AECOM (ACM) 10-Q 7 May 24 2024 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Mar. 31, 2024	May 03, 2024
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	000-52423
Entity Registrant Name	AECOM
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	61-1088522
Entity Address, Address Line One	13355 Noel Road
Entity Address, City or Town	Dallas
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75240
City Area Code	972
Local Phone Number	788-1000
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	ACM
Security Exchange Name	NYSE
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		136,127,400
Entity Central Index Key	0000868857
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
CURRENT ASSETS:
Cash and cash equivalents	$ 910,934	$ 1,030,447
Cash in consolidated joint ventures	274,872	229,759
Total cash and cash equivalents	1,185,806	1,260,206
Accounts receivable-net	2,646,722	2,544,453
Contract assets	1,805,622	1,525,051
Prepaid expenses and other current assets	725,847	730,145
Current assets held for sale	105,091	95,221
Income taxes receivable	28,698	14,435
TOTAL CURRENT ASSETS	6,497,786	6,169,511
PROPERTY AND EQUIPMENT-NET	372,384	382,638
DEFERRED TAX ASSETS-NET	444,957	439,604
INVESTMENTS IN UNCONSOLIDATED JOINT VENTURES	137,422	139,236
GOODWILL	3,446,984	3,418,930
INTANGIBLE ASSETS-NET	16,111	17,769
OTHER NON-CURRENT ASSETS	118,899	218,666
OPERATING LEASE RIGHT-OF-USE ASSETS	422,850	447,044
TOTAL ASSETS	11,457,393	11,233,398
CURRENT LIABILITIES:
Short-term debt	2,914	3,085
Accounts payable	2,304,539	2,190,755
Accrued expenses and other current liabilities	2,385,201	2,287,546
Income taxes payable	36,723	48,161
Contract liabilities	1,267,045	1,188,742
Current liabilities held for sale	51,141	45,625
Current portion of long-term debt	88,552	86,369
TOTAL CURRENT LIABILITIES	6,136,115	5,850,283
OTHER LONG-TERM LIABILITIES	119,797	123,846
OPERATING LEASE LIABILITIES, NON-CURRENT	507,518	548,851
LONG-TERM LIABILITIES HELD FOR SALE	796	792
DEFERRED TAX LIABILITY-NET	16,990	16,960
PENSION BENEFIT OBLIGATIONS	179,464	195,586
LONG-TERM DEBT	2,102,358	2,113,369
TOTAL LIABILITIES	9,063,038	8,849,687
COMMITMENTS AND CONTINGENCIES
AECOM STOCKHOLDERS' EQUITY:
Common stock-authorized, 300,000,000 shares of $0.01 par value as of March 31, 2024 and September 30, 2023; issued and outstanding 135,872,491 and 136,210,883 shares as of March 31, 2024 and September 30, 2023, respectively	1,359	1,362
Additional paid-in capital	4,267,719	4,241,523
Accumulated other comprehensive loss	(909,970)	(926,577)
Accumulated deficits	(1,160,441)	(1,103,976)
TOTAL AECOM STOCKHOLDERS' EQUITY	2,198,667	2,212,332
Noncontrolling interests	195,688	171,379
TOTAL STOCKHOLDERS' EQUITY	2,394,355	2,383,711
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 11,457,393	$ 11,233,398

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2024	Sep. 30, 2023
Consolidated Balance Sheets
Common stock, authorized shares (in shares)	300,000,000	300,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, issued shares (in shares)	135,872,491	136,210,883
Common stock, outstanding shares (in shares)	135,872,491	136,210,883

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Consolidated Statements of Operations
Revenue	$ 3,943,833	$ 3,490,172	$ 7,843,753	$ 6,872,527
Cost of revenue	3,682,659	3,262,078	7,338,609	6,429,445
Gross profit	261,174	228,094	505,144	443,082
Equity in earnings (losses) of joint ventures	19,459	7,456	(9,482)	17,285
General and administrative expenses	(44,686)	(34,147)	(80,410)	(69,759)
Restructuring costs	(35,465)	(3,973)	(51,645)	(41,432)
Income from operations	200,482	197,430	363,607	349,176
Other income	2,622	2,501	5,191	4,485
Interest income	15,422	9,804	27,524	15,690
Interest expense	(47,723)	(42,372)	(88,980)	(79,072)
Income from continuing operations before taxes	170,803	167,363	307,342	290,279
Income tax expense for continuing operations	45,385	41,105	72,043	66,870
Net income from continuing operations	125,418	126,258	235,299	223,409
Net loss from discontinued operations	(109,388)	(41,775)	(110,675)	(42,163)
Net income	16,030	84,483	124,624	181,246
Net income attributable to noncontrolling interests from continuing operations	(14,113)	(8,089)	(27,230)	(17,733)
Net loss (income) attributable to noncontrolling interests from discontinued operations	(910)	221	(1,949)	1,047
Net income attributable to noncontrolling interests	(15,023)	(7,868)	(29,179)	(16,686)
Net income attributable to AECOM from continuing operations	111,305	118,169	208,069	205,676
Net loss attributable to AECOM from discontinued operations	(110,298)	(41,554)	(112,624)	(41,116)
Net income attributable to AECOM	$ 1,007	$ 76,615	$ 95,445	$ 164,560
Net income (loss) attributable to AECOM per share:
Basic continuing operations per share	$ 0.82	$ 0.85	$ 1.53	$ 1.48
Basic discontinued operations per share	(0.81)	(0.30)	(0.83)	(0.29)
Basic earnings per share	0.01	0.55	0.70	1.19
Diluted continuing operations per share	0.81	0.84	1.52	1.46
Diluted discontinued operations per share	(0.80)	(0.29)	(0.82)	(0.29)
Diluted earnings per share	$ 0.01	$ 0.55	$ 0.70	$ 1.17
Weighted average shares outstanding:
Basic (in shares)	136,006	138,927	135,952	138,807
Diluted (in shares)	136,712	140,335	136,907	140,489

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Consolidated Statements of Comprehensive Income
Net income	$ 16,030	$ 84,483	$ 124,624	$ 181,246
Other comprehensive income, net of tax:
Net unrealized gain (loss) on derivatives, net of tax	4,811	(7,564)	(9,401)	(9,381)
Foreign currency translation adjustments	(27,129)	8,627	33,035	86,751
Pension adjustments, net of tax	2,008	(3,672)	(6,990)	(18,519)
Other comprehensive (loss) income, net of tax	(20,310)	(2,609)	16,644	58,851
Comprehensive (loss) income, net of tax	(4,280)	81,874	141,268	240,097
Noncontrolling interests in comprehensive income of consolidated subsidiaries, net of tax	(14,895)	(7,985)	(29,216)	(16,949)
Comprehensive (loss) income attributable to AECOM, net of tax	$ (19,175)	$ 73,889	$ 112,052	$ 223,148

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Parent	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficits	Non-Controlling Interest	Total
BALANCE at Sep. 30, 2022	$ 2,476,654	$ 1,389	$ 4,156,594	$ (979,675)	$ (701,654)	$ 128,725	$ 2,605,379
Increase (Decrease) in Stockholders' Equity
Net income	164,560				164,560	16,686	181,246
Dividends declared	(50,792)				(50,792)		(50,792)
Other comprehensive (loss) income	58,588			58,588		263	58,851
Issuance of stock	17,625	11	17,614				17,625
Repurchases of stock	(96,890)	(13)	(21,872)		(75,005)		(96,890)
Stock-based compensation	24,595		24,595				24,595
Contributions from noncontrolling interests						676	676
Distributions to noncontrolling interests						(3,815)	(3,815)
BALANCE at Mar. 31, 2023	2,594,340	1,387	4,176,931	(921,087)	(662,891)	142,535	2,736,875
BALANCE at Dec. 31, 2022	2,555,634	1,390	4,161,716	(918,361)	(689,111)	137,259	2,692,893
Increase (Decrease) in Stockholders' Equity
Net income	76,615				76,615	7,868	84,483
Dividends declared	(25,394)				(25,394)		(25,394)
Other comprehensive (loss) income	(2,726)			(2,726)		117	(2,609)
Issuance of stock	4,389	1	4,388				4,389
Repurchases of stock	(26,880)	(4)	(1,875)		(25,001)		(26,880)
Stock-based compensation	12,702		12,702				12,702
Contributions from noncontrolling interests						4	4
Distributions to noncontrolling interests						(2,713)	(2,713)
BALANCE at Mar. 31, 2023	2,594,340	1,387	4,176,931	(921,087)	(662,891)	142,535	2,736,875
BALANCE at Sep. 30, 2023	2,212,332	1,362	4,241,523	(926,577)	(1,103,976)	171,379	2,383,711
Increase (Decrease) in Stockholders' Equity
Net income	95,445				95,445	29,179	124,624
Dividends declared	(60,856)				(60,856)		(60,856)
Other comprehensive (loss) income	16,607			16,607		37	16,644
Issuance of stock	16,720	10	16,710				16,720
Repurchases of stock	(112,192)	(13)	(21,125)		(91,054)		(112,192)
Stock-based compensation	30,611		30,611				30,611
Contributions from noncontrolling interests						5,492	5,492
Distributions to noncontrolling interests						(10,399)	(10,399)
BALANCE at Mar. 31, 2024	2,198,667	1,359	4,267,719	(909,970)	(1,160,441)	195,688	2,394,355
BALANCE at Dec. 31, 2023	2,247,296	1,360	4,245,340	(889,788)	(1,109,616)	180,922	2,428,218
Increase (Decrease) in Stockholders' Equity
Net income	1,007				1,007	15,023	16,030
Dividends declared	(30,782)				(30,782)		(30,782)
Other comprehensive (loss) income	(20,182)			(20,182)		(128)	(20,310)
Issuance of stock	5,823	1	5,822				5,823
Repurchases of stock	(20,054)	(2)	998		(21,050)		(20,054)
Stock-based compensation	15,559		15,559				15,559
Contributions from noncontrolling interests						2,616	2,616
Distributions to noncontrolling interests						(2,745)	(2,745)
BALANCE at Mar. 31, 2024	$ 2,198,667	$ 1,359	$ 4,267,719	$ (909,970)	$ (1,160,441)	$ 195,688	$ 2,394,355

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 124,624	$ 181,246
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	87,508	87,786
Equity in losses (earnings) of unconsolidated joint ventures	12,882	(15,545)
Distribution of earnings from unconsolidated joint ventures	12,903	27,126
Non-cash stock compensation	30,611	24,595
Loss on sale of discontinued operations	103,085	40,160
Foreign currency translation	8,125	6,768
Other	(274)	2,615
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable and contract assets	(383,534)	(376,005)
Prepaid expenses and other assets	(5,625)	24,136
Accounts payable	147,593	31,542
Accrued expenses and other current liabilities	84,169	(11,683)
Contract liabilities	78,109	126,035
Other long-term liabilities	(62,758)	(17,321)
Net cash provided by operating activities	237,418	131,455
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments for business acquisition, net of cash acquired	(18,686)
Investment in unconsolidated joint ventures	(29,930)	(26,127)
Return of investment in unconsolidated joint ventures		6,352
Proceeds from sale of investments	3,180	4,786
Proceeds from disposal of property and equipment	249	256
Payments for capital expenditures	(76,734)	(68,819)
Net cash used in investing activities	(121,921)	(83,552)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from borrowings under credit agreements	2,560,032	1,544,751
Repayments of borrowings under credit agreements	(2,590,331)	(1,564,820)
Dividends paid	(55,443)	(46,217)
Proceeds from issuance of common stock	14,840	12,494
Proceeds from exercise of stock options		4,112
Payments to repurchase common stock	(113,086)	(95,191)
Net distributions to noncontrolling interests	(4,907)	(3,139)
Other financing activities	469	646
Net cash used in financing activities	(188,426)	(147,364)
EFFECT OF EXCHANGE RATE CHANGES ON CASH	(168)	3,548
NET DECREASE IN CASH AND CASH EQUIVALENTS	(73,097)	(95,913)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	1,262,152	1,176,772
CASH AND CASH EQUIVALENTS AT END OF PERIOD	1,189,055	1,080,859
LESS CASH AND CASH EQUIVALENTS INCLUDED IN CURRENT ASSETS HELD FOR SALE	(3,249)	(7,344)
CASH AND CASH EQUIVALENTS OF CONTINUING OPERATIONS AT END OF PERIOD	$ 1,185,806	$ 1,073,515

Basis of Presentation

Basis of Presentation	6 Months Ended
	Mar. 31, 2024
Basis of Presentation
Basis of Presentation	1. Basis of Presentation ​ The accompanying consolidated financial statements of AECOM (the Company) are unaudited and, in the opinion of management, include all adjustments, including all normal recurring items necessary for a fair statement of the Company’s financial position and results of operations for the periods presented. All intercompany balances and transactions are eliminated in consolidation. ​ The consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Form 10-K for the fiscal year ended September 30, 2023 (the Annual Report). The accompanying unaudited consolidated financial statements and related notes have been prepared in accordance with generally accepted accounting principles (GAAP) in the United States (U.S.) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. ​ The consolidated financial statements included in this report have been prepared consistently with the accounting policies described in the Annual Report, except as noted, and should be read together with the Annual Report. ​ The results of operations for the three and six months ended March 31, 2024 are not necessarily indicative of the results to be expected for the fiscal year ending September 30, 2024. ​ As discussed in more detail in Note 3, the Company concluded that its self-perform at-risk construction businesses met the criteria for held for sale beginning in the first quarter of fiscal 2020 and met the criteria for discontinued operation classification. As a result, the self-perform at-risk construction businesses are presented in the consolidated statements of operations as discontinued operations for all periods presented. Current and non-current assets and liabilities of these businesses are presented in the consolidated balance sheets as assets and liabilities held for sale. ​ The Company reports its annual results of operations based on 52 or 53-week periods ending on the Friday nearest September 30. The Company reports its quarterly results of operations based on periods ending on the Friday nearest December 31, March 31, and June 30. For clarity of presentation, all periods are presented as if the periods ended on September 30, December 31, March 31, and June 30.

New Accounting Pronouncements a

New Accounting Pronouncements and Changes in Accounting	6 Months Ended
	Mar. 31, 2024
New Accounting Pronouncements and Changes in Accounting
New Accounting Pronouncements and Changes in Accounting	2. New Accounting Pronouncements and Changes in Accounting ​ In November 2023, the Financial Accounting Standards Board (FASB) amended the guidance of Accounting Standards Codification (ASC) 280, Segment Reporting ​ In December 2023, the FASB issued ASU 2023-09, Income Taxes

Discontinued Operations, Goodwi

Discontinued Operations, Goodwill, and Intangible Assets	6 Months Ended
	Mar. 31, 2024
Discontinued Operations, Goodwill, and Intangible Assets
Discontinued Operations, Goodwill, and Intangible Assets	3. Discontinued Operations, Goodwill and Intangible Assets ​ In the first quarter of fiscal 2020, management approved a plan to dispose of via sale the Company’s self-perform at-risk construction businesses. These businesses include the Company’s civil infrastructure, power, and oil and gas construction businesses that were previously reported in the Company’s Construction Services segment. After consideration of the relevant facts, the Company concluded the assets and liabilities of its self-perform at-risk construction businesses met the criteria for classification as held for sale. The Company concluded the actual and proposed disposal activities represented a strategic shift that would have a major effect on the Company’s operations and financial results and qualified for presentation as discontinued operations in accordance with FASB ASC 205-20. Accordingly, the financial results of the self-perform at-risk construction businesses are presented in the Consolidated Statement of Operations as discontinued operations for all periods presented. Current and non-current assets and liabilities of these businesses not sold as of the balance sheet date are presented in the Consolidated Balance Sheets as assets and liabilities held for sale for both periods presented. ​ The Company completed the sale of its power and oil and gas construction businesses in fiscal 2021 and fiscal 2022, respectively. The Company completed the sale of its civil infrastructure construction business to affiliates of Oroco Capital in the second quarter of fiscal 2021. In the second quarter of fiscal 2024 and 2023, the Company recorded losses related to revised estimates of its contingent consideration receivable recognized in its civil infrastructure construction business of $103.1 million and $38.9 million, respectively. ​ The following table represents summarized balance sheet information of assets and liabilities held for sale (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ September 30, ​ 2024 2023 ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 3.3 ​ $ 1.9 Receivables and contract assets ​ 101.3 ​ ​ 93.3 Other ​ 0.5 ​ ​ — Current assets held for sale ​ $ 105.1 ​ $ 95.2 ​ ​ ​ ​ ​ ​ ​ Property and equipment, net ​ $ 15.8 ​ $ 14.2 Write-down of assets to fair value less cost to sell ​ ​ (15.8) ​ ​ (14.2) Non-current assets held for sale ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ Accounts payable and accrued expenses ​ $ 51.1 ​ ​ 45.6 Current liabilities held for sale ​ $ 51.1 ​ $ 45.6 ​ ​ ​ ​ ​ ​ ​ Long-term liabilities held for sale ​ $ 0.8 ​ $ 0.8 ​ The following table represents summarized income statement information of discontinued operations (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended Six months ended ​ ​ March 31, ​ March 31, March 31, ​ March 31, ​ 2024 2023 2024 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 46.5 ​ $ 58.8 ​ $ 101.1 ​ $ 100.5 Cost of revenue ​ 45.0 ​ ​ 62.1 ​ ​ 97.7 ​ ​ 102.4 Gross profit (loss) ​ 1.5 ​ ​ (3.3) ​ ​ 3.4 ​ ​ (1.9) Equity in earnings of joint ventures ​ (3.4) ​ ​ — ​ ​ (3.4) ​ ​ (1.7) Loss on disposal activities ​ ​ (109.6) ​ ​ (40.2) ​ ​ (113.1) ​ ​ (40.2) Transaction costs ​ ​ (0.2) ​ ​ — ​ ​ (0.2) ​ ​ (0.2) Loss from operations ​ (111.7) ​ ​ (43.5) ​ ​ (113.3) ​ ​ (44.0) Other loss ​ (0.5) ​ ​ — ​ ​ (1.1) ​ ​ — Loss before taxes ​ (112.2) ​ ​ (43.5) ​ ​ (114.4) ​ ​ (44.0) Income tax benefit ​ (2.8) ​ ​ (1.7) ​ ​ (3.7) ​ ​ (1.8) Net loss from discontinuing operations ​ $ (109.4) ​ $ (41.8) ​ $ (110.7) ​ $ (42.2) ​ The significant components included in our Consolidated Statement of Cash Flows for the discontinued operations are as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended Six months ended ​ ​ March 31, March 31, ​ March 31, March 31, ​ 2024 ​ 2023 2024 ​ 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Payments for capital expenditures ​ $ 2.1 ​ $ 0.5 ​ $ 2.1 ​ $ 4.5 ​ The Company completed one acquisition in the first quarter of fiscal 2024. The changes in the carrying value of goodwill by reportable segment for the six months ended March 31, 2024 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ Exchange ​ ​ ​ ​ March 31, ​ 2023 Impact Acquired 2024 ​ ​ (in millions) Americas ​ $ 2,614.0 ​ $ 0.5 ​ $ 12.2 ​ $ 2,626.7 International ​ 804.9 ​ ​ 15.4 ​ ​ — ​ ​ 820.3 Total ​ $ 3,418.9 ​ $ 15.9 ​ $ 12.2 ​ $ 3,447.0 ​ The gross amounts and accumulated amortization of the Company’s acquired identifiable intangible assets with finite useful lives as of March 31, 2024 and September 30, 2023, included in intangible assets—net, in the accompanying consolidated balance sheets, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 ​ September 30, 2023 ​ ​ ​ ​ Gross ​ Accumulated ​ Intangible ​ Gross ​ Accumulated ​ Intangible ​ Amortization ​ Amount Amortization Assets, Net Amount Amortization Assets, Net Period ​ ​ (in millions) ​ (years) Backlog and Customer relationships ​ $ 671.5 ​ $ (655.4) ​ $ 16.1 ​ $ 663.8 ​ $ (646.0) ​ $ 17.8 ​ 1 - 11 ​ Amortization expense of acquired intangible assets included within cost of revenue was $9.4 million and $9.3 million for the six months ended March 31, 2024 and 2023, respectively. The following table presents estimated amortization expense of existing intangible assets for the remainder of fiscal 2024 and for the succeeding years: ​ ​ ​ ​ ​ Fiscal Year (in millions) 2024 (six months remaining) ​ $ 9.2 2025 ​ 2.1 2026 ​ 1.5 2027 ​ 1.5 2028 ​ ​ 1.5 Thereafter ​ 0.3 Total ​ $ 16.1 ​

Revenue Recognition

Revenue Recognition	6 Months Ended
	Mar. 31, 2024
Revenue Recognition.
Revenue Recognition	4. Revenue Recognition ​ The Company follows accounting principles for recognizing revenue upon the transfer of control of promised goods or services to customers, in an amount that reflects the expected consideration received in exchange for those goods or services. The Company generally recognizes revenues over time as performance obligations are satisfied. The Company generally measures its progress to completion using an input measure of total costs incurred divided by total costs expected to be incurred, which it believes to be the best measure of progress towards completion of the performance obligation. In the course of providing its services, the Company routinely subcontracts for services and incurs other direct costs on behalf of its clients. These costs are passed through to clients and, in accordance with GAAP, are included in the Company’s revenue and cost of revenue. These pass-through revenues for the six months ended March 31, 2024 and 2023 were $4.3 billion and $3.6 billion, respectively. ​ Recognition of revenue and profit is dependent upon a number of factors, including the accuracy of a variety of estimates made at the balance sheet date, such as engineering progress, material quantities, the achievement of milestones, penalty provisions, labor productivity and cost estimates. Additionally, the Company is required to make estimates for the amount of consideration to be received, including bonuses, awards, incentive fees, claims, unpriced change orders, penalties, and liquidated damages. Variable consideration is included in the estimate of the transaction price only to the extent that a significant reversal would not be probable. Management continuously monitors factors that may affect the quality of its estimates, and material changes in estimates are disclosed accordingly. Costs attributable to claims are treated as costs of contract performance as incurred. ​ The following summarizes the Company’s major contract types: ​ Cost Reimbursable Contracts ​ Cost reimbursable contracts include cost-plus fixed fee, cost-plus fixed rate, and time-and-materials price contracts. Under cost-plus contracts, the Company charges clients for its costs, including both direct and indirect costs, plus a negotiated fee or rate. The Company recognizes revenue based on actual direct costs incurred and the applicable fixed rate or portion of the fixed fee earned as of the balance sheet date. Under time-and-materials price contracts, the Company negotiates hourly billing rates and charges its clients based on the actual time that it expends on a project. In addition, clients reimburse the Company for materials and other direct incidental expenditures incurred in connection with its performance under the contract. The Company may apply a practical expedient to recognize revenue in the amount in which it has the right to invoice if its right to consideration is equal to the value of performance completed to date. ​ Guaranteed Maximum Price Contracts (GMP) ​ GMP contracts share many of the same contract provisions as cost-plus and fixed-price contracts. As with cost-plus contracts, clients are provided a disclosure of all the project costs, and a lump sum or percentage fee is separately identified. The Company provides clients with a guaranteed price for the overall project (adjusted for change orders issued by clients) and a schedule including the expected completion date. Cost overruns or costs associated with project delays in completion could generally be the Company’s responsibility. For many of the Company’s commercial or residential GMP contracts, the final price is generally not established until the Company has subcontracted a substantial percentage of the trade contracts with terms consistent with the master contract, and it has negotiated additional contractual limitations, such as waivers of consequential damages as well as aggregate caps on liabilities and liquidated damages. Revenue is recognized for GMP contracts as project costs are incurred relative to total estimated project costs. ​ Fixed-Price Contracts ​ Fixed-price contracts include both lump-sum and fixed-unit price contracts. Under lump-sum contracts, the Company performs all the work under the contract for a specified fee. Lump-sum contracts are typically subject to price adjustments if the scope of the project changes or unforeseen conditions arise. Under fixed-unit price contracts, the Company performs a number of units of work at an agreed price per unit with the total payment under the contract determined by the actual number of units delivered. Revenue is recognized for fixed-price contracts using the input method measured on a cost-to-cost basis as the Company believes this is the best measure of progress towards completion. ​ The following tables present the Company’s revenues disaggregated by revenue sources: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ March 31, ​ March 31, ​ March 31, ​ March 31, ​ 2024 2023 2024 2023 ​ (in millions) Cost reimbursable ​ $ 1,605.1 ​ $ 1,511.3 ​ $ 3,222.3 ​ $ 3,026.2 Guaranteed maximum price ​ ​ 1,420.7 ​ ​ 1,151.0 ​ ​ 2,835.6 ​ ​ 2,239.2 Fixed-price ​ ​ 918.1 ​ ​ 827.8 ​ ​ 1,785.9 ​ ​ 1,607.1 Total revenue ​ $ 3,943.9 ​ $ 3,490.1 ​ $ 7,843.8 ​ $ 6,872.5 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ March 31, ​ March 31, ​ March 31, ​ March 31, ​ 2024 2023 2024 2023 ​ (in millions) Americas ​ $ 3,039.1 ​ $ 2,630.3 ​ $ 6,077.9 ​ $ 5,209.9 Europe, Middle East, India, Africa ​ ​ 619.8 ​ ​ 494.1 ​ ​ 1,115.2 ​ ​ 942.1 Asia-Australia-Pacific ​ ​ 285.0 ​ ​ 365.7 ​ ​ 650.7 ​ ​ 720.5 Total revenue ​ $ 3,943.9 ​ $ 3,490.1 ​ $ 7,843.8 ​ $ 6,872.5 ​ As of March 31, 2024, the Company had allocated $21.4 billion of transaction price to unsatisfied or partially satisfied performance obligations, of which approximately 55% is expected to be satisfied within the next twelve months. The majority of remaining performance obligation after the first 12 months are expected to be recognized over a two-year period. ​ Contract liabilities represent amounts billed to clients in excess of revenue recognized to date. The Company recognized revenue of $685.3 million and $696.9 million during the six months ended March 31, 2024 and 2023, respectively, that was included in contract liabilities as of September 30, 2023 and 2022, respectively. ​ The Company’s timing of revenue recognition may not be consistent with its rights to bill and collect cash from its clients. Those rights are generally dependent upon advance billing terms, milestone billings based on the completion of certain phases of work or when services are performed. The Company’s accounts receivables represent amounts billed to clients that have yet to be collected and represent an unconditional right to cash from its clients. Contract assets represent the amount of contract revenue recognized but not yet billed pursuant to contract terms or accounts billed after the balance sheet date. Contract liabilities represent billings as of the balance sheet date, as allowed under the terms of a contract, but not yet recognized as contract revenue pursuant to the Company’s revenue recognition policy. ​ Net accounts receivable consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ September 30, ​ ​ 2024 2023 ​ ​ (in millions) Billed ​ $ 2,125.4 ​ $ 2,122.2 Contract retentions ​ 602.8 ​ ​ 516.5 Total accounts receivable—gross ​ 2,728.2 ​ ​ 2,638.7 Allowance for doubtful accounts and credit losses ​ (81.5) ​ ​ (94.2) Total accounts receivable—net ​ $ 2,646.7 ​ $ 2,544.5 ​ Substantially all contract assets as of March 31, 2024 and September 30, 2023 are expected to be billed and collected within twelve months, except for claims. Significant claims recorded in contract assets and other non-current assets were approximately $170 million and $160 million as of March 31, 2024 and September 30, 2023, respectively. The asset related to the Deactivation, Demolition, and Removal Project retained from the MS Purchaser as defined in and discussed in Note 15 is presented in prepaid expense and other current assets from continuing operations in the Consolidated Balance Sheet. Contract retentions represent amounts invoiced to clients where payments have been withheld from progress payments until the contracted work has been completed and approved by the client but nonetheless represent an unconditional right to cash. ​ The Company considers a broad range of information to estimate expected credit losses including the related ages of past due balances, projections of credit losses based on historical trends, and collection history and credit quality of its clients. Negative macroeconomic trends or delays in payment of outstanding receivables could result in an increase in the estimated credit losses. ​ No single client accounted for more than 10% of the Company’s outstanding receivables at March 31, 2024 and September 30, 2023. ​ The Company sold trade receivables to financial institutions, of which $291.9 million and $291.0 million were outstanding as of March 31, 2024 and September 30, 2023, respectively. The Company does not retain financial or legal obligations for these receivables that would result in material losses. The Company’s ongoing involvement is limited to the remittance of customer payments to the financial institutions with respect to the sold trade receivables.

Joint Ventures and Variable Int

Joint Ventures and Variable Interest Entities	6 Months Ended
	Mar. 31, 2024
Joint Ventures and Variable Interest Entities
Joint Ventures and Variable Interest Entities	5. Joint Ventures and Variable Interest Entities ​ The Company’s joint ventures provide architecture, engineering, program management, construction management, and manages investments in real estate projects. Joint ventures, the combination of two or more partners, are generally formed for a specific project. Management of the joint venture is typically controlled by a joint venture executive committee, comprised of representatives from the joint venture partners. The joint venture executive committee normally provides management oversight and controls decisions which could have a significant impact on the joint venture. ​ Some of the Company’s joint ventures have no employees and minimal operating expenses. For these joint ventures, the Company’s employees perform work for the joint venture, which is then billed to a third-party customer by the joint venture. These joint ventures function as pass-through entities to bill the third-party customer. For consolidated joint ventures of this type, the Company records the entire amount of the services performed and the costs associated with these services, including the services provided by the other joint venture partners, in the Company’s result of operations. For certain of these joint ventures where a fee is added by an unconsolidated joint venture to client billings, the Company’s portion of that fee is recorded in equity in earnings of joint ventures. ​ The Company also has joint ventures that have their own employees and operating expenses, and to which the Company generally makes a capital contribution. The Company accounts for these joint ventures either as consolidated entities or equity method investments based on the criteria further discussed below. ​ The Company follows guidance on the consolidation of variable interest entities (VIEs) that requires companies to utilize a qualitative approach to determine whether it is the primary beneficiary of a VIE. The process for identifying the primary beneficiary of a VIE requires consideration of the factors that indicate a party has the power to direct the activities that most significantly impact the joint venture’s economic performance, including powers granted to the joint venture’s program manager, powers contained in the joint venture governing board and, to a certain extent, a company’s economic interest in the joint venture. The Company analyzes its joint ventures and classifies them as either: ​ ● a VIE that must be consolidated because the Company is the primary beneficiary or the joint venture is not a VIE and the Company holds the majority voting interest with no significant participative rights available to the other partners; or ​ ● a VIE that does not require consolidation and is treated as an equity method investment because the Company is not the primary beneficiary or the joint venture is not a VIE and the Company does not hold the majority voting interest. ​ As part of the above analysis, if it is determined that the Company has the power to direct the activities that most significantly impact the joint venture’s economic performance, the Company considers whether or not it has the obligation to absorb losses or rights to receive benefits of the VIE that could potentially be significant to the VIE. ​ Contractually required support provided to the Company’s joint ventures is further discussed in Note 15. ​ Summary of financial information of the consolidated joint ventures is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ ​ ​ ​ 2024 ​ September 30, ​ ​ (unaudited) ​ 2023 ​ ​ (in millions) Current assets ​ $ 970.0 ​ $ 806.3 Non-current assets ​ 84.5 ​ ​ 75.9 Total assets ​ $ 1,054.5 ​ $ 882.2 ​ ​ ​ ​ ​ ​ ​ Current liabilities ​ $ 878.4 ​ $ 779.6 Non-current liabilities ​ 1.5 ​ ​ 1.5 Total liabilities ​ 879.9 ​ ​ 781.1 Total AECOM deficit ​ (3.7) ​ ​ (54.9) Noncontrolling interests ​ 178.3 ​ ​ 156.0 Total owners’ equity ​ 174.6 ​ ​ 101.1 Total liabilities and owners’ equity ​ $ 1,054.5 ​ $ 882.2 ​ Total revenue of the consolidated joint ventures was $1,171.4 million and $941.7 million for the six months ended March 31, 2024 and 2023, respectively. The assets of the Company’s consolidated joint ventures are restricted for use only by the particular joint venture and are not available for the general operations of the Company. ​ Summary of unaudited financial information of the unconsolidated joint ventures, as derived from their unaudited financial statements, was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ September 30, ​ 2024 2023 ​ ​ (in millions) Current assets ​ $ 1,201.8 ​ $ 1,177.4 Non-current assets ​ 1,052.8 ​ ​ 996.3 Total assets ​ $ 2,254.6 ​ $ 2,173.7 ​ ​ ​ ​ ​ ​ ​ Current liabilities ​ $ 624.7 ​ $ 605.9 Non-current liabilities ​ 434.2 ​ ​ 441.7 Total liabilities ​ 1,058.9 ​ ​ 1,047.6 Joint ventures’ equity ​ 1,195.7 ​ ​ 1,126.1 Total liabilities and joint ventures’ equity ​ $ 2,254.6 ​ $ 2,173.7 ​ ​ ​ ​ ​ ​ AECOM’s investment in unconsolidated joint ventures ​ $ 137.4 ​ $ 139.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ March 31, ​ March 31, ​ 2024 2023 ​ ​ (in millions) Revenue ​ $ 696.4 ​ $ 642.1 Cost of revenue ​ 645.9 ​ ​ 586.9 Gross profit ​ $ 50.5 ​ $ 55.2 Net income ​ $ 50.7 ​ $ 51.9 ​ Summary of AECOM’s equity in earnings of unconsolidated joint ventures is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ March 31, March 31, ​ 2024 2023 ​ (in millions) Pass-through joint ventures ​ $ 17.6 ​ $ 14.5 Other joint ventures ​ (27.1) ​ ​ 2.8 Total ​ $ (9.5) ​ $ 17.3 ​

Pension Benefit Obligations

Pension Benefit Obligations	6 Months Ended
	Mar. 31, 2024
Pension Benefit Obligations
Pension Benefit Obligations	6. Pension Benefit Obligations ​ In the U.S., the Company sponsors various qualified defined benefit pension plans. Benefits under these plans generally are based on the employee’s years of creditable service and compensation; however, all U.S. defined benefit plans are closed to new participants and have frozen accruals. ​ The Company also sponsors various non-qualified plans in the U.S.; all of these plans are frozen. Outside the U.S., the Company sponsors various pension plans, which are appropriate to the country in which the Company operates, some of which are government mandated. ​ The components of net periodic benefit cost other than the service cost component are included in other income in the consolidated statement of operations. The following table details the components of net periodic benefit cost for the Company’s pension plans for the three and six months ended March 31, 2024 and 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ March 31, 2024 ​ March 31, 2023 ​ March 31, 2024 ​ March 31, 2023 ​ U.S. Int’l U.S. Int’l U.S. Int’l U.S. Int’l ​ ​ (in millions) Components of net periodic benefit cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service costs ​ $ — ​ $ — ​ $ — ​ $ 0.1 ​ $ — ​ $ 0.1 ​ $ — ​ $ 0.2 Interest cost on projected benefit obligation ​ 2.5 ​ ​ 10.9 ​ ​ 2.4 ​ ​ 11.9 ​ ​ 4.9 ​ ​ 21.6 ​ ​ 4.9 ​ ​ 23.4 Expected return on plan assets ​ (1.4) ​ ​ (14.2) ​ ​ (1.4) ​ ​ (15.1) ​ ​ (2.8) ​ ​ (28.3) ​ ​ (2.9) ​ ​ (29.8) Amortization of net loss (gain) ​ 0.7 ​ ​ (0.6) ​ ​ 0.8 ​ ​ (0.2) ​ ​ 1.5 ​ ​ (1.2) ​ ​ 1.7 ​ ​ (0.3) Net periodic benefit cost (credit) ​ $ 1.8 ​ $ (3.9) ​ $ 1.8 ​ $ (3.3) ​ $ 3.6 ​ $ (7.8) ​ $ 3.7 ​ $ (6.5) ​ The total amounts of employer contributions paid for the six months ended March 31, 2024 were $4.4 million for U.S. plans and $13.1 million for non-U.S. plans. The expected remaining scheduled annual employer contributions for the fiscal year ending September 30, 2024 are $8.5 million for U.S. plans and $12.6 million for non-U.S. plans.

Debt

Debt	6 Months Ended
	Mar. 31, 2024
Debt
Debt	7. Debt Debt consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ September 30, ​ 2024 2023 ​ ​ (in millions) Credit Agreement ​ $ 1,105.1 ​ $ 1,119.8 2027 Senior Notes ​ ​ 997.3 ​ ​ 997.3 Other debt ​ 103.5 ​ ​ 100.2 Total debt ​ 2,205.9 ​ ​ 2,217.3 Less: Current portion of debt and short-term borrowings ​ (91.5) ​ ​ (89.5) Less: Unamortized debt issuance costs ​ ​ (12.0) ​ ​ (14.4) Long-term debt ​ $ 2,102.4 ​ $ 2,113.4 ​ The following table presents, in millions, scheduled maturities of the Company’s debt as of March 31, 2024: ​ ​ ​ ​ ​ Fiscal Year ​ ​ 2024 (six months remaining) ​ $ 63.3 2025 ​ ​ 54.4 2026 ​ ​ 417.3 2027 ​ ​ 1,013.7 2028 ​ ​ 657.2 Total ​ $ 2,205.9 ​ Credit Agreement ​ On February 8, 2021, the Company entered into the 2021 Refinancing Amendment to Credit Agreement (as amended, modified or otherwise supplemented, the “Credit Agreement”), pursuant to which the Company amended and restated its Syndicated Facility Agreement, dated as of October 17, 2014 (as amended prior to February 8, 2021, the “Original Credit Agreement”), between the Company, as borrower, Bank of America, N.A., as administrative agent, and other parties thereto. At the time of amendment, the Credit Agreement consisted of a $1,150,000,000 revolving credit facility (the “Original Revolving Credit Facility”) and a $246,968,737.50 term loan A facility (the “Original Term A Facility,”), each of which would have matured on February 8, 2026. The proceeds of the Original Revolving Credit Facility and the Original Term A Loan facility borrowed on February 8, 2021 were used to refinance the existing revolving credit facility and the existing term loan facility under the Original Credit Agreement and to pay related fees and expenses. ​ On April 13, 2021, the Company entered into Amendment No. 10 to Credit Agreement, pursuant to which the lenders thereunder provided a secured term B credit facility (the “Original Term B Facility,” and together with the Original Term A Facility and Original Revolving Credit Facility, the “Original Credit Facilities”) to the Company in an aggregate principal amount of $700,000,000. The Original Term B Facility would have matured on April 13, 2028. The proceeds of the Original Term B Facility were used to fund the purchase price, fees and expenses in connection with the Company’s cash tender offer to purchase up to $700,000,000 aggregate purchase price (not including any accrued and unpaid interest) of its outstanding 5.875% Senior Notes due 2024. ​ On June 25, 2021, the Company entered into Amendment No. 11 to Credit Agreement, pursuant to which lenders thereunder provided the Company an additional $215,000,000 in aggregate principal amount under the Original Term A Facility. The Company used the net proceeds from the increase in the Original Term A Facility (together with cash on hand), to (i) redeem all of the Company’s remaining 5.875% Senior Notes due 2024 and (ii) pay fees and expenses related to such redemption. ​ On May 23, 2023, the Company entered into Amendment No. 12 to Credit Agreement, pursuant to which LIBOR as a benchmark rate of interest was replaced by, in the case of U.S. dollar-denominated loans, a secured overnight financing rate subject to a spread adjustment, and, in the case of loans denominated in other currencies, other customary successor rates, subject in certain cases to a spread adjustment. On May 23, 2023, the Company entered into Amendment No. 13 to Credit Agreement, pursuant to which the spread adjustments with respect to the Original Revolving Credit Facility and the Original Term A Facility were amended. ​ On April 19, 2024, the Company entered into Amendment No. 14 to Syndicated Facility Agreement, pursuant to which the Company obtained a new $1,500,000,000 revolving credit facility (the “New Revolving Credit Facility”), a new $750,000,000 term loan A facility (the “New Term A Facility” and, together with the New Revolving Credit Facility, the “New Pro Rata Facilities”) and a new $700,000,000 term loan B facility (the “New Term B Facility” and, together with the New Pro Rata Facilities, the “New Credit Facilities”). The New Revolving Credit Facility and the New Term A Facility mature on April 19, 2029. The New Term B Facility matures on April 19, 2031. The New Term A Facility and the New Term B Facility were borrowed in full on April 19, 2024 in U.S. dollars. Loans under the New Revolving Credit Facility may be borrowed, and letters of credit thereunder may be issued, in U.S. dollars or in certain foreign currencies. The New Credit Facilities replace in full the Original Revolving Credit Facility, the Original Term A Facility and the Original Term B Facility, and borrowings under the New Credit Facilities were used to refinance in full the Original Credit Facilities and for general corporate purposes. The Credit Agreement permits the Company to designate certain of its subsidiaries as additional co-borrowers from time to time. Currently, there are no co-borrowers under the New Credit Facilities. ​ Borrowings under (a) the New Revolving Credit Facility (in U.S. dollars) and the New Term A Facility will bear interest at a rate per annum equal to, at the Company’s option, (i) a Term SOFR rate (with a 0% floor and SOFR adjustment of 0.10%) or (ii) a base rate (with a 0% floor), in each case, plus an applicable margin of 1.25% in the case of the Term SOFR rate and 0.25% in the case of the base rate, and (b) the New Revolving Credit Facility in currencies other U.S. dollars will bear interest at a rate per annum equal to the applicable reference rate for such currency (including any related adjustments), plus an applicable margin of 1.25%. The applicable margin is subject, in each case, to adjustment based on the Company’s consolidated leverage ratio from time to time. ​ Borrowings under the New Term B Facility will bear interest at a rate per annum equal to, at the Company’s option, (a) a Term SOFR rate (with a 0% floor and a SOFR adjustment of 0%) or (b) a base rate (with a 0% floor), in each case, plus an applicable margin of 1.875% in the case of the Term SOFR rate and 0.875% in the case of the base rate. ​ Certain of the Company’s material subsidiaries (the “Guarantors”) have guaranteed the Company’s obligations of the borrowers under the Credit Agreement, subject to certain exceptions. The borrowers’ obligations under the Credit Agreement are secured by a lien on substantially all of the Company’s assets and its Guarantors’ assets, subject to certain exceptions. ​ The Credit Agreement contains customary negative covenants that include, among other things, limitations on the ability of the Company and certain of its subsidiaries, subject to certain exceptions, to incur liens and debt, make investments, dispositions, and restricted payments, change the nature of their business, consummate mergers, consolidations and the sale of all or substantially all of their respective assets and transact with affiliates. The Company is also required to maintain a consolidated leverage ratio of less than or equal to 4.00 to 1.00 (subject to certain adjustments in connection with permitted acquisitions), tested on a quarterly basis (the “Financial Covenants”). The Financial Covenants do not apply to the New Term B Facility. As of March 31, 2024, the Company was in compliance with the covenants of the Credit Agreement. ​ The Credit Agreement contains customary affirmative covenants, including, among other things, compliance with applicable law, preservation of existence, maintenance of properties and of insurance, and keeping proper books and records. The Credit Agreement contains customary events of default, including, among other things, nonpayment of principal, interest or fees, cross-defaults to other debt, inaccuracies of representations and warranties, failure to perform covenants, events of bankruptcy and insolvency, change of control and unsatisfied judgments, subject in certain cases to notice and cure periods and other exceptions. ​ At March 31, 2024 and September 30, 2023, letters of credit totaled $4.4 million and $4.4 million, respectively, under the Company’s Original Revolving Credit Facility. As of March 31, 2024 and September 30, 2023, the Company had $1,145.6 million and $1,145.6 million, respectively, available under its Original Revolving Credit Facility ​ 2027 Senior Notes ​ On February 21, 2017, the Company completed a private placement offering of $1,000,000,000 aggregate principal amount of its unsecured 5.125% Senior Notes due 2027 (the “2027 Senior Notes”). On June 30, 2017, the Company completed an exchange offer to exchange the unregistered 2027 Senior Notes for registered notes, as well as related guarantees. ​ As of March 31, 2024, the estimated fair value of the 2027 Senior Notes was approximately $977.3 million. The fair value of the 2027 Senior Notes as of March 31, 2024 was derived by taking the mid-point of the trading prices from an observable market input (Level 2) in the secondary bond market and multiplying it by the outstanding balance of the 2027 Senior Notes. Interest is payable on the 2027 Senior Notes at a rate of 5.125% per annum. Interest on the 2027 Senior Notes is payable semi-annually on March 15 and September 15 of each year, commencing on September 15, 2017. The 2027 Senior Notes will mature on March 15, 2027. ​ At any time and from time to time prior to December 15, 2026, the Company may redeem all or part of the 2027 Senior Notes, at a redemption price equal to 100% of their principal amount, plus a “make whole” premium as of the redemption date, and accrued and unpaid interest to the redemption date. On or after December 15, 2026, the Company may redeem all or part of the 2027 Senior Notes at a redemption price equal to 100% of their principal amount, plus accrued and unpaid interest on the redemption date. ​ The indenture pursuant to which the 2027 Senior Notes were issued contains customary events of default, including, among other things, payment default, exchange default, failure to provide notices thereunder and provisions related to bankruptcy events. The indenture also contains customary negative covenants. ​ The Company was in compliance with the covenants relating to the 2027 Senior Notes as of March 31, 2024. ​ Other Debt and Other Items ​ Other debt consists primarily of obligations under capital leases and loans, and unsecured credit facilities. The Company’s unsecured credit facilities are primarily used for standby letters of credit issued in connection with general and professional liability insurance programs and for contract performance guarantees. At March 31, 2024 and September 30, 2023, these outstanding standby letters of credit totaled $895.3 million and $878.9 million, respectively. As of March 31, 2024, the Company had $418.9 million available under these unsecured credit facilities. ​ Effective Interest Rate ​ The Company’s average effective interest rate on its total debt, including the effects of the interest rate swap and interest rate cap agreements, during the six months ended March 31, 2024 and 2023 was 5.5% and 5.2%, respectively. ​ Interest expense in the consolidated statements of operations included amortization of deferred debt issuance costs for the three and six months ended March 31, 2024 of $1.2 million and $2.4 million, respectively, and for the three and six months ended March 31, 2023 of $1.2 million and $2.4 million, respectively.

Derivative Financial Instrument

Derivative Financial Instruments and Fair Value Measurements	6 Months Ended
	Mar. 31, 2024
Derivative Financial Instruments and Fair Value Measurements
Derivative Financial Instruments and Fair Value Measurements	8. Derivative Financial Instruments and Fair Value Measurements ​ The Company uses interest rate derivative contracts to hedge interest rate exposures on the Company’s variable rate debt. The Company enters into foreign currency derivative contracts with financial institutions to reduce the risk that its cash flows and earnings will be adversely affected by foreign currency exchange rate fluctuations. The Company’s hedging program is not designated for trading or speculative purposes. ​ The Company recognizes derivative instruments as either assets or liabilities on the accompanying consolidated balance sheets at fair value. The Company records changes in the fair value (i.e., gains or losses) of the derivatives that have been designated as accounting hedges in the accompanying consolidated statements of operations as cost of revenue, interest expense or to accumulated other comprehensive loss in the accompanying consolidated balance sheets. ​ Cash Flow Hedges ​ The Company uses interest rate swap and interest rate cap agreements designated as cash flow hedges to limit exposure to variable interest rates on portions of the Company’s debt. The Company initially reports any gain on the effective portion of a cash flow hedge as a component of accumulated other comprehensive loss. Depending on the type of cash flow hedge, the gain is subsequently reclassified against interest expense when the interest expense on the variable rate debt is recognized. If the hedged transaction becomes probable of not occurring, any gain or loss related to interest rate swap or interest rate cap agreements would be recognized in other income. ​ During the third quarter of fiscal 2023, the hedged debt index was changed from LIBOR to SOFR. The notional principal, fixed rates and related effective and expiration dates of the Company’s outstanding interest rate swap agreements were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 Notional Amount ​ Notional Amount ​ Fixed ​ Effective ​ Expiration Currency (in millions) Rate Date Date USD ​ 400.0 ​ 1.283% ​ February 2023 ​ March 2028 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 Notional Amount ​ Notional Amount ​ Fixed ​ Effective ​ Expiration Currency (in millions) Rate Date Date USD ​ 400.0 1.283% ​ February 2023 ​ March 2028 ​ In the fourth quarter of fiscal 2021, the Company entered into new interest rate swap agreements with a notional value of $400.0 million to manage the interest rate exposure of its variable rate loans. The new swaps became effective February 2023 and terminate in March 2028. By entering into the swap agreements, the Company converted a portion of the SOFR rate-based liability into a fixed rate liability. The Company will pay a fixed rate of 1.283% and receive payment at the prevailing one-month SOFR. In the third quarter of fiscal 2022, the Company purchased interest rate cap agreements with a notional value of $300.0 million to manage interest rate exposure of its variable rate loans. The caps became effective on June 30, 2022 and terminate in March 2028. The caps reduce the Company’s exposure to one-month SOFR. In the event one-month SOFR exceeds 3.465%, the Company will receive the spread between prevailing one-month SOFR and 3.465%. ​ Other Foreign Currency Forward Contracts ​ The Company uses foreign currency forward contracts which are not designated as accounting hedges to hedge intercompany transactions and other monetary assets or liabilities denominated in currencies other than the functional currency of a subsidiary. Gains and losses on these contracts were not material for the six months ended March 31, 2024 and 2023. ​ Fair Value Measurements ​ The Company’s non-pension financial assets and liabilities recorded at fair value relate to the interest rate swap and interest rate cap agreements included in other current assets, other non-current assets, and other non-current liabilities on March 31, 2024 were $15.2 million, $27.1 million and $0.6 million, respectively. The fair values of the interest rate swap and interest rate cap agreements included in other current assets and other non-current assets on September 30, 2023 were $17.2 million and $37.5 million, respectively. The fair values of the interest rate swap and interest rate cap agreements were derived by taking the net present value of the expected cash flows using observable market inputs (Level 2) such as SOFR rate curves, futures, volatilities and basis spreads (when applicable). ​ See Note 14 for accumulated balances and reporting period activities of derivatives related to reclassifications out of accumulated other comprehensive loss for the six months ended March 31, 2024 and 2023. Additionally, there were no material losses recognized in income due to amounts excluded from effectiveness testing from the Company’s interest rate swap and interest rate cap agreements.

Share-Based Payments

Share-Based Payments	6 Months Ended
	Mar. 31, 2024
Share-based Payments
Share-based Payments	9. Share-based Payments ​ The Company grants stock units to employees under its Performance Earnings Program (PEP), whereby units are earned and issued dependent upon meeting established cumulative performance objectives and vest over a three-year service period. Additionally, the Company issues restricted stock units to employees which are earned based on service conditions. The grant date fair value of PEP awards and restricted stock unit awards is primarily based on that day’s closing market price of the Company’s common stock. Restricted stock units and PEP units activity for the six months ended March 31 was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 ​ ​ Weighted ​ Weighted ​ Weighted ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Average ​ ​ Restricted ​ Grant-Date ​ ​ ​ Grant-Date ​ Restricted ​ Grant-Date ​ ​ ​ Grant-Date ​ ​ Stock Units ​ Fair Value ​ PEP Units ​ Fair Value ​ Stock Units ​ Fair Value ​ PEP Units ​ Fair Value ​ ​ (in millions) ​ ​ ​ ​ (in millions) ​ ​ ​ ​ (in millions) ​ ​ ​ ​ (in millions) ​ ​ ​ Outstanding at September 30, ​ 0.8 ​ $ 68.34 ​ 0.7 ​ $ 75.54 ​ 1.0 ​ $ 53.05 ​ 0.7 ​ $ 60.60 Granted ​ 0.3 ​ $ 92.32 ​ 0.2 ​ $ 104.82 ​ 0.3 ​ $ 83.64 ​ 0.2 ​ $ 94.65 PEP units earned — ​ $ — ​ 0.2 ​ $ 52.49 ​ — ​ $ — ​ 0.2 ​ $ 43.19 Vested (0.3) ​ $ 49.99 ​ (0.4) ​ $ 52.49 ​ (0.4) ​ $ 44.95 ​ (0.4) ​ $ 43.19 Outstanding at March 31, 0.8 ​ $ 83.90 ​ 0.7 ​ $ 95.37 ​ 0.9 ​ $ 65.75 ​ 0.7 ​ $ 75.53 ​ Total compensation expense related to these share-based payments including stock options was $30.6 million and $24.6 million during the six months ended March 31, 2024 and 2023, respectively. Unrecognized compensation expense related to total share-based payments outstanding as of March 31, 2024 and September 30, 2023 was $78.7 million and $48.3 million, respectively, to be recognized on a straight-line basis over the awards’ respective vesting periods which are generally three years.

Income Taxes

Income Taxes	6 Months Ended
	Mar. 31, 2024
Income Taxes
Income Taxes	10. Income Taxes ​ The Company’s effective tax rate was 23.4% and 23.1% for the six months ended March 31, 2024 and 2023, respectively. The most significant items contributing to the difference between the statutory U.S. federal corporate tax rate of 21.0% and the Company’s effective tax rate for the six-month period ended March 31, 2024 were a tax benefit of $29.4 million related to income tax credits and incentives, tax expense of $26.2 million related to foreign residual income, tax expense of $12.3 million related to state income taxes, a tax benefit of $6.9 million related to an audit settlement, and tax expense of $6.6 million related to changes in valuation allowances. All these items, except for the audit settlement, are expected to have a continuing impact on the effective tax rate for the remainder of the fiscal year. ​ The most significant items contributing to the difference between the statutory U.S. federal corporate tax rate of 21.0% and the Company’s effective tax rate for the six-month period ended March 31, 2023 were a tax benefit of $23.6 million related to income tax credits and incentives, tax expense of $19.1 million related to foreign residual income, and tax expense of $9.0 million related to state income taxes. ​ During the first quarter of fiscal 2024, the Company settled its tax audit in Hong Kong for fiscal year 2011 through fiscal year 2021 and recorded a tax benefit of $6.9 million due primarily to changes in uncertain tax positions. ​ The Company is utilizing the annual effective tax rate method under ASC 740 to compute its interim tax provision. The Company’s effective tax rate fluctuates from quarter to quarter due to various factors including the change in the mix of global income and expenses, outcomes of administrative audits, changes in the assessment of valuation allowances due to management’s consideration of new positive or negative evidence during the quarter, and changes in enacted tax laws. The U.S.and many international legislative and regulatory bodies have proposed legislation that could significantly impact how our business activities are taxed. These proposed changes could have a material impact on the Company’s income tax expense and deferred tax balances. ​ The Company is currently under tax audit in several jurisdictions including the U.S. where its federal income tax returns for fiscal 2017 through 2020 are being examined by the IRS. Disputes can arise with tax authorities involving issues related to the timing of deductions, the calculation and use of credits, and the taxation of income in various tax jurisdictions because of differing interpretations or application of tax laws, regulations, and relevant facts. The IRS is currently auditing certain tax credits and the methodology for calculating the credits. While the Company has reserves for uncertain tax positions and has historically been able to sustain the credits in previous audit cycles without adjustment, the Company believes it’s reasonably possible there could be an adjustment to the liability for uncertain tax positions within the next twelve months related to this issue. However, given the early stages of the audit of these credits, the Company is not able to reasonably estimate the range of potential outcomes. ​ Generally, the Company does not provide for U.S. taxes or foreign withholding taxes on gross book-tax differences in its non-U.S. subsidiaries because such basis differences of approximately $1.3 billion are able to and intended to be reinvested indefinitely. If these basis differences were distributed, foreign tax credits could become available under current law to partially or fully reduce the resulting U.S. income tax liability. There may also be additional U.S. or foreign income tax liability upon repatriation, although the calculation of such additional taxes is not practicable. ​

Earnings Per Share

Earnings Per Share	6 Months Ended
	Mar. 31, 2024
Earnings Per Share
Earnings Per Share	11. Earnings Per Share ​ Basic earnings per share (EPS) excludes dilution and is computed by dividing net income attributable to AECOM by the weighted average number of common shares outstanding for the period. Diluted EPS is computed by dividing net income attributable to AECOM by the weighted average number of common shares outstanding and potential common shares for the period. The Company includes as potential common shares the weighted average dilutive effects of equity awards using the treasury stock method. For the three and six months ended March 31, 2024 and 2023, equity awards excluded from the calculation of potential common shares were not significant. ​ The following table sets forth a reconciliation of the denominators for basic and diluted earnings per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ March 31, ​ March 31, March 31, March 31, ​ 2024 2023 2024 2023 ​ ​ (in millions) Denominator for basic earnings per share ​ 136.0 ​ 138.9 ​ 136.0 ​ 138.8 Potential common shares ​ 0.7 ​ 1.4 ​ 0.9 ​ 1.7 Denominator for diluted earnings per share ​ 136.7 ​ 140.3 ​ 136.9 ​ 140.5 ​

Leases

Leases	6 Months Ended
	Mar. 31, 2024
Leases
Leases	12. Leases ​ The Company and its subsidiaries are lessees in non-cancelable leasing agreements for office buildings and equipment. Substantially all of the Company’s office building leases are operating leases, and its equipment leases are both operating and finance leases. The Company groups lease and non-lease components for its equipment leases into a single lease component but separates lease and non-lease components for its office building leases. ​ The Company recognizes a right-of-use asset and lease liability for its operating leases at the commencement date equal to the present value of the contractual minimum lease payments over the lease term. The present value is calculated using the rate implicit in the lease, if known, or the Company’s incremental secured borrowing rate. The discount rate used for operating leases is primarily determined based on an analysis of the Company’s incremental secured borrowing rate, while the discount rate used for finance leases is primarily determined by the rate specified in the lease. ​ The related lease payments are expensed on a straight-line basis over the lease term, including, as applicable, any free-rent period during which the Company has the right to use the asset. For leases with renewal options where the renewal is reasonably assured, the lease term, including the renewal period, is used to determine the appropriate lease classification and to compute periodic rental expense. Leases with initial terms shorter than 12 months are not recognized on the balance sheet, and lease expense is recognized on a straight-line basis. ​ The components of lease expenses are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ March 31, 2024 March 31, 2023 March 31, 2024 March 31, 2023 ​ ​ (in millions) Operating lease cost ​ $ 37.7 ​ $ 41.6 ​ $ 75.1 ​ $ 83.1 Finance lease cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ 7.3 ​ ​ 5.7 ​ ​ 14.1 ​ ​ 10.8 Interest on lease liabilities ​ 0.7 ​ ​ 0.6 ​ ​ 1.5 ​ ​ 1.2 Variable lease cost ​ 8.6 ​ ​ 8.6 ​ ​ 17.5 ​ ​ 16.5 Total lease cost ​ $ 54.3 ​ $ 56.5 ​ $ 108.2 ​ $ 111.6 ​ Additional balance sheet information related to leases is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of (in millions except as noted) Balance Sheet Classification March 31, 2024 September 30, 2023 Assets: ​ ​ ​ ​ Operating lease assets Operating lease right-of-use assets ​ $ 422.9 ​ $ 447.0 Finance lease assets Property and equipment – net ​ ​ 69.1 ​ ​ 64.8 Total lease assets ​ $ 492.0 ​ $ 511.8 ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ Current: ​ ​ ​ ​ ​ ​ Operating lease liabilities Accrued expenses and other current liabilities ​ $ 142.0 ​ $ 139.8 Finance lease liabilities Current portion of long-term debt ​ ​ 27.3 ​ ​ 25.0 Total current lease liabilities ​ ​ 169.3 ​ ​ 164.8 Non-current: ​ ​ ​ ​ ​ ​ Operating lease liabilities Operating lease liabilities, noncurrent ​ ​ 507.5 ​ ​ 548.9 Finance lease liabilities Long-term debt ​ ​ 41.3 ​ ​ 39.8 Total non-current lease liabilities ​ $ 548.8 ​ $ 588.7 ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ March 31, 2024 September 30, 2023 ​ Weighted average remaining lease term (in years): ​ ​ ​ Operating leases 6.2 ​ 6.4 ​ Finance leases 2.8 ​ 2.9 ​ Weighted average discount rates: ​ ​ ​ ​ Operating leases 5.0 % 4.3 % Finance leases 4.3 % 4.1 % ​ Additional cash flow information related to leases is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ March 31, ​ March 31, ​ 2024 2023 ​ ​ (in millions) Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 92.7 ​ $ 94.8 Operating cash flows from finance leases ​ ​ 1.6 ​ ​ 1.2 Financing cash flows from finance leases ​ ​ 15.1 ​ ​ 11.3 Right-of-use assets obtained in exchange for new operating leases ​ ​ 38.0 ​ ​ 66.4 Right-of-use assets obtained in exchange for new finance leases ​ ​ 17.9 ​ ​ 19.6 ​ ​ Total remaining lease payments under both the Company’s operating and finance leases are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Finance Leases Fiscal Year ​ (in millions) 2024 (six months remaining) ​ $ 89.3 ​ $ 15.5 2025 ​ 152.4 ​ ​ 26.6 2026 ​ 121.3 ​ ​ 19.4 2027 ​ 92.2 ​ ​ 10.4 2028 ​ ​ 79.9 ​ ​ 1.3 Thereafter ​ 223.5 ​ ​ — Total lease payments ​ $ 758.6 ​ $ 73.2 Less: Amounts representing interest ​ $ (109.1) ​ $ (4.6) Total lease liabilities ​ $ 649.5 ​ $ 68.6 ​

Other Financial Information

Other Financial Information	6 Months Ended
	Mar. 31, 2024
Other Financial Information
Other Financial Information	13. Other Financial Information ​ Accrued expenses and other current liabilities consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, September 30, ​ ​ 2024 ​ 2023 ​ ​ (in millions) Accrued salaries and benefits ​ $ 569.6 ​ $ 599.8 Accrued contract costs ​ 1,416.7 ​ ​ 1,340.4 Other accrued expenses ​ 398.9 ​ ​ 347.3 Total ​ $ 2,385.2 ​ $ 2,287.5 ​ Accrued contract costs above include balances related to professional liability accruals of $793.8 million and $809.6 million as of March 31, 2024 and September 30, 2023, respectively. The remaining accrued contract costs primarily relate to costs for services provided by subcontractors and other non-employees. Liabilities recorded related to accrued contract losses were not material as of March 31, 2024 and September 30, 2023. The Company did not have material revisions to estimates for contracts where revenue is recognized using the input method during the six months ended March 31, 2024 and 2023. During the first half of fiscal 2024, the Company incurred restructuring expenses of $51.6 million, including personnel and other costs of $38.6 million and real estate costs of $13.0 million, of which $7.3 million was accrued and unpaid at March 31, 2024. During the first half of fiscal 2023, the Company incurred restructuring expenses of $41.4 million, including personnel and other costs of $39.0 million and real estate costs of $2.4 million, of which $30.7 million was accrued and unpaid at March 31, 2023. On March 21, 2024, the Company’s Board of Directors declared a quarterly cash dividend of $0.22 per share, which is payable on May 10, 2024 to stockholders of record as of April 24, 2024. As of March 31, 2024, accrued and unpaid dividends totaled $32.1 million and were classified within other accrued expenses on the consolidated balance sheet.

Reclassifications out of Accumu

Reclassifications out of Accumulated Other Comprehensive Loss	6 Months Ended
	Mar. 31, 2024
Reclassifications out of Accumulated Other Comprehensive Loss
Reclassifications out of Accumulated Other Comprehensive Loss	14. Reclassifications out of Accumulated Other Comprehensive Loss ​ The accumulated balances and reporting period activities for the three and six months ended March 31, 2024 and 2023 related to reclassifications out of accumulated other comprehensive loss are summarized as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ Related Translation Derivative Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at December 31, 2023 ​ $ (235.0) ​ $ (679.7) ​ $ 24.9 ​ $ (889.8) Other comprehensive income (loss) before reclassification ​ 1.9 ​ ​ (27.0) ​ ​ 8.3 ​ ​ (16.8) Amounts reclassified from accumulated other comprehensive loss ​ 0.1 ​ ​ — ​ ​ (3.5) ​ ​ (3.4) Balances at March 31, 2024 ​ $ (233.0) ​ $ (706.7) ​ $ 29.7 ​ $ (910.0) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at December 31, 2022 ​ $ (232.1) ​ $ (721.4) ​ $ 35.1 ​ $ (918.4) Other comprehensive (loss) income before reclassification ​ ​ (4.2) ​ ​ 8.5 ​ ​ (5.6) ​ ​ (1.3) Amounts reclassified from accumulated other comprehensive income (loss) ​ 0.5 ​ ​ — ​ ​ (1.9) ​ ​ (1.4) Balances at March 31, 2023 ​ $ (235.8) ​ $ (712.9) ​ $ 27.6 ​ $ (921.1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at September 30, 2023 ​ $ (226.0) ​ $ (739.7) ​ $ 39.1 ​ $ (926.6) Other comprehensive (loss) income before reclassification ​ ​ (7.2) ​ ​ 33.0 ​ ​ (2.3) ​ ​ 23.5 Amounts reclassified from accumulated other comprehensive loss ​ ​ 0.2 ​ ​ — ​ ​ (7.1) ​ ​ (6.9) Balances at March 31, 2024 ​ $ (233.0) ​ $ (706.7) ​ $ 29.7 ​ $ (910.0) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at September 30, 2022 ​ $ (217.3) ​ $ (799.3) ​ $ 36.9 ​ $ (979.7) Other comprehensive (loss) income before reclassification ​ (19.6) ​ ​ 86.4 ​ ​ (7.4) ​ ​ 59.4 Amounts reclassified from accumulated other comprehensive income (loss) ​ ​ 1.1 ​ ​ — ​ ​ (1.9) ​ ​ (0.8) Balances at March 31, 2023 ​ $ (235.8) ​ $ (712.9) ​ $ 27.6 ​ $ (921.1) ​

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Mar. 31, 2024
Commitments and Contingencies
Commitments and Contingencies	15. Commitments and Contingencies ​ The Company records amounts representing its probable estimated liabilities relating to claims, guarantees, litigation, audits and investigations. The Company relies in part on qualified actuaries to assist it in determining the level of reserves to establish for insurance-related claims that are known and have been asserted against it, and for insurance-related claims that are believed to have been incurred based on actuarial analysis, but have not yet been reported to the Company’s claims administrators as of the respective balance sheet dates. The Company includes any adjustments to such insurance reserves in its consolidated results of operations. The Company’s reasonably possible loss disclosures are presented on a gross basis prior to the consideration of insurance recoveries. The Company does not record gain contingencies until they are realized. In the ordinary course of business, the Company may not be aware that it or its affiliates are under investigation and may not be aware of whether or not a known investigation has been concluded. ​ In the ordinary course of business, the Company may enter into various arrangements providing financial or performance assurance to clients, lenders, or partners. Such arrangements include standby letters of credit, surety bonds, and corporate guarantees to support the creditworthiness or the project execution commitments of its affiliates, partnerships and joint ventures. The Company’s unsecured credit arrangements are used for standby letters of credit issued in connection with general and professional liability insurance programs and for contract performance guarantees. At March 31, 2024 and September 30, 2023, these outstanding standby letters of credit totaled $895.3 million and $878.9 million, respectively. As of March 31, 2024, the Company had $418.9 million available under these unsecured credit facilities. Performance arrangements typically have various expiration dates ranging from the completion of the project contract and extending beyond contract completion in some circumstances such as for warranties. The Company may also guarantee that a project, when complete, will achieve specified performance standards. If the project subsequently fails to meet guaranteed performance standards, the Company may incur additional costs, pay liquidated damages or be held responsible for the costs incurred by the client to achieve the required performance standards. The potential payment amount of an outstanding performance arrangement is typically the remaining cost of work to be performed by or on behalf of third parties. Generally, under joint venture arrangements, if a partner is financially unable to complete its share of the contract, the other partner(s) may be required to complete those activities. ​ At March 31, 2024, the Company was contingently liable in the amount of approximately $899.7 million in issued standby letters of credit and $4.7 billion in issued surety bonds primarily to support project execution. ​ In the ordinary course of business, the Company enters into various agreements providing financial or performance assurances to clients on behalf of certain unconsolidated partnerships, joint ventures and other jointly executed contracts. These agreements are entered into primarily to support the project execution commitments of these entities. ​ The Company’s investment adviser jointly manages and sponsors the AECOM-Canyon Equity Fund, L.P. (the “Fund”), in which the Company indirectly holds an equity interest and has an ongoing capital commitment to fund investments. At March 31, 2024, the Company has capital commitments of $7.1 million to the Fund over the next 5 years. ​ In addition, in connection with the investment activities of AECOM Capital, the Company provides guarantees of certain contractual obligations, including guarantees for completion of projects, repayment of debt, environmental indemnity obligations and other lender required guarantees. ​ In February 2024, the Company was informed of a potential liability as one of the indemnitors on a divested business’ surety bonds. The Company does not have sufficient information to determine the range of potential impacts, however, it is reasonably possible that the Company may incur additional costs related to these bonds. ​ Department of Energy Deactivation, Demolition, and Removal Project ​ A former affiliate of the Company, Amentum Environment & Energy, Inc., f/k/a AECOM Energy and Construction, Inc. (“Former Affiliate”), executed a cost-reimbursable task order with the Department of Energy (DOE) in 2007 to provide deactivation, demolition and removal services at a New York State project site that, during 2010, experienced contamination and performance issues. In February 2011, the Former Affiliate and the DOE executed a Task Order Modification that changed some cost-reimbursable contract provisions to at-risk. The Task Order Modification, including subsequent amendments, required the DOE to pay all project costs up to $106 million, required the Former Affiliate and the DOE to equally share in all project costs incurred from $106 million to $146 million, and required the Former Affiliate to pay all project costs exceeding $146 million. ​ Due to unanticipated requirements and permitting delays by federal and state agencies, as well as delays and related ground stabilization activities caused by Hurricane Irene in 2011, the Former Affiliate was required to perform work outside the scope of the Task Order Modification. In December 2014, the Former Affiliate submitted an initial set of claims against the DOE pursuant to the Contracts Disputes Acts seeking recovery of $103 million, including additional fees on changed work scope (the “2014 Claims”). On December 6, 2019, the Former Affiliate submitted a second set of claims against the DOE seeking recovery of an additional $60.4 million, including additional project costs and delays outside the scope of the contract as a result of differing site and ground conditions (the “2019 Claims”). The Former Affiliate also submitted three alternative breach of contract claims to the 2014 and 2019 Claims that may entitle the Former Affiliate to recovery of $148.5 million to $329.4 million. On December 30, 2019, the DOE denied the Former Affiliate’s 2014 Claims. On September 25, 2020, the DOE denied the Former Affiliate’s 2019 Claims. The Company filed an appeal of these decisions on December 20, 2020 in the Court of Federal Claims. Deconstruction, decommissioning and site restoration activities are complete. ​ On January 31, 2020, the Company completed the sale of its Management Services business, including the Former Affiliate who worked on the DOE project, to Maverick Purchaser Sub LLC (MS Purchaser), an affiliate of American Securities LLC and Lindsay Goldberg LLC. The Company and the MS Purchaser agreed that all future DOE project claim recoveries and costs will be split 10% to the MS Purchaser and 90% to the Company with the Company retaining control of all future strategic legal decisions. ​ The Company intends to vigorously pursue all claimed amounts but can provide no certainty that the Company will recover 2014 Claims and 2019 Claims submitted against the DOE, or any additional incurred claims or costs, which could have a material adverse effect on the Company’s results of operations. Refinery Turnaround Project ​ A Former Affiliate of the Company entered into an agreement to perform turnaround maintenance services during a planned shutdown at a refinery in Montana in December 2017. The turnaround project was completed in February 2019. Due to circumstances outside of the Company’s Former Affiliate’s control, including client directed changes and delays and the refinery’s condition, the Company’s Former Affiliate performed additional work outside of the original contract of over $90 million and is entitled to payment from the refinery owner of approximately $144 million. In March 2019, the refinery owner sent a letter to the Company’s Former Affiliate alleging it incurred approximately $79 million in damages due to the Company’s Former Affiliate’s project performance. In April 2019, the Company’s Former Affiliate filed and perfected a $132 million construction lien against the refinery for unpaid labor and materials costs. In August 2019, following a subcontractor complaint filed in the Thirteenth Judicial District Court of Montana asserting claims against the refinery owner and the Company’s Former Affiliate, the refinery owner crossclaimed against the Company’s Former Affiliate and the subcontractor. In October 2019, following the subcontractor’s dismissal of its claims, the Company’s Former Affiliate removed the matter to federal court and cross claimed against the refinery owner. In December 2019, the refinery owner claimed $93.0 million in damages and offsets against the Company’s Former Affiliate. ​ On January 31, 2020, the Company completed the sale of its Management Services business, including the Former Affiliate, to the MS Purchaser; however, the Refinery Turnaround Project, including related claims and liabilities, has been retained by the Company. Trial is expected to begin in the second quarter of fiscal year 2025. The Company intends to vigorously prosecute and defend this matter; however, the Company cannot provide assurance that the Company will be successful in these efforts. The resolution of this matter and any potential range of loss cannot be reasonably determined or estimated at this time, primarily because the matter raises complex legal issues that the Company is continuing to assess.

Reportable Segments

Reportable Segments	6 Months Ended
	Mar. 31, 2024
Reportable Segments
Reportable Segments	16. Reportable Segments ​ The Company manages its operations under three reportable segments according to their geographic regions and business activities. The Americas segment provides planning, consulting, architectural and engineering design services, and construction management services to public and private clients in the United States, Canada, and Latin America, while the International segment provides similar professional services to public and private clients in Europe, the Middle East, India, Africa, and the Asia-Australia-Pacific regions. The Company’s AECOM Capital (ACAP) segment primarily invests in and develops real estate projects. ​ Although the services provided are similar, these reportable segments are organized by the differing specialized needs of the respective clients, and how the Company manages its business. The Company has aggregated operating segments into its Americas and International reportable segments based on their similar characteristics, including similar long term financial performance, the nature of services provided, internal processes for delivering those services, and types of customers. ​ The following tables set forth summarized financial information concerning the Company’s reportable segments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ AECOM ​ ​ ​ ​ ​ ​ ​ Reportable Segments: Americas International Capital Corporate Total ​ ​ ​ ( $ in millions) Three Months Ended March 31, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 3,038.6 ​ $ 904.8 ​ $ 0.5 ​ $ — ​ $ 3,943.9 ​ Gross profit ​ ​ 184.4 ​ ​ 76.2 ​ ​ 0.5 ​ ​ — ​ ​ 261.1 ​ Equity in earnings of joint ventures ​ ​ 4.8 ​ ​ 5.0 ​ ​ 9.7 ​ ​ — ​ ​ 19.5 ​ General and administrative expenses ​ ​ — ​ ​ — ​ ​ (9.7) ​ ​ (35.0) ​ ​ (44.7) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (35.4) ​ ​ (35.4) ​ Operating income ​ ​ 189.2 ​ ​ 81.2 ​ ​ 0.5 ​ ​ (70.4) ​ ​ 200.5 ​ Gross profit as a % of revenue ​ 6.1 % ​ 8.4 % ​ ​ ​ ​ ​ ​ ​ 6.6 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 2,630.2 ​ $ 859.8 ​ $ 0.1 ​ $ — ​ $ 3,490.1 ​ Gross profit ​ ​ 173.3 ​ ​ 54.7 ​ ​ 0.1 ​ ​ — ​ ​ 228.1 ​ Equity in earnings of joint ventures ​ ​ 4.9 ​ ​ 5.4 ​ ​ (2.8) ​ ​ — ​ ​ 7.5 ​ General and administrative expenses ​ ​ — ​ ​ — ​ ​ (2.9) ​ ​ (31.3) ​ ​ (34.2) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (3.9) ​ ​ (3.9) ​ Operating income (loss) ​ ​ 178.2 ​ ​ 60.1 ​ ​ (5.6) ​ ​ (35.2) ​ ​ 197.5 ​ Gross profit as a % of revenue ​ 6.6 % ​ 6.4 % ​ ​ ​ ​ ​ ​ ​ 6.5 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended March 31, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 6,077.3 ​ $ 1,765.8 ​ $ 0.7 ​ $ — ​ $ 7,843.8 ​ Gross profit ​ ​ 355.4 ​ ​ 149.0 ​ ​ 0.7 ​ ​ — ​ ​ 505.1 ​ Equity in earnings of joint ventures ​ ​ 8.4 ​ ​ 9.3 ​ ​ (27.2) ​ ​ — ​ ​ (9.5) ​ General and administrative expenses ​ ​ — ​ ​ — ​ ​ (12.1) ​ ​ (68.3) ​ ​ (80.4) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (51.6) ​ ​ (51.6) ​ Operating income (loss) ​ ​ 363.8 ​ ​ 158.3 ​ ​ (38.6) ​ ​ (119.9) ​ ​ 363.6 ​ Gross profit as a % of revenue ​ ​ 5.8 % ​ 8.4 % ​ ​ ​ ​ ​ ​ ​ 6.4 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 5,209.5 ​ $ 1,662.6 ​ $ 0.4 ​ $ — ​ $ 6,872.5 ​ Gross profit ​ ​ 336.2 ​ ​ 106.5 ​ ​ 0.4 ​ ​ — ​ ​ 443.1 ​ Equity in earnings of joint ventures ​ ​ 5.8 ​ ​ 8.7 ​ ​ 2.8 ​ ​ — ​ ​ 17.3 ​ General and administrative expenses ​ ​ — ​ ​ — ​ ​ (5.6) ​ ​ (64.2) ​ ​ (69.8) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (41.4) ​ ​ (41.4) ​ Operating income (loss) ​ ​ 342.0 ​ ​ 115.2 ​ ​ (2.4) ​ ​ (105.6) ​ ​ 349.2 ​ Gross profit as a % of revenue ​ 6.5 % ​ 6.4 % ​ ​ ​ ​ ​ ​ ​ 6.4 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reportable Segments: ​ ​ ​ ​ ​ Total assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 ​ $ 7,754.4 ​ $ 2,671.4 ​ $ 53.2 ​ $ 873.3 ​ ​ September 30, 2023 ​ $ 7,433.1 ​ $ 2,536.2 ​ $ 64.5 ​ $ 1,104.4 ​ ​ ​

Discontinued Operations, Good_2

Discontinued Operations, Goodwill, and Intangible Assets (Tables)	6 Months Ended
	Mar. 31, 2024
Discontinued Operations, Goodwill, and Intangible Assets
Schedule of balance sheet and income statement information of discontinued operations and significant components included in consolidated statement of cash flows	The following table represents summarized balance sheet information of assets and liabilities held for sale (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ September 30, ​ 2024 2023 ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 3.3 ​ $ 1.9 Receivables and contract assets ​ 101.3 ​ ​ 93.3 Other ​ 0.5 ​ ​ — Current assets held for sale ​ $ 105.1 ​ $ 95.2 ​ ​ ​ ​ ​ ​ ​ Property and equipment, net ​ $ 15.8 ​ $ 14.2 Write-down of assets to fair value less cost to sell ​ ​ (15.8) ​ ​ (14.2) Non-current assets held for sale ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ Accounts payable and accrued expenses ​ $ 51.1 ​ ​ 45.6 Current liabilities held for sale ​ $ 51.1 ​ $ 45.6 ​ ​ ​ ​ ​ ​ ​ Long-term liabilities held for sale ​ $ 0.8 ​ $ 0.8 ​ The following table represents summarized income statement information of discontinued operations (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended Six months ended ​ ​ March 31, ​ March 31, March 31, ​ March 31, ​ 2024 2023 2024 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 46.5 ​ $ 58.8 ​ $ 101.1 ​ $ 100.5 Cost of revenue ​ 45.0 ​ ​ 62.1 ​ ​ 97.7 ​ ​ 102.4 Gross profit (loss) ​ 1.5 ​ ​ (3.3) ​ ​ 3.4 ​ ​ (1.9) Equity in earnings of joint ventures ​ (3.4) ​ ​ — ​ ​ (3.4) ​ ​ (1.7) Loss on disposal activities ​ ​ (109.6) ​ ​ (40.2) ​ ​ (113.1) ​ ​ (40.2) Transaction costs ​ ​ (0.2) ​ ​ — ​ ​ (0.2) ​ ​ (0.2) Loss from operations ​ (111.7) ​ ​ (43.5) ​ ​ (113.3) ​ ​ (44.0) Other loss ​ (0.5) ​ ​ — ​ ​ (1.1) ​ ​ — Loss before taxes ​ (112.2) ​ ​ (43.5) ​ ​ (114.4) ​ ​ (44.0) Income tax benefit ​ (2.8) ​ ​ (1.7) ​ ​ (3.7) ​ ​ (1.8) Net loss from discontinuing operations ​ $ (109.4) ​ $ (41.8) ​ $ (110.7) ​ $ (42.2) ​ The significant components included in our Consolidated Statement of Cash Flows for the discontinued operations are as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended Six months ended ​ ​ March 31, March 31, ​ March 31, March 31, ​ 2024 ​ 2023 2024 ​ 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Payments for capital expenditures ​ $ 2.1 ​ $ 0.5 ​ $ 2.1 ​ $ 4.5 ​
Schedule of changes in the carrying value of goodwill by reportable segment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ Exchange ​ ​ ​ ​ March 31, ​ 2023 Impact Acquired 2024 ​ ​ (in millions) Americas ​ $ 2,614.0 ​ $ 0.5 ​ $ 12.2 ​ $ 2,626.7 International ​ 804.9 ​ ​ 15.4 ​ ​ — ​ ​ 820.3 Total ​ $ 3,418.9 ​ $ 15.9 ​ $ 12.2 ​ $ 3,447.0
Schedule of gross amounts and accumulated amortization of finite intangible assets included in intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 ​ September 30, 2023 ​ ​ ​ ​ Gross ​ Accumulated ​ Intangible ​ Gross ​ Accumulated ​ Intangible ​ Amortization ​ Amount Amortization Assets, Net Amount Amortization Assets, Net Period ​ ​ (in millions) ​ (years) Backlog and Customer relationships ​ $ 671.5 ​ $ (655.4) ​ $ 16.1 ​ $ 663.8 ​ $ (646.0) ​ $ 17.8 ​ 1 - 11
Schedule of estimated future amortization expense of intangible assets	​ ​ ​ ​ ​ Fiscal Year (in millions) 2024 (six months remaining) ​ $ 9.2 2025 ​ 2.1 2026 ​ 1.5 2027 ​ 1.5 2028 ​ ​ 1.5 Thereafter ​ 0.3 Total ​ $ 16.1 ​

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Mar. 31, 2024
Revenue Recognition.
Schedule of revenues disaggregated by revenue sources	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ March 31, ​ March 31, ​ March 31, ​ March 31, ​ 2024 2023 2024 2023 ​ (in millions) Cost reimbursable ​ $ 1,605.1 ​ $ 1,511.3 ​ $ 3,222.3 ​ $ 3,026.2 Guaranteed maximum price ​ ​ 1,420.7 ​ ​ 1,151.0 ​ ​ 2,835.6 ​ ​ 2,239.2 Fixed-price ​ ​ 918.1 ​ ​ 827.8 ​ ​ 1,785.9 ​ ​ 1,607.1 Total revenue ​ $ 3,943.9 ​ $ 3,490.1 ​ $ 7,843.8 ​ $ 6,872.5 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ March 31, ​ March 31, ​ March 31, ​ March 31, ​ 2024 2023 2024 2023 ​ (in millions) Americas ​ $ 3,039.1 ​ $ 2,630.3 ​ $ 6,077.9 ​ $ 5,209.9 Europe, Middle East, India, Africa ​ ​ 619.8 ​ ​ 494.1 ​ ​ 1,115.2 ​ ​ 942.1 Asia-Australia-Pacific ​ ​ 285.0 ​ ​ 365.7 ​ ​ 650.7 ​ ​ 720.5 Total revenue ​ $ 3,943.9 ​ $ 3,490.1 ​ $ 7,843.8 ​ $ 6,872.5 ​
Schedule of net accounts receivable	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ September 30, ​ ​ 2024 2023 ​ ​ (in millions) Billed ​ $ 2,125.4 ​ $ 2,122.2 Contract retentions ​ 602.8 ​ ​ 516.5 Total accounts receivable—gross ​ 2,728.2 ​ ​ 2,638.7 Allowance for doubtful accounts and credit losses ​ (81.5) ​ ​ (94.2) Total accounts receivable—net ​ $ 2,646.7 ​ $ 2,544.5

Joint Ventures and Variable I_2

Joint Ventures and Variable Interest Entities (Tables)	6 Months Ended
	Mar. 31, 2024
Joint Ventures and Variable Interest Entities
Schedule of financial information of the consolidated joint ventures	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ ​ ​ ​ 2024 ​ September 30, ​ ​ (unaudited) ​ 2023 ​ ​ (in millions) Current assets ​ $ 970.0 ​ $ 806.3 Non-current assets ​ 84.5 ​ ​ 75.9 Total assets ​ $ 1,054.5 ​ $ 882.2 ​ ​ ​ ​ ​ ​ ​ Current liabilities ​ $ 878.4 ​ $ 779.6 Non-current liabilities ​ 1.5 ​ ​ 1.5 Total liabilities ​ 879.9 ​ ​ 781.1 Total AECOM deficit ​ (3.7) ​ ​ (54.9) Noncontrolling interests ​ 178.3 ​ ​ 156.0 Total owners’ equity ​ 174.6 ​ ​ 101.1 Total liabilities and owners’ equity ​ $ 1,054.5 ​ $ 882.2
Schedule of financial information of the unconsolidated joint ventures, as derived from their unaudited financial statements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ September 30, ​ 2024 2023 ​ ​ (in millions) Current assets ​ $ 1,201.8 ​ $ 1,177.4 Non-current assets ​ 1,052.8 ​ ​ 996.3 Total assets ​ $ 2,254.6 ​ $ 2,173.7 ​ ​ ​ ​ ​ ​ ​ Current liabilities ​ $ 624.7 ​ $ 605.9 Non-current liabilities ​ 434.2 ​ ​ 441.7 Total liabilities ​ 1,058.9 ​ ​ 1,047.6 Joint ventures’ equity ​ 1,195.7 ​ ​ 1,126.1 Total liabilities and joint ventures’ equity ​ $ 2,254.6 ​ $ 2,173.7 ​ ​ ​ ​ ​ ​ AECOM’s investment in unconsolidated joint ventures ​ $ 137.4 ​ $ 139.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ March 31, ​ March 31, ​ 2024 2023 ​ ​ (in millions) Revenue ​ $ 696.4 ​ $ 642.1 Cost of revenue ​ 645.9 ​ ​ 586.9 Gross profit ​ $ 50.5 ​ $ 55.2 Net income ​ $ 50.7 ​ $ 51.9
Schedule of AECOM's equity in earnings of unconsolidated joint ventures	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ March 31, March 31, ​ 2024 2023 ​ (in millions) Pass-through joint ventures ​ $ 17.6 ​ $ 14.5 Other joint ventures ​ (27.1) ​ ​ 2.8 Total ​ $ (9.5) ​ $ 17.3 ​

Pension Benefit Obligations (Ta

Pension Benefit Obligations (Tables)	6 Months Ended
	Mar. 31, 2024
Pension Benefit Obligations
Schedule of components of net periodic cost for the Company's pension and post-retirement plans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ March 31, 2024 ​ March 31, 2023 ​ March 31, 2024 ​ March 31, 2023 ​ U.S. Int’l U.S. Int’l U.S. Int’l U.S. Int’l ​ ​ (in millions) Components of net periodic benefit cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service costs ​ $ — ​ $ — ​ $ — ​ $ 0.1 ​ $ — ​ $ 0.1 ​ $ — ​ $ 0.2 Interest cost on projected benefit obligation ​ 2.5 ​ ​ 10.9 ​ ​ 2.4 ​ ​ 11.9 ​ ​ 4.9 ​ ​ 21.6 ​ ​ 4.9 ​ ​ 23.4 Expected return on plan assets ​ (1.4) ​ ​ (14.2) ​ ​ (1.4) ​ ​ (15.1) ​ ​ (2.8) ​ ​ (28.3) ​ ​ (2.9) ​ ​ (29.8) Amortization of net loss (gain) ​ 0.7 ​ ​ (0.6) ​ ​ 0.8 ​ ​ (0.2) ​ ​ 1.5 ​ ​ (1.2) ​ ​ 1.7 ​ ​ (0.3) Net periodic benefit cost (credit) ​ $ 1.8 ​ $ (3.9) ​ $ 1.8 ​ $ (3.3) ​ $ 3.6 ​ $ (7.8) ​ $ 3.7 ​ $ (6.5)

Debt (Tables)

Debt (Tables)	6 Months Ended
	Mar. 31, 2024
Debt
Schedule of debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ September 30, ​ 2024 2023 ​ ​ (in millions) Credit Agreement ​ $ 1,105.1 ​ $ 1,119.8 2027 Senior Notes ​ ​ 997.3 ​ ​ 997.3 Other debt ​ 103.5 ​ ​ 100.2 Total debt ​ 2,205.9 ​ ​ 2,217.3 Less: Current portion of debt and short-term borrowings ​ (91.5) ​ ​ (89.5) Less: Unamortized debt issuance costs ​ ​ (12.0) ​ ​ (14.4) Long-term debt ​ $ 2,102.4 ​ $ 2,113.4
Schedule of maturities of debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ September 30, ​ 2024 2023 ​ ​ (in millions) Credit Agreement ​ $ 1,105.1 ​ $ 1,119.8 2027 Senior Notes ​ ​ 997.3 ​ ​ 997.3 Other debt ​ 103.5 ​ ​ 100.2 Total debt ​ 2,205.9 ​ ​ 2,217.3 Less: Current portion of debt and short-term borrowings ​ (91.5) ​ ​ (89.5) Less: Unamortized debt issuance costs ​ ​ (12.0) ​ ​ (14.4) Long-term debt ​ $ 2,102.4 ​ $ 2,113.4 ​ The following table presents, in millions, scheduled maturities of the Company’s debt as of March 31, 2024: ​ ​ ​ ​ ​ Fiscal Year ​ ​ 2024 (six months remaining) ​ $ 63.3 2025 ​ ​ 54.4 2026 ​ ​ 417.3 2027 ​ ​ 1,013.7 2028 ​ ​ 657.2 Total ​ $ 2,205.9 ​

Derivative Financial Instrume_2

Derivative Financial Instruments and Fair Value Measurements (Tables)	6 Months Ended
	Mar. 31, 2024
Derivative Financial Instruments and Fair Value Measurements
Schedule of notional principle, fixed rates and related expiration dates of outstanding interest rate swap agreements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 Notional Amount ​ Notional Amount ​ Fixed ​ Effective ​ Expiration Currency (in millions) Rate Date Date USD ​ 400.0 ​ 1.283% ​ February 2023 ​ March 2028 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 Notional Amount ​ Notional Amount ​ Fixed ​ Effective ​ Expiration Currency (in millions) Rate Date Date USD ​ 400.0 1.283% ​ February 2023 ​ March 2028

Share-based Payments (Tables)

Share-based Payments (Tables)	6 Months Ended
	Mar. 31, 2024
Share-based Payments
Schedule of restricted stock units and PEP units activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 ​ ​ Weighted ​ Weighted ​ Weighted ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Average ​ ​ Restricted ​ Grant-Date ​ ​ ​ Grant-Date ​ Restricted ​ Grant-Date ​ ​ ​ Grant-Date ​ ​ Stock Units ​ Fair Value ​ PEP Units ​ Fair Value ​ Stock Units ​ Fair Value ​ PEP Units ​ Fair Value ​ ​ (in millions) ​ ​ ​ ​ (in millions) ​ ​ ​ ​ (in millions) ​ ​ ​ ​ (in millions) ​ ​ ​ Outstanding at September 30, ​ 0.8 ​ $ 68.34 ​ 0.7 ​ $ 75.54 ​ 1.0 ​ $ 53.05 ​ 0.7 ​ $ 60.60 Granted ​ 0.3 ​ $ 92.32 ​ 0.2 ​ $ 104.82 ​ 0.3 ​ $ 83.64 ​ 0.2 ​ $ 94.65 PEP units earned — ​ $ — ​ 0.2 ​ $ 52.49 ​ — ​ $ — ​ 0.2 ​ $ 43.19 Vested (0.3) ​ $ 49.99 ​ (0.4) ​ $ 52.49 ​ (0.4) ​ $ 44.95 ​ (0.4) ​ $ 43.19 Outstanding at March 31, 0.8 ​ $ 83.90 ​ 0.7 ​ $ 95.37 ​ 0.9 ​ $ 65.75 ​ 0.7 ​ $ 75.53

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Mar. 31, 2024
Earnings Per Share
Schedule of reconciliation of the denominators for basic and diluted EPS	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ March 31, ​ March 31, March 31, March 31, ​ 2024 2023 2024 2023 ​ ​ (in millions) Denominator for basic earnings per share ​ 136.0 ​ 138.9 ​ 136.0 ​ 138.8 Potential common shares ​ 0.7 ​ 1.4 ​ 0.9 ​ 1.7 Denominator for diluted earnings per share ​ 136.7 ​ 140.3 ​ 136.9 ​ 140.5 ​

Leases (Tables)

Leases (Tables)	6 Months Ended
	Mar. 31, 2024
Leases
Schedule of components of lease expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ March 31, 2024 March 31, 2023 March 31, 2024 March 31, 2023 ​ ​ (in millions) Operating lease cost ​ $ 37.7 ​ $ 41.6 ​ $ 75.1 ​ $ 83.1 Finance lease cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ 7.3 ​ ​ 5.7 ​ ​ 14.1 ​ ​ 10.8 Interest on lease liabilities ​ 0.7 ​ ​ 0.6 ​ ​ 1.5 ​ ​ 1.2 Variable lease cost ​ 8.6 ​ ​ 8.6 ​ ​ 17.5 ​ ​ 16.5 Total lease cost ​ $ 54.3 ​ $ 56.5 ​ $ 108.2 ​ $ 111.6
Schedule of additional balance sheet information related to leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of (in millions except as noted) Balance Sheet Classification March 31, 2024 September 30, 2023 Assets: ​ ​ ​ ​ Operating lease assets Operating lease right-of-use assets ​ $ 422.9 ​ $ 447.0 Finance lease assets Property and equipment – net ​ ​ 69.1 ​ ​ 64.8 Total lease assets ​ $ 492.0 ​ $ 511.8 ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ Current: ​ ​ ​ ​ ​ ​ Operating lease liabilities Accrued expenses and other current liabilities ​ $ 142.0 ​ $ 139.8 Finance lease liabilities Current portion of long-term debt ​ ​ 27.3 ​ ​ 25.0 Total current lease liabilities ​ ​ 169.3 ​ ​ 164.8 Non-current: ​ ​ ​ ​ ​ ​ Operating lease liabilities Operating lease liabilities, noncurrent ​ ​ 507.5 ​ ​ 548.9 Finance lease liabilities Long-term debt ​ ​ 41.3 ​ ​ 39.8 Total non-current lease liabilities ​ $ 548.8 ​ $ 588.7 ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ March 31, 2024 September 30, 2023 ​ Weighted average remaining lease term (in years): ​ ​ ​ Operating leases 6.2 ​ 6.4 ​ Finance leases 2.8 ​ 2.9 ​ Weighted average discount rates: ​ ​ ​ ​ Operating leases 5.0 % 4.3 % Finance leases 4.3 % 4.1 %
Schedule of additional cash flow information related to leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ March 31, ​ March 31, ​ 2024 2023 ​ ​ (in millions) Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 92.7 ​ $ 94.8 Operating cash flows from finance leases ​ ​ 1.6 ​ ​ 1.2 Financing cash flows from finance leases ​ ​ 15.1 ​ ​ 11.3 Right-of-use assets obtained in exchange for new operating leases ​ ​ 38.0 ​ ​ 66.4 Right-of-use assets obtained in exchange for new finance leases ​ ​ 17.9 ​ ​ 19.6
Schedule of total remaining lease payments under the Company's operating and finance leases	​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Finance Leases Fiscal Year ​ (in millions) 2024 (six months remaining) ​ $ 89.3 ​ $ 15.5 2025 ​ 152.4 ​ ​ 26.6 2026 ​ 121.3 ​ ​ 19.4 2027 ​ 92.2 ​ ​ 10.4 2028 ​ ​ 79.9 ​ ​ 1.3 Thereafter ​ 223.5 ​ ​ — Total lease payments ​ $ 758.6 ​ $ 73.2 Less: Amounts representing interest ​ $ (109.1) ​ $ (4.6) Total lease liabilities ​ $ 649.5 ​ $ 68.6 ​

Other Financial Information (Ta

Other Financial Information (Tables)	6 Months Ended
	Mar. 31, 2024
Other Financial Information
Schedule of accrued expenses and other current liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, September 30, ​ ​ 2024 ​ 2023 ​ ​ (in millions) Accrued salaries and benefits ​ $ 569.6 ​ $ 599.8 Accrued contract costs ​ 1,416.7 ​ ​ 1,340.4 Other accrued expenses ​ 398.9 ​ ​ 347.3 Total ​ $ 2,385.2 ​ $ 2,287.5

Reclassifications out of Accu_2

Reclassifications out of Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Mar. 31, 2024
Reclassifications out of Accumulated Other Comprehensive Loss
Schedule of accumulated balances and reporting period activities related to reclassifications out of accumulated other comprehensive loss	The accumulated balances and reporting period activities for the three and six months ended March 31, 2024 and 2023 related to reclassifications out of accumulated other comprehensive loss are summarized as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ Related Translation Derivative Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at December 31, 2023 ​ $ (235.0) ​ $ (679.7) ​ $ 24.9 ​ $ (889.8) Other comprehensive income (loss) before reclassification ​ 1.9 ​ ​ (27.0) ​ ​ 8.3 ​ ​ (16.8) Amounts reclassified from accumulated other comprehensive loss ​ 0.1 ​ ​ — ​ ​ (3.5) ​ ​ (3.4) Balances at March 31, 2024 ​ $ (233.0) ​ $ (706.7) ​ $ 29.7 ​ $ (910.0) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at December 31, 2022 ​ $ (232.1) ​ $ (721.4) ​ $ 35.1 ​ $ (918.4) Other comprehensive (loss) income before reclassification ​ ​ (4.2) ​ ​ 8.5 ​ ​ (5.6) ​ ​ (1.3) Amounts reclassified from accumulated other comprehensive income (loss) ​ 0.5 ​ ​ — ​ ​ (1.9) ​ ​ (1.4) Balances at March 31, 2023 ​ $ (235.8) ​ $ (712.9) ​ $ 27.6 ​ $ (921.1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at September 30, 2023 ​ $ (226.0) ​ $ (739.7) ​ $ 39.1 ​ $ (926.6) Other comprehensive (loss) income before reclassification ​ ​ (7.2) ​ ​ 33.0 ​ ​ (2.3) ​ ​ 23.5 Amounts reclassified from accumulated other comprehensive loss ​ ​ 0.2 ​ ​ — ​ ​ (7.1) ​ ​ (6.9) Balances at March 31, 2024 ​ $ (233.0) ​ $ (706.7) ​ $ 29.7 ​ $ (910.0) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at September 30, 2022 ​ $ (217.3) ​ $ (799.3) ​ $ 36.9 ​ $ (979.7) Other comprehensive (loss) income before reclassification ​ (19.6) ​ ​ 86.4 ​ ​ (7.4) ​ ​ 59.4 Amounts reclassified from accumulated other comprehensive income (loss) ​ ​ 1.1 ​ ​ — ​ ​ (1.9) ​ ​ (0.8) Balances at March 31, 2023 ​ $ (235.8) ​ $ (712.9) ​ $ 27.6 ​ $ (921.1) ​

Reportable Segments (Tables)

Reportable Segments (Tables)	6 Months Ended
	Mar. 31, 2024
Reportable Segments
Summary of financial information concerning the Company's reportable segments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ AECOM ​ ​ ​ ​ ​ ​ ​ Reportable Segments: Americas International Capital Corporate Total ​ ​ ​ ( $ in millions) Three Months Ended March 31, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 3,038.6 ​ $ 904.8 ​ $ 0.5 ​ $ — ​ $ 3,943.9 ​ Gross profit ​ ​ 184.4 ​ ​ 76.2 ​ ​ 0.5 ​ ​ — ​ ​ 261.1 ​ Equity in earnings of joint ventures ​ ​ 4.8 ​ ​ 5.0 ​ ​ 9.7 ​ ​ — ​ ​ 19.5 ​ General and administrative expenses ​ ​ — ​ ​ — ​ ​ (9.7) ​ ​ (35.0) ​ ​ (44.7) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (35.4) ​ ​ (35.4) ​ Operating income ​ ​ 189.2 ​ ​ 81.2 ​ ​ 0.5 ​ ​ (70.4) ​ ​ 200.5 ​ Gross profit as a % of revenue ​ 6.1 % ​ 8.4 % ​ ​ ​ ​ ​ ​ ​ 6.6 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 2,630.2 ​ $ 859.8 ​ $ 0.1 ​ $ — ​ $ 3,490.1 ​ Gross profit ​ ​ 173.3 ​ ​ 54.7 ​ ​ 0.1 ​ ​ — ​ ​ 228.1 ​ Equity in earnings of joint ventures ​ ​ 4.9 ​ ​ 5.4 ​ ​ (2.8) ​ ​ — ​ ​ 7.5 ​ General and administrative expenses ​ ​ — ​ ​ — ​ ​ (2.9) ​ ​ (31.3) ​ ​ (34.2) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (3.9) ​ ​ (3.9) ​ Operating income (loss) ​ ​ 178.2 ​ ​ 60.1 ​ ​ (5.6) ​ ​ (35.2) ​ ​ 197.5 ​ Gross profit as a % of revenue ​ 6.6 % ​ 6.4 % ​ ​ ​ ​ ​ ​ ​ 6.5 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended March 31, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 6,077.3 ​ $ 1,765.8 ​ $ 0.7 ​ $ — ​ $ 7,843.8 ​ Gross profit ​ ​ 355.4 ​ ​ 149.0 ​ ​ 0.7 ​ ​ — ​ ​ 505.1 ​ Equity in earnings of joint ventures ​ ​ 8.4 ​ ​ 9.3 ​ ​ (27.2) ​ ​ — ​ ​ (9.5) ​ General and administrative expenses ​ ​ — ​ ​ — ​ ​ (12.1) ​ ​ (68.3) ​ ​ (80.4) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (51.6) ​ ​ (51.6) ​ Operating income (loss) ​ ​ 363.8 ​ ​ 158.3 ​ ​ (38.6) ​ ​ (119.9) ​ ​ 363.6 ​ Gross profit as a % of revenue ​ ​ 5.8 % ​ 8.4 % ​ ​ ​ ​ ​ ​ ​ 6.4 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 5,209.5 ​ $ 1,662.6 ​ $ 0.4 ​ $ — ​ $ 6,872.5 ​ Gross profit ​ ​ 336.2 ​ ​ 106.5 ​ ​ 0.4 ​ ​ — ​ ​ 443.1 ​ Equity in earnings of joint ventures ​ ​ 5.8 ​ ​ 8.7 ​ ​ 2.8 ​ ​ — ​ ​ 17.3 ​ General and administrative expenses ​ ​ — ​ ​ — ​ ​ (5.6) ​ ​ (64.2) ​ ​ (69.8) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (41.4) ​ ​ (41.4) ​ Operating income (loss) ​ ​ 342.0 ​ ​ 115.2 ​ ​ (2.4) ​ ​ (105.6) ​ ​ 349.2 ​ Gross profit as a % of revenue ​ 6.5 % ​ 6.4 % ​ ​ ​ ​ ​ ​ ​ 6.4 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reportable Segments: ​ ​ ​ ​ ​ Total assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 ​ $ 7,754.4 ​ $ 2,671.4 ​ $ 53.2 ​ $ 873.3 ​ ​ September 30, 2023 ​ $ 7,433.1 ​ $ 2,536.2 ​ $ 64.5 ​ $ 1,104.4 ​ ​ ​

Basis of Presentation (Details)

Basis of Presentation (Details)	6 Months Ended
	Mar. 31, 2024
Minimum
Basis of presentation
Length of fiscal year	364 days
Maximum
Basis of presentation
Length of fiscal year	371 days

Discontinued Operations, Good_3

Discontinued Operations, Goodwill, and Intangible Assets - Sale of businesses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Held for sale | Oil and gas construction business
Discontinued Operations, Goodwill and Intangible Assets
Amount of cash payment for contingent consideration collected	$ 103.1	$ 38.9

Discontinued Operations, Good_4

Discontinued Operations, Goodwill, and Intangible Assets - Balance sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Summary of financial information of the Disposal Group is as follows:
Long-term liabilities held for sale	$ 796	$ 792
Held for sale
Summary of financial information of the Disposal Group is as follows:
Cash and cash equivalents	3,300	1,900
Receivables and contract assets	101,300	93,300
Other	500
Current assets held for sale	105,100	95,200
Property and equipment, net	15,800	14,200
Write-down of assets to fair value less cost to sell	(15,800)	(14,200)
Accounts payable and accrued expenses	51,100	45,600
Current liabilities held for sale	51,100	45,600
Long-term liabilities held for sale	$ 800	$ 800

Discontinued Operations, Good_5

Discontinued Operations, Goodwill, and Intangible Assets - Income statement information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Discontinued Operations, Goodwill and Intangible Assets
Net loss from discontinuing operations	$ (109,388)	$ (41,775)	$ (110,675)	$ (42,163)
Held for sale
Discontinued Operations, Goodwill and Intangible Assets
Revenue	46,500	58,800	101,100	100,500
Cost of revenue	45,000	62,100	97,700	102,400
Gross profit	1,500	(3,300)	3,400	(1,900)
Equity in earnings of joint ventures	(3,400)		(3,400)	(1,700)
Loss on disposal activities	(109,600)	(40,200)	(113,100)	(40,200)
Transaction costs	(200)		(200)	(200)
Loss from operations	(111,700)	(43,500)	(113,300)	(44,000)
Other loss	(500)		(1,100)
Loss before taxes	(112,200)	(43,500)	(114,400)	(44,000)
Income tax benefit	(2,800)	(1,700)	(3,700)	(1,800)
Net loss from discontinuing operations	$ (109,400)	$ (41,800)	$ (110,700)	$ (42,200)

Discontinued Operations, Good_6

Discontinued Operations, Goodwill, and Intangible Assets - Statement of cash flows (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Held for sale
Discontinued Operations, Goodwill and Intangible Assets
Payments for capital expenditures	$ 2.1	$ 0.5	$ 2.1	$ 4.5

Discontinued Operations, Good_7

Discontinued Operations, Goodwill, and Intangible Assets - Goodwill by segments (Details) $ in Thousands	6 Months Ended
	Mar. 31, 2024 USD ($)
Changes in the carrying value of goodwill by reporting segment
Goodwill at the beginning of the period	$ 3,418,930
Foreign exchange impact	15,900
Acquired	12,200
Goodwill at the end of the period	3,446,984
Americas
Changes in the carrying value of goodwill by reporting segment
Goodwill at the beginning of the period	2,614,000
Foreign exchange impact	500
Acquired	12,200
Goodwill at the end of the period	2,626,700
International
Changes in the carrying value of goodwill by reporting segment
Goodwill at the beginning of the period	804,900
Foreign exchange impact	15,400
Goodwill at the end of the period	$ 820,300

Discontinued Operations, Good_8

Discontinued Operations, Goodwill, and Intangible Assets - Intangible assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Discontinued Operations, Goodwill and Intangible Assets
Intangible Assets, Net	$ 16,111	$ 17,769
Backlog and Customer relationships
Discontinued Operations, Goodwill and Intangible Assets
Gross Amount	671,500	663,800
Accumulated Amortization	(655,400)	(646,000)
Intangible Assets, Net	$ 16,100	$ 17,800
Backlog and Customer relationships | Minimum
Discontinued Operations, Goodwill and Intangible Assets
Amortization Period	1 year
Backlog and Customer relationships | Maximum
Discontinued Operations, Goodwill and Intangible Assets
Amortization Period	11 years

Discontinued Operations, Good_9

Discontinued Operations, Goodwill, and Intangible Assets - Amortization expense (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Sep. 30, 2023
Discontinued Operations, Goodwill, and Intangible Assets
Amortization expense	$ 9,400	$ 9,300
Discontinued Operations, Goodwill and Intangible Assets
2024 (six months remaining)	9,200
2025	2,100
2026	1,500
2027	1,500
2028	1,500
Thereafter	300
Intangible Assets, Net	$ 16,111		$ 17,769

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Billions	6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
ASU 2014-09
Revenue Recognition
Passed through costs included in revenue and cost of sales	$ 4.3	$ 3.6

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregated revenues (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Revenue Recognition
Total revenue	$ 3,943.9	$ 3,490.1	$ 7,843.8	$ 6,872.5
Americas
Revenue Recognition
Total revenue	3,039.1	2,630.3	6,077.9	5,209.9
Europe, Middle East, India, Africa
Revenue Recognition
Total revenue	619.8	494.1	1,115.2	942.1
Asia-Australia-Pacific
Revenue Recognition
Total revenue	285	365.7	650.7	720.5
Cost reimbursable
Revenue Recognition
Total revenue	1,605.1	1,511.3	3,222.3	3,026.2
Guaranteed maximum price
Revenue Recognition
Total revenue	1,420.7	1,151	2,835.6	2,239.2
Fixed-price
Revenue Recognition
Total revenue	$ 918.1	$ 827.8	$ 1,785.9	$ 1,607.1

Revenue Recognition - Performan

Revenue Recognition - Performance obligations (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue Recognition
Performance obligation	$ 21,400
Recognized revenue	$ 685.3	$ 696.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue Recognition
Performance obligation, percent to be satisfied	55%
Performance obligation expected timing of satisfaction period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue Recognition
Performance obligation expected timing of satisfaction period	2 years

Revenue Recognition - Accounts

Revenue Recognition - Accounts receivable, net (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2024	Sep. 30, 2023
Billed	$ 2,125,400	$ 2,122,200
Contract retentions	602,800	516,500
Total accounts receivable-gross	2,728,200	2,638,700
Allowance for doubtful accounts and credit losses	(81,500)	(94,200)
Total accounts receivable-net	$ 2,646,722	$ 2,544,453
Additional disclosures
Unbilled receivables are expected to be billed and collected (in months)	12 months	12 months
Significant claims recorded in contract assets and other non-current assets	$ 170,000	$ 160,000
Trade receivables sold with no financial and legal obligations	$ 291,900	$ 291,000
Outstanding receivables
Additional disclosures
Number of customers accounting for 10%	No	No
Concentration Risk Threshold Percentage	10%	10%

Joint Ventures and Variable I_3

Joint Ventures and Variable Interest Entities - Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Joint Ventures and Variable Interest Entities
Current assets	$ 6,497,786		$ 6,497,786			$ 6,169,511
TOTAL ASSETS	11,457,393		11,457,393			11,233,398
Current liabilities	6,136,115		6,136,115			5,850,283
TOTAL LIABILITIES	9,063,038		9,063,038			8,849,687
Total AECOM deficit	2,198,667		2,198,667			2,212,332
Noncontrolling interests	195,688		195,688			171,379
TOTAL STOCKHOLDERS' EQUITY	2,394,355	$ 2,736,875	2,394,355	$ 2,736,875	$ 2,428,218	2,383,711	$ 2,692,893	$ 2,605,379
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	11,457,393		11,457,393			11,233,398
Revenue	3,943,833	$ 3,490,172	7,843,753	6,872,527
Consolidated joint ventures
Joint Ventures and Variable Interest Entities
Current assets	970,000		970,000			806,300
Non-current assets	84,500		84,500			75,900
TOTAL ASSETS	1,054,500		1,054,500			882,200
Current liabilities	878,400		878,400			779,600
Non-current liabilities	1,500		1,500			1,500
TOTAL LIABILITIES	879,900		879,900			781,100
Total AECOM deficit	(3,700)		(3,700)			(54,900)
Noncontrolling interests	178,300		178,300			156,000
TOTAL STOCKHOLDERS' EQUITY	174,600		174,600			101,100
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 1,054,500		1,054,500			$ 882,200
Revenue			$ 1,171,400	$ 941,700

Joint Ventures and Variable I_4

Joint Ventures and Variable Interest Entities - Unconsolidated (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Financial Information
Current assets	$ 6,497,786		$ 6,497,786			$ 6,169,511
TOTAL ASSETS	11,457,393		11,457,393			11,233,398
Current liabilities	6,136,115		6,136,115			5,850,283
TOTAL LIABILITIES	9,063,038		9,063,038			8,849,687
Joint ventures' equity	2,394,355	$ 2,736,875	2,394,355	$ 2,736,875	$ 2,428,218	2,383,711	$ 2,692,893	$ 2,605,379
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	11,457,393		11,457,393			11,233,398
AECOM's investment in unconsolidated joint ventures	137,422		137,422			139,236
Joint ventures summarized financial information
Revenue	3,943,833	3,490,172	7,843,753	6,872,527
Cost of revenue	3,682,659	3,262,078	7,338,609	6,429,445
Gross profit	261,174	228,094	505,144	443,082
Net income	16,030	$ 84,483	124,624	181,246
Unconsolidated joint ventures
Financial Information
Current assets	1,201,800		1,201,800			1,177,400
Non-current assets	1,052,800		1,052,800			996,300
TOTAL ASSETS	2,254,600		2,254,600			2,173,700
Current liabilities	624,700		624,700			605,900
Non-current liabilities	434,200		434,200			441,700
TOTAL LIABILITIES	1,058,900		1,058,900			1,047,600
Joint ventures' equity	1,195,700		1,195,700			1,126,100
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	2,254,600		2,254,600			2,173,700
AECOM's investment in unconsolidated joint ventures	$ 137,400		137,400			$ 139,200
Joint ventures summarized financial information
Revenue			696,400	642,100
Cost of revenue			645,900	586,900
Gross profit			50,500	55,200
Net income			$ 50,700	$ 51,900

Joint Ventures and Variable I_5

Joint Ventures and Variable Interest Entities - Equity in Earnings (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Financial Information
Equity in earnings (losses) of joint ventures	$ 19,459	$ 7,456	$ (9,482)	$ 17,285
Unconsolidated joint ventures
Financial Information
Equity in earnings (losses) of joint ventures			(9,500)	17,300
Unconsolidated joint ventures | Pass-through joint ventures
Financial Information
Equity in earnings (losses) of joint ventures			17,600	14,500
Unconsolidated joint ventures | Other joint ventures
Financial Information
Equity in earnings (losses) of joint ventures			$ (27,100)	$ 2,800

Pension Benefit Obligations (De

Pension Benefit Obligations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Percentage of Plan Assets:
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income	Other Nonoperating Income	Other Nonoperating Income	Other Nonoperating Income
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income	Other Nonoperating Income	Other Nonoperating Income	Other Nonoperating Income
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income	Other Nonoperating Income	Other Nonoperating Income	Other Nonoperating Income
United States
Percentage of Plan Assets:
Interest cost on projected benefit obligation	$ 2.5	$ 2.4	$ 4.9	$ 4.9
Expected return on plan assets	(1.4)	(1.4)	(2.8)	(2.9)
Amortization of net loss (gain)	0.7	0.8	1.5	1.7
Net periodic benefit cost (credit)	1.8	1.8	3.6	3.7
Change in benefit obligation:
Employer contributions			4.4
Expected remaining scheduled annual employer contributions for the current fiscal year	8.5		8.5
International
Percentage of Plan Assets:
Service costs		0.1	0.1	0.2
Interest cost on projected benefit obligation	10.9	11.9	21.6	23.4
Expected return on plan assets	(14.2)	(15.1)	(28.3)	(29.8)
Amortization of net loss (gain)	(0.6)	(0.2)	(1.2)	(0.3)
Net periodic benefit cost (credit)	(3.9)	$ (3.3)	(7.8)	$ (6.5)
Change in benefit obligation:
Employer contributions			13.1
Expected remaining scheduled annual employer contributions for the current fiscal year	$ 12.6		$ 12.6

Debt - Long-term debt (Details)

Debt - Long-term debt (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Debt
Total debt	$ 2,205,900	$ 2,217,300
Less: Current portion of debt and short-term borrowings	(91,500)	(89,500)
Less: Unamortized debt issuance costs	(12,000)	(14,400)
Long-term debt	2,102,358	2,113,369
Credit Agreement
Debt
Total debt	1,105,100	1,119,800
2027 Senior Notes
Debt
Total debt	997,300	997,300
Other Debt
Debt
Total debt	$ 103,500	$ 100,200

Debt - Scheduled Maturities (De

Debt - Scheduled Maturities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Sep. 30, 2023
Debt
2024 (six months remaining)	$ 63.3
2025	54.4
2026	417.3
2027	1,013.7
2028	657.2
Total	$ 2,205.9	$ 2,217.3

Debt - Credit Agreement (Detail

Debt - Credit Agreement (Details)	Apr. 19, 2024 USD ($)	Mar. 31, 2024 USD ($)	Sep. 30, 2023 USD ($)	Jun. 25, 2021 USD ($)	Apr. 13, 2021 USD ($)	Feb. 08, 2021 USD ($)
New Term Loan B Facility | Base Rate
Debt agreements
Debt Instrument, Floor Rate	0%
Interest rate, basis spread (as a percent)	0.875%
New Term Loan B Facility | SOFR
Debt agreements
Debt Instrument, Floor Rate	0%
Debt Instrument, Spread Adjustment Rate	0%
Interest rate, basis spread (as a percent)	1.875%
New Revolving Credit Facility | Other Currency
Debt agreements
Interest rate, basis spread (as a percent)	1.25%
New Revolving Credit Facility | Base Rate | USD
Debt agreements
Debt Instrument, Floor Rate	0%
Interest rate, basis spread (as a percent)	0.25%
New Revolving Credit Facility | SOFR | USD
Debt agreements
Debt Instrument, Floor Rate	0%
Debt Instrument, Spread Adjustment Rate	0.10%
2014 Credit Agreement | Term loan A
Debt agreements
Maximum borrowing capacity				$ 215,000,000
Credit Agreement | SOFR | USD
Debt agreements
Interest rate, basis spread (as a percent)	1.25%
Credit Agreement | Maximum
Debt agreements
Consolidated leverage ratio						4
Credit Agreement | New Term Loan B Facility
Debt agreements
Maximum borrowing capacity	$ 700,000,000
Credit Agreement | New Term Loan A Facility
Debt agreements
Maximum borrowing capacity	750,000,000
Credit Agreement | Term loan A
Debt agreements
Maximum borrowing capacity						$ 246,968,737.50
Credit Agreement | Term B facility
Debt agreements
Maximum borrowing capacity					$ 700,000,000
Credit Agreement | Revolving credit facility
Debt agreements
Maximum borrowing capacity						$ 1,150,000,000
Outstanding letters of credit		$ 4,400,000	$ 4,400,000
Current borrowing capacity		$ 1,145,600,000	$ 1,145,600,000
Credit Agreement | New Revolving Credit Facility
Debt agreements
Maximum borrowing capacity	$ 1,500,000,000
2024 Senior Notes
Debt agreements
Cash tender offer to purchase					$ 700,000,000
Interest rate (as a percent)				5.875%	5.875%

Debt - 2027 Senior Notes (Detai

Debt - 2027 Senior Notes (Details) - 2027 Senior Notes - USD ($)	Feb. 21, 2017	Mar. 31, 2024
Debt
Face amount	$ 1,000,000,000
Interest rate (as a percent)	5.125%
Fair value of debt instrument		$ 977,300,000
At any time and from time to time prior to December 15, 2026
Debt
Redemption price (in percent)	100%
At any time on or after December 15, 2026
Debt
Redemption price (in percent)	100%

Debt - Other Debt and Other Ite

Debt - Other Debt and Other Items (Details) - Other Debt - USD ($) $ in Millions	Mar. 31, 2024	Sep. 30, 2023
Unsecured
Debt
Current borrowing capacity	$ 418.9
Standby Letters of Credit
Debt
Outstanding letters of credit	$ 895.3	$ 878.9

Debt - Effective Interest Rate

Debt - Effective Interest Rate (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Debt
Effective interest rate including effects of interest rate swap agreements	5.50%	5.20%	5.50%	5.20%
Amortization of deferred debt issuance costs	$ 1.2	$ 1.2	$ 2.4	$ 2.4

Derivative Financial Instrume_3

Derivative Financial Instruments and Fair Value Measurements - Cash Flow Hedges (Details) - Cash Flow Hedging - USD ($) $ in Millions	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2022	Sep. 30, 2021
Interest Rate Cap
Derivative financial instruments
Notional Amount			$ 300
Interest Rate Cap | Maximum
Derivative financial instruments
Fixed Rate (as a percent)			3.465%
Interest Rate Swap
Derivative financial instruments
Notional Amount				$ 400
Fixed Rate (as a percent)				1.283%
Spread Rate (as a percent)			3.465%
Designated as Hedging Instrument | Interest Rate Swap | USD | February 2023
Derivative financial instruments
Notional Amount	$ 400	$ 400
Fixed Rate (as a percent)	1.283%	1.283%

Derivative Financial Instrume_4

Derivative Financial Instruments and Fair Value Measurements - Fair Value Measurements (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2024	Sep. 30, 2023
Interest Rate Swap and Interest Rate Cap | Other current assets
Derivative financial instruments
Fair values of the interest rate swap and cap agreements	$ 15.2	$ 17.2
Interest Rate Swap and Interest Rate Cap | Other non-current assets
Derivative financial instruments
Fair values of the interest rate swap and cap agreements	27.1	$ 37.5
Interest Rate Swap and Interest Rate Cap | Other Noncurrent Liabilities
Derivative financial instruments
Fair values of the interest rate swap and cap agreements	0.6
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swap
Derivative financial instruments
Losses recognized in income	$ 0

Share-Based Payments - Restrict

Share-Based Payments - Restricted stock unit, PEP unit, and Stock Option activity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	6 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Sep. 30, 2023
Other disclosures
Unrecognized compensation expense	$ 78.7		$ 48.3
Recognition period of unrecognized compensation expense	3 years		3 years
Restricted Stock Units
Units
Outstanding at beginning (in units)	0.8	1	1
Granted (in units)	0.3	0.3
Vested (in shares)	(0.3)	(0.4)
Outstanding at ending (in units)	0.8	0.9	0.8
Weighted Average Grant-Date Fair Value
Outstanding at beginning (in USD per unit)	$ 68.34	$ 53.05	$ 53.05
Granted (in USD per unit)	92.32	83.64
Vested (in USD per unit)	49.99	44.95
Outstanding at ending (in USD per unit)	$ 83.90	$ 65.75	$ 68.34
Other disclosures
Compensation expense related to share-based payments	$ 30.6	$ 24.6
PEP Units
Share-based Payments
Vesting period	3 years
Units
Outstanding at beginning (in units)	0.7	0.7	0.7
Granted (in units)	0.2	0.2
PEP units earned (in units)	0.2	0.2
Vested (in shares)	(0.4)	(0.4)
Outstanding at ending (in units)	0.7	0.7	0.7
Weighted Average Grant-Date Fair Value
Outstanding at beginning (in USD per unit)	$ 75.54	$ 60.60	$ 60.60
Granted (in USD per unit)	104.82	94.65
PEP units earned (in USD per unit)	52.49	43.19
Vested (in USD per unit)	52.49	43.19
Outstanding at ending (in USD per unit)	$ 95.37	$ 75.53	$ 75.54

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Taxes
Effective tax rate (as a percent)	23.40%	23.10%
Tax expense related to state income taxes	$ 12.3	$ 9
Tax at federal statutory rate (as a percent)	21%	21%
Tax benefit related to income tax credits and incentives	$ 29.4	$ 23.6
Tax expense related to foreign residual income	26.2	$ 19.1
Tax expense related to audit settlement	6.9
Tax expense related to valuation allowances	6.6
Gross book-tax differences from non-U.S. subsidiaries	$ 1,300

Earnings Per Share (Details)

Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share
Denominator for basic earnings per share	136,006	138,927	135,952	138,807
Potential common shares	700	1,400	900	1,700
Denominator for diluted earnings per share	136,712	140,335	136,907	140,489

Leases - Components of lease ex

Leases - Components of lease expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Operating lease cost
Operating lease cost	$ 37.7	$ 41.6	$ 75.1	$ 83.1
Finance lease cost
Amortization of right-of-use assets	7.3	5.7	14.1	10.8
Interest on lease liabilities	0.7	0.6	1.5	1.2
Variable lease cost	8.6	8.6	17.5	16.5
Total lease cost	$ 54.3	$ 56.5	$ 108.2	$ 111.6

Leases - Additional balance she

Leases - Additional balance sheet information (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Assets:
Operating lease assets	$ 422,850	$ 447,044
Balance Sheet classification of operating lease assets	Operating lease assets	Operating lease assets
Finance lease assets	$ 69,100	$ 64,800
Balance Sheet classification of finance lease assets	PROPERTY AND EQUIPMENT-NET	PROPERTY AND EQUIPMENT-NET
Total lease assets	$ 492,000	$ 511,800
Current:
Operating lease liabilities	$ 142,000	$ 139,800
Balance Sheet classification of operating lease liabilities	Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Finance lease liabilities	$ 27,300	$ 25,000
Balance Sheet classification of finance lease liabilities	Current portion of long-term debt	Current portion of long-term debt
Total current lease liabilities	$ 169,300	$ 164,800
Non-current:
Operating lease liabilities	$ 507,518	$ 548,851
Balance Sheet classification of operating lease liabilities	Operating lease liabilities	Operating lease liabilities
Finance lease liabilities	$ 41,300	$ 39,800
Balance Sheet classification of finance lease liabilities	LONG-TERM DEBT	LONG-TERM DEBT
Total non-current lease liabilities	$ 548,800	$ 588,700
Weighted average remaining lease term (in years):
Operating leases	6 years 2 months 12 days	6 years 4 months 24 days
Finance leases	2 years 9 months 18 days	2 years 10 months 24 days
Weighted average discount rates:
Operating leases	5%	4.30%
Finance leases	4.30%	4.10%

Leases - Additional cash flow i

Leases - Additional cash flow information (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 92.7	$ 94.8
Operating cash flows from finance leases	1.6	1.2
Financing cash flows from finance leases	15.1	11.3
Right-of-use assets obtained in exchange for new operating leases	38	66.4
Right-of-use assets obtained in exchange for new finance leases	$ 17.9	$ 19.6

Leases - Lease payments under o

Leases - Lease payments under operating lease (Details) $ in Millions	Mar. 31, 2024 USD ($)
Amounts payable under non-cancelable operating lease commitments
2024 (six months remaining)	$ 89.3
2025	152.4
2026	121.3
2027	92.2
2028	79.9
Thereafter	223.5
Total lease payments	758.6
Less: Amounts representing interest	(109.1)
Total lease liabilities	$ 649.5

Leases - Lease payments under f

Leases - Lease payments under finance lease (Details) $ in Millions	Mar. 31, 2024 USD ($)
Leases
2024 (six months remaining)	$ 15.5
2025	26.6
2026	19.4
2027	10.4
2028	1.3
Total lease payments	73.2
Less: Amounts representing interest	(4.6)
Total lease liabilities	$ 68.6

Other Financial Information (De

Other Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023	Mar. 21, 2024	Sep. 30, 2023
Accrued expenses and other current liabilities
Accrued salaries and benefits	$ 569,600		$ 569,600			$ 599,800
Accrued contract costs	1,416,700		1,416,700			1,340,400
Other accrued expenses	398,900		398,900			347,300
Total	2,385,201		2,385,201			2,287,546
Restructuring costs	35,465	$ 3,973	51,645	$ 41,432
Accrued restructuring expenses	7,300	$ 30,700	7,300	30,700
Dividend paid per share in cash					$ 0.22
Accrued and unpaid dividend	32,100		32,100
Personnel and other costs
Accrued expenses and other current liabilities
Restructuring costs			38,600	39,000
Real estate costs
Accrued expenses and other current liabilities
Restructuring costs			13,000	$ 2,400
Professional liability accrual
Accrued expenses and other current liabilities
Accrued contract costs	$ 793,800		$ 793,800			$ 809,600

Reclassifications out of Accu_3

Reclassifications out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Accumulated balances
Balance at the beginning of the period			$ (926,577)
Balance at the end of the period	$ (909,970)		(909,970)
Pension Related Adjustments
Accumulated balances
Balance at the beginning of the period	(235,000)	$ (232,100)	(226,000)	$ (217,300)
Other comprehensive (loss) income before reclassification	1,900	(4,200)	(7,200)	(19,600)
Amounts reclassified from accumulated other comprehensive income (loss)	100	500	200	1,100
Balance at the end of the period	(233,000)	(235,800)	(233,000)	(235,800)
Foreign Currency Translation Adjustments
Accumulated balances
Balance at the beginning of the period	(679,700)	(721,400)	(739,700)	(799,300)
Other comprehensive (loss) income before reclassification	(27,000)	8,500	33,000	86,400
Balance at the end of the period	(706,700)	(712,900)	(706,700)	(712,900)
Gain/(Loss) on Derivative Instruments
Accumulated balances
Balance at the beginning of the period	24,900	35,100	39,100	36,900
Other comprehensive (loss) income before reclassification	8,300	(5,600)	(2,300)	(7,400)
Amounts reclassified from accumulated other comprehensive income (loss)	(3,500)	(1,900)	(7,100)	(1,900)
Balance at the end of the period	29,700	27,600	29,700	27,600
Accumulated Other Comprehensive Loss
Accumulated balances
Balance at the beginning of the period	(889,800)	(918,400)	(926,600)	(979,700)
Other comprehensive (loss) income before reclassification	(16,800)	(1,300)	23,500	59,400
Amounts reclassified from accumulated other comprehensive income (loss)	(3,400)	(1,400)	(6,900)	(800)
Balance at the end of the period	$ (910,000)	$ (921,100)	$ (910,000)	$ (921,100)

Commitments and Contingencies -

Commitments and Contingencies - Commitments (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2024	Sep. 30, 2023
Standby letters of credit
Commitments and Contingencies
Outstanding standby letters of credit	$ 895.3	$ 878.9
Amount available	418.9
Contingency liability	899.7
Surety Bond
Commitments and Contingencies
Contingency liability	4,700
Fund investment capital
Commitments and Contingencies
Commitment	$ 7.1
Commitment period	5 years

Commitments and Contingencies_2

Commitments and Contingencies - DOE Project (Details) - Task order to provide deactivation, demolition and removal services at New York State project site - USD ($) $ in Millions	Jan. 31, 2020	Dec. 06, 2019	Mar. 31, 2024	Dec. 31, 2014
Commitments and Contingencies
Percentage of claim recoveries due to purchaser	10%
Percentage of claim recoveries due to seller	90%
Former Affiliate
Commitments and Contingencies
Minimum project cost to pay			$ 146
Department of Energy
Commitments and Contingencies
Maximum project cost to pay			106
Additional fees on changed work scope		$ 60.4		$ 103
Former Affiliate and DOE
Commitments and Contingencies
Maximum project cost to pay			146
Minimum project cost to pay			$ 106
Former Affiliate | Department of Energy | Minimum
Commitments and Contingencies
Damages sought		148.5
Former Affiliate | Department of Energy | Maximum
Commitments and Contingencies
Damages sought		$ 329.4

Commitments and Contingencies_3

Commitments and Contingencies - Refinery Turnaround Project (Details) - Refinery Turnaround Project - USD ($) $ in Millions	1 Months Ended
	Dec. 31, 2019	Apr. 30, 2019	Mar. 31, 2019	Mar. 31, 2024
Commitments and Contingencies
Amount of work outside original contract				$ 90
Payment entitled to				$ 144
Construction lien against the refinery for unpaid labor and materials costs		$ 132
A Refinery in Montana
Commitments and Contingencies
Damages sought, counter party	$ 93		$ 79

Reportable Segments - Summarize

Reportable Segments - Summarized financial information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2024 USD ($) segment	Mar. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)
Summarized financial information concerning the Company's reportable segments
Revenue	$ 3,943,833	$ 3,490,172	$ 7,843,753	$ 6,872,527
Gross profit	261,174	228,094	$ 505,144	443,082
Number of reportable segments | segment			3
Equity in earnings of joint ventures	19,459	7,456	$ (9,482)	17,285
General and administrative expenses	(44,686)	(34,147)	(80,410)	(69,759)
Restructuring costs	(35,465)	(3,973)	(51,645)	(41,432)
Operating income (loss)	200,482	197,430	363,607	349,176
Segment assets	11,457,393		11,457,393		$ 11,233,398
Total
Summarized financial information concerning the Company's reportable segments
Revenue	3,943,900	3,490,100	7,843,800	6,872,500
Gross profit	261,100	228,100	505,100	443,100
Equity in earnings of joint ventures	19,500	7,500	(9,500)	17,300
General and administrative expenses	(44,700)	(34,200)	(80,400)	(69,800)
Restructuring costs	(35,400)	(3,900)	(51,600)	(41,400)
Operating income (loss)	$ 200,500	$ 197,500	$ 363,600	$ 349,200
Gross profit as a % of revenue	6.60%	6.50%	6.40%	6.40%
Operating Segments | Americas
Summarized financial information concerning the Company's reportable segments
Revenue	$ 3,038,600	$ 2,630,200	$ 6,077,300	$ 5,209,500
Gross profit	184,400	173,300	355,400	336,200
Equity in earnings of joint ventures	4,800	4,900	8,400	5,800
Operating income (loss)	$ 189,200	$ 178,200	$ 363,800	$ 342,000
Gross profit as a % of revenue	6.10%	6.60%	5.80%	6.50%
Segment assets	$ 7,754,400		$ 7,754,400		7,433,100
Operating Segments | International
Summarized financial information concerning the Company's reportable segments
Revenue	904,800	$ 859,800	1,765,800	$ 1,662,600
Gross profit	76,200	54,700	149,000	106,500
Equity in earnings of joint ventures	5,000	5,400	9,300	8,700
Operating income (loss)	$ 81,200	$ 60,100	$ 158,300	$ 115,200
Gross profit as a % of revenue	8.40%	6.40%	8.40%	6.40%
Segment assets	$ 2,671,400		$ 2,671,400		2,536,200
Operating Segments | AECOM Capital
Summarized financial information concerning the Company's reportable segments
Revenue	500	$ 100	700	$ 400
Gross profit	500	100	700	400
Equity in earnings of joint ventures	9,700	(2,800)	(27,200)	2,800
General and administrative expenses	(9,700)	(2,900)	(12,100)	(5,600)
Operating income (loss)	500	(5,600)	(38,600)	(2,400)
Segment assets	53,200		53,200		64,500
Corporate
Summarized financial information concerning the Company's reportable segments
General and administrative expenses	(35,000)	(31,300)	(68,300)	(64,200)
Restructuring costs	(35,400)	(3,900)	(51,600)	(41,400)
Operating income (loss)	(70,400)	$ (35,200)	(119,900)	$ (105,600)
Segment assets	$ 873,300		$ 873,300		$ 1,104,400

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 1,007	$ 76,615	$ 95,445	$ 164,560

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 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