29, 2024
Dec. 29, 2024
$ / shares
Sep. 29, 2024
$ / shares
Organization, Consolidation and Presentation of Financial Statements [Abstract]      
Conversion ratio 5    
Common stock, par value (in dollars per share)   $ 0.01 $ 0.01
v3.24.4
Revenue and Contract Balances - Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Disaggregation of Revenue [Line Items]    
Revenue $ 1,420,561 $ 1,228,267
Fixed-price    
Disaggregation of Revenue [Line Items]    
Revenue 519,822 471,442
Time-and-materials    
Disaggregation of Revenue [Line Items]    
Revenue 598,948 549,651
Cost-plus    
Disaggregation of Revenue [Line Items]    
Revenue 301,791 207,174
U.S. federal government    
Disaggregation of Revenue [Line Items]    
Revenue 501,848 382,076
U.S. state and local government    
Disaggregation of Revenue [Line Items]    
Revenue 202,987 150,925
U.S. commercial    
Disaggregation of Revenue [Line Items]    
Revenue 233,591 222,430
International    
Disaggregation of Revenue [Line Items]    
Revenue $ 482,135 $ 472,836
v3.24.4
Revenue and Contract Balances - Summary of Contract Liabilities/Assets (Details) - USD ($)
$ in Thousands
Dec. 29, 2024
Sep. 29, 2024
Disaggregation of Revenue [Line Items]    
Contract assets $ 122,310 $ 129,678
Contract liabilities - current (359,957) (351,738)
Contract liabilities - non-current (8,035) 0
Net contract liabilities (245,682) (222,060)
Contract Retentions    
Disaggregation of Revenue [Line Items]    
Contract assets $ 8,400 $ 7,900
v3.24.4
Revenue and Contract Balances - Narrative (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Sep. 29, 2024
Revenue from Contract with Customer [Abstract]      
Contract liability revenue recognized during the period $ 116,000 $ 130,000  
Net favorable (unfavorable) revenue and operating income adjustments 2,700 $ 5,700  
Liabilities for anticipated losses 13,200   $ 15,100
Estimated cost to complete the related contracts $ 96,000   $ 101,000
Period for billing and collecting unbilled receivables 12 months    
Remaining unsatisfied performance obligation $ 5,391,371    
Remaining performance obligation, termination notice period one 30 days    
Remaining performance obligation, termination notice period two 60 days    
Remaining performance obligation, termination notice period three 90 days    
v3.24.4
Revenue and Contract Balances - Accounts Receivable, Net (Details) - USD ($)
$ in Thousands
Dec. 29, 2024
Sep. 29, 2024
Revenue from Contract with Customer [Abstract]    
Billed $ 707,357 $ 707,406
Unbilled 414,778 348,907
Total accounts receivable 1,122,135 1,056,313
Allowance for doubtful accounts (4,469) (4,852)
Total accounts receivable, net $ 1,117,666 $ 1,051,461
v3.24.4
Revenue and Contract Balances - Remaining Unsatisfied Performance Obligations (Details)
$ in Thousands
Dec. 29, 2024
USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Remaining unsatisfied performance obligation $ 5,391,371
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-12-30  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Remaining unsatisfied performance obligation $ 3,673,959
Remaining unsatisfied performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-12-30  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Remaining unsatisfied performance obligation $ 1,717,412
Remaining unsatisfied performance obligation, expected timing of satisfaction
v3.24.4
Acquisitions - Narrative (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Sep. 29, 2024
Business Acquisition [Line Items]      
Goodwill $ 1,968,684   $ 2,046,569
Reduction in contingent earn-out liabilities $ 0 $ 0  
Maximum      
Business Acquisition [Line Items]      
Significant unobservable input, earn-out period 5 years    
Maximum | Existing customer contracts      
Business Acquisition [Line Items]      
Useful life of intangible assets 12 years    
Minimum      
Business Acquisition [Line Items]      
Significant unobservable input, earn-out period 3 years    
Minimum | Existing customer contracts      
Business Acquisition [Line Items]      
Useful life of intangible assets 1 year    
LS Technologies      
Business Acquisition [Line Items]      
Total purchase price     120,000
Initial cash payments     93,000
Cash holdback related to tax reserve     4,000
Equity interests issued and issuable     23,000
Net tangible assets     12,000
Intangible assets     23,000
Goodwill     85,000
LS Technologies | Maximum      
Business Acquisition [Line Items]      
Equity interests issued and issuable     $ 60,000
v3.24.4
Acquisitions - Schedule of Estimated Contingent Consideration (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
All acquisitions    
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Aggregate maximum of contingent consideration $ 99,006 $ 92,253
Contingent Consideration    
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 48,746 73,422
Payments of contingent consideration (2,865) (18,862)
Adjustments to fair value recorded in earnings (366) (37)
Interest accretion expense 645 471
Effect of foreign currency exchange rate changes 0 610
Ending balance $ 46,160 $ 55,604
v3.24.4
Goodwill and Intangible Assets - Goodwill (Details)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
USD ($)
Goodwill  
Balance at beginning of the period $ 2,046,569
Translation adjustments (77,885)
Balance at end of the period 1,968,684
GSG  
Goodwill  
Balance at beginning of the period 750,817
Translation adjustments (4,124)
Balance at end of the period 746,693
CIG  
Goodwill  
Balance at beginning of the period 1,295,752
Translation adjustments (73,761)
Balance at end of the period $ 1,221,991
v3.24.4
Goodwill and Intangible Assets - Narrative (Details) - USD ($)
$ in Millions
 3 Months Ended
Jul. 01, 2024
Dec. 29, 2024
Dec. 31, 2023
Sep. 29, 2024
Goodwill [Line Items]        
Impairment of goodwill $ 0.0      
Percentage of excess of fair value over carrying value (less than) 72.00%      
Amortization expense   $ 10.7 $ 12.5  
GSG        
Goodwill [Line Items]        
Gross amounts of goodwill   764.4   $ 768.5
Accumulated impairment   17.7   17.7
CIG        
Goodwill [Line Items]        
Gross amounts of goodwill   1,343.5   1,417.3
Accumulated impairment   $ 121.5   $ 121.5
v3.24.4
Goodwill and Intangible Assets - Gross Amount and Accumulated Amortization of Acquired Finite-lived Intangibles (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Sep. 29, 2024
Finite-Lived Intangible Assets [Line Items]    
Gross Amount $ 299,023 $ 314,846
Accumulated Amortization (156,926) (154,261)
Net Amount $ 142,097 160,585
Client relations    
Finite-Lived Intangible Assets [Line Items]    
Weighted- Average Remaining Life (in Years) 8 years  
Gross Amount $ 189,027 198,726
Accumulated Amortization (60,294) (57,975)
Net Amount $ 128,733 140,751
Backlog    
Finite-Lived Intangible Assets [Line Items]    
Weighted- Average Remaining Life (in Years) 2 months 12 days  
Gross Amount $ 71,647 75,194
Accumulated Amortization (70,405) (71,101)
Net Amount $ 1,242 4,093
Trade names    
Finite-Lived Intangible Assets [Line Items]    
Weighted- Average Remaining Life (in Years) 1 year 2 months 12 days  
Gross Amount $ 38,349 40,926
Accumulated Amortization (26,227) (25,185)
Net Amount $ 12,122 $ 15,741
v3.24.4
Goodwill and Intangible Assets - Estimated Amortization Expense (Details) - USD ($)
$ in Thousands
Dec. 29, 2024
Sep. 29, 2024
Goodwill and Intangible Assets Disclosure [Abstract]    
2025 (remaining) $ 24,093  
2026 23,384  
2027 16,754  
2028 16,245  
2029 15,387  
Beyond 46,234  
Net Amount $ 142,097 $ 160,585
v3.24.4
Property and Equipment (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Sep. 29, 2024
Property, Plant and Equipment [Line Items]      
Property and equipment, gross $ 179,961   $ 183,953
Accumulated depreciation (112,859)   (110,888)
Property and equipment, net 67,102   73,065
Depreciation expense related to property and equipment 5,400 $ 7,000  
Equipment, furniture and fixtures      
Property, Plant and Equipment [Line Items]      
Property and equipment, gross 137,639   139,070
Leasehold improvements      
Property, Plant and Equipment [Line Items]      
Property and equipment, gross $ 42,322   $ 44,883
v3.24.4
Stock Repurchase and Dividends - Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended
Jan. 27, 2025
Dec. 29, 2024
Dec. 31, 2023
Oct. 05, 2021
Equity, Class of Treasury Stock [Line Items]        
Shares repurchased (in shares)   600,007    
Average price (in dollars per share)   $ 41.67    
Total cost   $ 25.0    
Remaining authorized amount under share repurchase program   $ 322.8    
Quarterly cash dividend declared (in dollars per share)   $ 0.058 $ 0.052  
Subsequent Event        
Equity, Class of Treasury Stock [Line Items]        
Quarterly cash dividend declared (in dollars per share) $ 0.058      
October 2021 Stock Repurchase Program        
Equity, Class of Treasury Stock [Line Items]        
Maximum repurchase amount under stock repurchase program       $ 400.0
v3.24.4
Stock Repurchase and Dividends - Schedule of Dividends Declared and Paid (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Stock Repurchase And Dividends [Abstract]    
Dividend Paid Per Share (in dollars per share) $ 0.058 $ 0.052
Dividend Paid $ 15,549 $ 13,873
v3.24.4
Leases - Narrative (Details)
$ in Millions
Dec. 29, 2024
USD ($)
Lessee, Lease, Description [Line Items]  
Renewal term (up to) 5 years
Operating leases, not yet commenced $ 12.7
Minimum  
Lessee, Lease, Description [Line Items]  
Remaining lease term 1 month
Maximum  
Lessee, Lease, Description [Line Items]  
Remaining lease term 10 years
v3.24.4
Leases - Components of Lease Costs (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Leases [Abstract]    
Operating lease cost $ 25,916 $ 24,232
Sublease income (219) (57)
Total lease cost $ 25,697 $ 24,175
v3.24.4
Leases - Supplemental Cash Flow Information (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Leases [Abstract]    
Operating cash flows for operating leases $ 18,523 $ 19,682
Right-of-use assets obtained in exchange for new operating lease liabilities $ 15,207 $ 9,803
v3.24.4
Leases - Supplemental Balance Sheet and Other Information (Details) - USD ($)
$ in Thousands
Dec. 29, 2024
Sep. 29, 2024
Operating leases:    
Right-of-use assets $ 172,080 $ 177,950
Lease liabilities:    
Current 61,184 63,419
Non-current 134,759 140,095
Total operating lease liabilities $ 195,943 $ 203,514
Weighted-average remaining lease term:    
Operating leases 4 years 4 months 24 days 4 years 6 months
Weighted-average discount rate:    
Operating leases 3.70% 3.60%
v3.24.4
Leases - Maturity Analysis of the Future Undiscounted Cash Flows of Operating and Finance Lease Liabilities (Details) - USD ($)
$ in Thousands
Dec. 29, 2024
Sep. 29, 2024
Operating Leases    
2025 (remaining) $ 51,634  
2026 53,759  
2027 41,045  
2028 23,437  
2029 18,314  
Beyond 24,498  
Total lease payments 212,687  
Less: imputed interest (16,744)  
Total present value of lease liabilities $ 195,943 $ 203,514
v3.24.4
Employee Benefits (Details) - USD ($)
$ in Millions
 3 Months Ended
Dec. 31, 2023
Oct. 02, 2022
Retirement Benefits [Abstract]    
Government assistance noncurrent liability   $ 21
Government assistance decrease in liability $ 10  
v3.24.4
Stockholders' Equity and Stock Compensation Plans (Details) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock-based compensation expense $ 8.1 $ 7.6
PSU's    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Awards granted (in shares) 236,928  
Fair value of awards granted (in dollars per share) $ 49.85  
Vesting period 3 years  
Percentage of shares that ultimately vest depending on growth in diluted earnings per share 50.00%  
Percentage of shares that ultimately vest depending on the shareholder return relative to peer group of companies over vesting period 50.00%  
RSU's    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Awards granted (in shares) 481,247  
Fair value of awards granted (in dollars per share) $ 40.29  
RSU's | Executive officers and employees    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period 4 years  
RSU's | Non-employee director    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period 1 year  
v3.24.4
Earnings per Share ("EPS") (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Earnings Per Share [Abstract]    
Net income attributable to Tetra Tech, basic $ 747 $ 74,972
Net income attributable to Tetra Tech, diluted $ 747 $ 74,972
Weighted-average common shares outstanding – basic (in shares) 267,854 266,585
Effect of dilutive stock options and unvested restricted stock (in shares) 2,160 2,105
Shares issuable assuming conversion of convertible notes (in shares) 1,872 0
Weighted-average common stock outstanding – diluted (in shares) 271,886 268,690
Earnings per share attributable to Tetra Tech:    
Basic (in dollars per share) $ 0 $ 0.28
Diluted (in dollars per share) $ 0 $ 0.28
v3.24.4
Income Taxes (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Sep. 29, 2024
Income Tax Disclosure [Abstract]      
Effective tax rate 94.90% 26.10%  
Legal fees $ 115,000 $ 0  
Change in enacted tax rate amount $ 31,300    
Effective income tax rate reconciliation, excluding non-deductible contingency charge, percent 27.20%    
Liability for uncertain tax positions $ 51,100   $ 50,100
v3.24.4
Reportable Segments - Narrative (Details)
$ in Millions
 3 Months Ended
Dec. 29, 2024
USD ($)
segment
Segment Reporting [Abstract]  
Number of reportable segments | segment 2
Legal contingency costs | $ $ 97.0
v3.24.4
Reportable Segments - Summary of Reportable Segments (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Sep. 29, 2024
Segment Reporting Information [Line Items]      
Revenue $ 1,420,561 $ 1,228,267  
Income from operations 22,526 111,081  
Total Assets 4,179,184   $ 4,192,676
Operating segments | GSG      
Segment Reporting Information [Line Items]      
Revenue 751,782 575,041  
Income from operations 83,282 63,127  
Total Assets 756,176   658,493
Operating segments | CIG      
Segment Reporting Information [Line Items]      
Revenue 688,235 669,107  
Income from operations 77,677 71,401  
Total Assets 1,012,644   1,059,915
Elimination of inter-segment revenue      
Segment Reporting Information [Line Items]      
Revenue (19,456) (15,881)  
Corporate      
Segment Reporting Information [Line Items]      
Income from operations (138,433) $ (23,447)  
Total Assets $ 2,410,364   $ 2,474,268
v3.24.4
Fair Value Measurements (Details) - USD ($)
$ in Thousands
Dec. 29, 2024
Sep. 29, 2024
Aug. 22, 2023
Debt Instrument [Line Items]      
Long-term debt $ 888,450 $ 812,634  
Amended Revolving Credit Facility      
Debt Instrument [Line Items]      
Amount outstanding under credit facility 75,000    
Amended Credit Agreement      
Debt Instrument [Line Items]      
Amount outstanding under credit facility 325,000    
Amended Credit Agreement | New Term Loan Facility      
Debt Instrument [Line Items]      
Amount outstanding under credit facility 250,000    
2028 Senior Notes | Convertible Debt      
Debt Instrument [Line Items]      
Principal amount 575,000   $ 575,000
Long-term debt 564,263 563,566  
Convertible debt, estimated fair value $ 673,000 $ 743,000  
v3.24.4
Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($)
$ in Thousands
Dec. 29, 2024
Sep. 29, 2024
Debt Instrument [Line Items]    
Unamortized discount and issuance costs $ (11,550) $ (12,366)
Long-term debt 888,450 812,634
Line of Credit    
Debt Instrument [Line Items]    
Long-term debt, gross 325,000 250,000
Convertible Debt    
Debt Instrument [Line Items]    
Long-term debt, gross $ 575,000 $ 575,000
v3.24.4
Long-Term Debt - Narrative (Details)
 3 Months Ended
Dec. 29, 2024
USD ($)
$ / shares
Sep. 05, 2024
$ / shares
Aug. 22, 2023
USD ($)
$ / shares
Feb. 18, 2022
USD ($)
Dec. 29, 2024
USD ($)
$ / shares
Dec. 31, 2023
USD ($)
Sep. 29, 2024
USD ($)
$ / shares
Oct. 01, 2023
USD ($)
Aug. 17, 2023
$ / shares
Oct. 26, 2022
USD ($)
Line of Credit Facility [Line Items]                    
Repayments of secured debt         $ 15,000,000 $ 60,000,000        
Derivative, cap price per share (in dollars per share) | $ / shares   $ 259.56 $ 51.91       $ 51.90      
Premium over reported sales price, percentage     0.65              
Common stock, reported sales price (in dollars per share) | $ / shares   $ 157.31             $ 31.46  
Deferred tax liabilities $ 24,902,000       24,902,000   $ 30,162,000      
Bank overdrafts 0       0          
Convertible Debt                    
Line of Credit Facility [Line Items]                    
Payments for capped calls     $ 51,800,000              
Deferred tax liabilities               $ 12,900,000    
Revolving Credit Facility                    
Line of Credit Facility [Line Items]                    
Repayments of long-term lines of credit     185,000,000              
Amended Revolving Credit Facility                    
Line of Credit Facility [Line Items]                    
Amount outstanding under credit facility 75,000,000       75,000,000          
Standby Letters of Credit                    
Line of Credit Facility [Line Items]                    
Letters of credit outstanding, amount 40,200,000       40,200,000          
2028 Senior Notes | Convertible Debt                    
Line of Credit Facility [Line Items]                    
Principal amount $ 575,000,000   $ 575,000,000   $ 575,000,000          
Stated interest percentage     2.25%              
Conversion ratio 0.02543450 0.0050855 0.02542750              
Conversion price (in dollars per share) | $ / shares $ 39.32 $ 196.64 $ 39.33   $ 39.32          
Redemption price, percentage     100.00%              
Threshold percentage of stock price trigger     130.00%              
Proceeds from convertible debt     $ 560,500,000              
Interest rate, effective percentage     2.79%              
Term Loan Facility Due 2027                    
Line of Credit Facility [Line Items]                    
Repayments of secured debt     $ 234,400,000              
Term Loan Facility Due 2026                    
Line of Credit Facility [Line Items]                    
Repayments of secured debt     $ 89,400,000              
Amended Credit Agreement                    
Line of Credit Facility [Line Items]                    
Maximum borrowing capacity       $ 750,000,000            
Accordion feature, higher borrowing capacity option       $ 1,050,000,000.00           $ 1,550,000,000
Debt instrument term       5 years            
Accordion feature, increase limit       $ 300,000,000            
Amount outstanding under credit facility $ 325,000,000       $ 325,000,000          
Weighted average interest rate, at point in time 5.98%       5.98%          
Debt covenant, maximum consolidated leverage ratio       3.25            
Debt covenant, maximum consolidated leverage ratio       3.00            
Ratio of indebtedness to net capital 1.77       1.77          
Ratio of consolidated fixed charge coverage ratio 12.33       12.33          
Amended Credit Agreement | Revolving Credit Facility                    
Line of Credit Facility [Line Items]                    
Maximum borrowing capacity       $ 500,000,000            
Remaining borrowing capacity $ 424,300,000       $ 424,300,000          
Amended Credit Agreement | Revolving Credit Facility | Base Rate | Secured Overnight Financing Rate (SOFR)                    
Line of Credit Facility [Line Items]                    
Basis spread on variable rate       1.00%            
Amended Credit Agreement | Revolving Credit Facility | Base Rate | Fed Funds Rate                    
Line of Credit Facility [Line Items]                    
Basis spread on variable rate       0.50%            
Amended Credit Agreement | Revolving Credit Facility | Minimum | Secured Overnight Financing Rate (SOFR)                    
Line of Credit Facility [Line Items]                    
Basis spread on variable rate       1.00%            
Amended Credit Agreement | Revolving Credit Facility | Minimum | Base Rate                    
Line of Credit Facility [Line Items]                    
Basis spread on variable rate       0.00%            
Amended Credit Agreement | Revolving Credit Facility | Maximum | Secured Overnight Financing Rate (SOFR)                    
Line of Credit Facility [Line Items]                    
Basis spread on variable rate       1.875%            
Amended Credit Agreement | Revolving Credit Facility | Maximum | Base Rate                    
Line of Credit Facility [Line Items]                    
Basis spread on variable rate       0.875%            
Amended Credit Agreement | New Term Loan Facility                    
Line of Credit Facility [Line Items]                    
Maximum borrowing capacity                   $ 500,000,000
Amount outstanding under credit facility 250,000,000       250,000,000          
Amended Credit Agreement | Term Loan Facility                    
Line of Credit Facility [Line Items]                    
Maximum borrowing capacity       $ 250,000,000            
Amended Credit Agreement | Standby Letters of Credit                    
Line of Credit Facility [Line Items]                    
Maximum borrowing capacity       100,000,000            
Letters of credit outstanding, amount 700,000       700,000          
Amended Credit Agreement | Swingline Loan                    
Line of Credit Facility [Line Items]                    
Maximum borrowing capacity       20,000,000            
Amended Credit Agreement | Multicurrency Borrowings and Letters of Credit                    
Line of Credit Facility [Line Items]                    
Maximum borrowing capacity       $ 300,000,000            
Other Credit Facilities                    
Line of Credit Facility [Line Items]                    
Amount outstanding under credit facility $ 0       $ 0          
v3.24.4
Long-Term Debt - Net Carrying Amount of Senior Notes (Details) - USD ($)
$ in Thousands
Dec. 29, 2024
Sep. 29, 2024
Debt Instrument [Line Items]    
Unamortized discount and issuance costs $ (11,550) $ (12,366)
Long-term debt 888,450 812,634
Convertible Debt    
Debt Instrument [Line Items]    
Principal 575,000 575,000
2028 Senior Notes | Convertible Debt    
Debt Instrument [Line Items]    
Principal 575,000 575,000
Unamortized discount and issuance costs (10,737) (11,434)
Long-term debt $ 564,263 $ 563,566
v3.24.4
Long-Term Debt - Schedule of Interest Expense (Details) - 2028 Senior Notes - Convertible Debt - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Debt Instrument [Line Items]    
Interest expense $ 3,234 $ 3,270
Amortization of discount and issuance costs 697 678
Total interest expense $ 3,931 $ 3,948
v3.24.4
Reclassifications Out of Accumulated Other Comprehensive Income (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Reclassifications out of accumulated other comprehensive income (loss)    
Beginning balance $ 1,830,413 $ 1,403,506
Other comprehensive (loss) income, net of tax (108,879) 63,093
Ending balance 1,692,019 1,537,687
Accumulated Other Comprehensive (Loss) Income    
Reclassifications out of accumulated other comprehensive income (loss)    
Beginning balance (78,875) (195,295)
Other comprehensive income (loss) before reclassifications (108,879) 63,093
Other comprehensive (loss) income, net of tax (108,879) 63,093
Ending balance (187,754) (132,202)
Foreign Currency Translation Adjustments    
Reclassifications out of accumulated other comprehensive income (loss)    
Beginning balance (82,813) (197,933)
Other comprehensive income (loss) before reclassifications (108,846) 63,106
Other comprehensive (loss) income, net of tax (108,846) 63,106
Ending balance (191,659) (134,827)
Net Pension Adjustments    
Reclassifications out of accumulated other comprehensive income (loss)    
Beginning balance 3,938 2,638
Other comprehensive income (loss) before reclassifications (33) (13)
Other comprehensive (loss) income, net of tax (33) (13)
Ending balance $ 3,905 $ 2,625
v3.24.4
Commitments and Contingencies (Details)
$ in Thousands
 3 Months Ended
Jan. 17, 2025
USD ($)
Dec. 29, 2024
USD ($)
Dec. 31, 2023
USD ($)
Jul. 15, 2019
action
Loss Contingencies [Line Items]        
Number of qui tam actions | action       3
Legal fees   $ 115,000 $ 0  
Legal contingency costs   97,000    
Ancillary claims   $ 18,000    
Forecast | FCA Claims        
Loss Contingencies [Line Items]        
Settlement amount $ 57,000      
Forecast | CERCLA Claims        
Loss Contingencies [Line Items]        
Settlement amount $ 40,000      
v3.24.4
Related Party Transactions (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 29, 2024
Dec. 31, 2023
Sep. 29, 2024
Related Party Transaction [Line Items]      
Revenue $ 1,420,561 $ 1,228,267  
Reimbursable costs 14,781 17,622  
Accounts receivable, net 1,117,666   $ 1,051,461
Contract assets 122,310   129,678
Contract liabilities (359,957)   (351,738)
Related Party      
Related Party Transaction [Line Items]      
Revenue 16,479 $ 18,968  
Accounts receivable, net 13,932   15,612
Contract assets 1,701   1,625
Contract liabilities $ (5,693)   $ (4,237)