AECOM (ACM) 10-Q 11 Aug 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Jun. 30, 2021	Aug. 05, 2021
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
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	300 South Grand Avenue, Suite 900
Entity Address, City or Town	Los Angeles
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	90071
City Area Code	213
Local Phone Number	593-8100
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
Title of 12(b) Security	Common Stock
Trading Symbol	ACM
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		144,061,817
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Central Index Key	0000868857

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 935,434	$ 1,599,688
Cash in consolidated joint ventures	113,596	108,644
Total cash and cash equivalents	1,049,030	1,708,332
Accounts receivable-net	2,669,113	2,920,730
Contract assets	1,498,550	1,611,525
Prepaid expenses and other current assets	867,154	691,707
Current assets held for sale	127,017	562,435
Income taxes receivable	37,629	35,637
TOTAL CURRENT ASSETS	6,248,493	7,530,366
PROPERTY AND EQUIPMENT-NET	410,864	381,672
DEFERRED TAX ASSETS-NET	444,647	361,675
INVESTMENTS IN UNCONSOLIDATED JOINT VENTURES	331,994	297,595
GOODWILL	3,516,781	3,484,221
INTANGIBLE ASSETS-NET	61,666	76,917
OTHER NON-CURRENT ASSETS	311,333	160,036
OPERATING LEASE RIGHT-OF-USE ASSETS	637,313	652,115
NON-CURRENT ASSETS HELD FOR SALE		54,354
TOTAL ASSETS	11,963,091	12,998,951
CURRENT LIABILITIES:
Short-term debt	2,876	223
Accounts payable	2,068,440	2,358,228
Accrued expenses and other current liabilities	2,335,077	2,249,704
Income taxes payable	50,118	47,103
Contract liabilities	1,080,271	996,922
Current liabilities held for sale	90,891	417,623
Current portion of long-term debt	52,358	20,651
TOTAL CURRENT LIABILITIES	5,680,031	6,090,454
OTHER LONG-TERM LIABILITIES	143,286	162,784
OPERATING LEASE LIABILITIES, NON-CURRENT	711,494	745,287
LONG-TERM LIABILITIES HELD FOR SALE	12,260	79,254
DEFERRED TAX LIABILITY-NET	6,157	3,491
PENSION BENEFIT OBLIGATIONS	439,073	463,001
LONG-TERM DEBT	2,153,812	2,041,136
TOTAL LIABILITIES	9,146,113	9,585,407
COMMITMENTS AND CONTINGENCIES (Note 15)
AECOM STOCKHOLDERS' EQUITY:
Common stock-authorized, 300,000,000 shares of $0.01 par value as of June 30, 2021 and September 30, 2020; issued and outstanding 144,877,676 and 157,044,687 shares as of June 30, 2021 and September 30, 2020, respectively	1,449	1,570
Additional paid-in capital	4,100,482	4,035,414
Accumulated other comprehensive loss	(910,532)	(918,674)
(Accumulated deficits) Retained earnings	(483,362)	174,248
TOTAL AECOM STOCKHOLDERS' EQUITY	2,708,037	3,292,558
Noncontrolling interests	108,941	120,986
TOTAL STOCKHOLDERS' EQUITY	2,816,978	3,413,544
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 11,963,091	$ 12,998,951

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2021	Sep. 30, 2020
Consolidated Balance Sheets
Common stock, authorized shares	300,000,000	300,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, issued shares	144,877,676	157,044,687
Common stock, outstanding shares	144,877,676	157,044,687

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Consolidated Statements of Operations
Revenue	$ 3,408,357	$ 3,189,679	$ 9,987,085	$ 9,671,026
Cost of revenue	3,206,823	3,004,600	9,405,922	9,151,334
Gross profit	201,534	185,079	581,163	519,692
Equity in earnings of joint ventures	8,270	8,573	23,628	32,006
General and administrative expenses	(36,340)	(54,482)	(110,707)	(139,133)
Restructuring costs	(12,971)	(20,300)	(34,755)	(96,438)
Income from operations	160,493	118,870	459,329	316,127
Other income	4,482	3,119	11,812	9,557
Interest expense	(149,038)	(34,925)	(212,489)	(112,413)
Income from continuing operations before taxes	15,937	87,064	258,652	213,271
Income tax (benefit) expense for continuing operations	(17,938)	(7,184)	42,811	30,326
Net income from continuing operations	33,875	94,248	215,841	182,945
Net loss from discontinued operations	(15,502)	(126)	(119,168)	(112,695)
Net income	18,373	94,122	96,673	70,250
Net income attributable to noncontrolling interests from continuing operations	(5,901)	(3,138)	(16,160)	(12,428)
Net income attributable to noncontrolling interests from discontinued operations	(941)	(1,645)	(3,495)	(14,005)
Net income attributable to noncontrolling interests	(6,842)	(4,783)	(19,655)	(26,433)
Net income attributable to AECOM from continuing operations	27,974	91,110	199,681	170,517
Net loss attributable to AECOM from discontinued operations	(16,443)	(1,771)	(122,663)	(126,700)
Net income attributable to AECOM	$ 11,531	$ 89,339	$ 77,018	$ 43,817
Net income (loss) attributable to AECOM per share:
Basic continuing operations per share	$ 0.19	$ 0.57	$ 1.35	$ 1.07
Basic discontinued operations per share	(0.11)	(0.01)	(0.83)	(0.79)
Basic earnings per share	0.08	0.56	0.52	0.28
Diluted continuing operations per share	0.19	0.56	1.32	1.06
Diluted discontinued operations per share	(0.11)	(0.01)	(0.81)	(0.79)
Diluted earnings per share	$ 0.08	$ 0.55	$ 0.51	$ 0.27
Weighted average shares outstanding:
Basic	146,109	160,119	148,434	158,667
Diluted	148,859	161,835	150,707	161,070

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Consolidated Statements of Comprehensive (Loss) Income
Net income	$ 18,373	$ 94,122	$ 96,673	$ 70,250
Other comprehensive (loss) income, net of tax:
Net unrealized gain on derivatives, net of tax	830	(18)	2,783	3,157
Foreign currency translation adjustments	(18,775)	71,595	13,111	28,113
Pension adjustments, net of tax	3,220	4,617	(7,491)	27,329
Other comprehensive (loss) income, net of tax	(14,725)	76,194	8,403	58,599
Comprehensive income, net of tax	3,648	170,316	105,076	128,849
Noncontrolling interests in comprehensive income of consolidated subsidiaries, net of tax	(6,913)	(5,016)	(19,916)	(26,448)
Comprehensive (loss) income attributable to AECOM, net of tax	$ (3,265)	$ 165,300	$ 85,160	$ 102,401

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Retained Earnings (Deficits)Cumulative effect of accounting standard adoption	Retained Earnings (Deficits)	Total AECOM Stockholders' EquityCumulative effect of accounting standard adoption	Total AECOM Stockholders' Equity	Non-Controlling Interests	Cumulative effect of accounting standard adoption	Total
BALANCE at Sep. 30, 2019	$ 1,575	$ 3,953,650	$ (864,197)		$ 599,548		$ 3,690,576	$ 208,774		$ 3,899,350
Increase (Decrease) in Stockholders' Equity
Net income					43,817		43,817	26,433		70,250
Other comprehensive loss			58,584				58,584	15		58,599
Issuance of stock	40	53,106					53,146			53,146
Repurchases of stock	(13)	(35,591)			(14,875)		(50,479)			(50,479)
Stock based compensation		37,037					37,037			37,037
Disposal of noncontrolling interest of business sold								(60,089)		(60,089)
Other transactions with noncontrolling interests								4,361		4,361
Contributions from noncontrolling interests								8,289		8,289
Distributions to noncontrolling interests								(46,808)		(46,808)
BALANCE at Jun. 30, 2020	1,602	4,008,202	(805,613)		540,703		3,744,894	140,975		3,885,869
BALANCE at Mar. 31, 2020	1,589	3,960,123	(881,574)		451,364		3,531,502	134,021		3,665,523
Increase (Decrease) in Stockholders' Equity
Net income					89,339		89,339	4,783		94,122
Other comprehensive loss			75,961				75,961	233		76,194
Issuance of stock	13	37,859					37,872			37,872
Repurchases of stock		(280)					(280)			(280)
Stock based compensation		(10,500)					(10,500)			(10,500)
Other transactions with noncontrolling interests								3,545		3,545
Contributions from noncontrolling interests								2,108		2,108
Distributions to noncontrolling interests								(3,715)		(3,715)
BALANCE at Jun. 30, 2020	1,602	4,008,202	(805,613)		540,703		3,744,894	140,975		3,885,869
Increase (Decrease) in Stockholders' Equity
Retained Earnings (Accumulated Deficit)				$ (87,787)		$ (87,787)			$ (87,787)
Retained Earnings (Accumulated Deficit)										174,248
BALANCE at Sep. 30, 2020	1,570	4,035,414	(918,674)		174,248		3,292,558	120,986		3,413,544
Increase (Decrease) in Stockholders' Equity
Net income					77,018		77,018	19,655		96,673
Other comprehensive loss			8,142				8,142	261		8,403
Issuance of stock	24	51,908					51,932			51,932
Repurchases of stock	(145)	(23,053)			(726,649)		(749,847)			(749,847)
Stock based compensation		36,213					36,213			36,213
Disposal of noncontrolling interest of business sold								(24,039)		(24,039)
Other transactions with noncontrolling interests								580		580
Contributions from noncontrolling interests								226		226
Distributions to noncontrolling interests								(8,728)		(8,728)
BALANCE at Jun. 30, 2021	1,449	4,100,482	(910,532)		(483,362)		2,708,037	108,941		2,816,978
BALANCE at Mar. 31, 2021	1,468	4,054,089	(895,736)		(336,852)		2,822,969	103,731		2,926,700
Increase (Decrease) in Stockholders' Equity
Net income					11,531		11,531	6,842		18,373
Other comprehensive loss			(14,796)				(14,796)	71		(14,725)
Issuance of stock	5	34,913					34,918			34,918
Repurchases of stock	(24)	(111)			(158,041)		(158,176)			(158,176)
Stock based compensation		11,591					11,591			11,591
Distributions to noncontrolling interests								(1,703)		(1,703)
BALANCE at Jun. 30, 2021	$ 1,449	$ 4,100,482	$ (910,532)		$ (483,362)		$ 2,708,037	$ 108,941		2,816,978
Increase (Decrease) in Stockholders' Equity
Retained Earnings (Accumulated Deficit)				$ (7,979)		$ (7,979)			$ (7,979)	$ (483,362)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 96,673	$ 70,250
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	129,288	181,440
Equity in earnings of unconsolidated joint ventures	(28,294)	(4,084)
Distribution of earnings from unconsolidated joint ventures	26,554	47,675
Non-cash stock compensation	36,213	37,037
Prepayment premium on redemption of unsecured notes	117,500
Impairment of long-lived assets	105,194	89,288
Loss (gain) on sale of discontinued operations	56,222	(161,900)
Foreign currency translation	(33,318)	40,618
Other	11,162	14,265
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable and contract assets	373,248	(315,983)
Prepaid expenses and other assets	(290,039)	(51,033)
Accounts payable	(271,947)	(385,479)
Accrued expenses and other current liabilities	58,901	(4,427)
Contract liabilities	134,815	82,212
Other long-term liabilities	(135,584)	40,391
Net cash provided by (used in) operating activities	386,588	(319,730)
CASH FLOWS FROM INVESTING ACTIVITIES:
(Payment for) proceeds from sale of discontinued operations, net of cash disposed	(265,876)	2,218,866
Investment in unconsolidated joint ventures	(51,852)	(89,283)
Return of investment in unconsolidated joint ventures	2,868	17,042
Proceeds from sale of investments	15,507	8,277
Proceeds from disposal of property and equipment	10,284	2,510
Payments for capital expenditures	(112,603)	(83,266)
Net cash (used in) provided by investing activities	(401,672)	2,074,146
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from borrowings under credit agreements	2,848,244	4,203,556
Repayments of borrowings under credit agreements	(1,929,251)	(5,547,055)
Redemption of unsecured senior notes	(797,252)
Prepayment premium on redemption of unsecured senior notes	(117,500)
Cash paid for debt issuance costs	(10,284)	(3,179)
Proceeds from issuance of common stock	19,347	17,231
Proceeds from exercise of stock options	4,038
Payments to repurchase common stock	(749,847)	(50,479)
Net distributions to noncontrolling interests	(8,502)	(38,519)
Other financing activities	(13,882)	12,909
Net cash used in financing activities	(754,889)	(1,405,536)
EFFECT OF EXCHANGE RATE CHANGES ON CASH	6,591	(4,885)
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(763,382)	343,995
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	1,818,249	1,080,354
CASH AND CASH EQUIVALENTS AT END OF PERIOD	1,054,867	1,424,349
LESS CASH AND CASH EQUIVALENTS INCLUDED IN CURRENT ASSETS HELD FOR SALE	(5,837)	(93,081)
CASH AND CASH EQUIVALENTS OF CONTINUING OPERATIONS AT END OF PERIOD	$ 1,049,030	$ 1,331,268

Basis of Presentation

Basis of Presentation	9 Months Ended
	Jun. 30, 2021
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, 2020 (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. Certain reclassifications were made to the prior year to conform to current year presentation. ​ The results of operations for the three and nine months ended June 30, 2021 are not necessarily indicative of the results to be expected for the fiscal year ending September 30, 2021. ​ On January 31, 2020, the Company completed the sale of its Management Services business to an affiliate of American Securities LLC and Lindsay Goldberg LLC. Additionally, 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 year 2020. Collectively, the Management Services business and the self-perform at-risk construction businesses met the criteria for discontinued operation classification. As a result, the Management Services business and 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	9 Months Ended
	Jun. 30, 2021
New Accounting Pronouncements and Changes in Accounting
New Accounting Pronouncements and Changes in Accounting	2. New Accounting Pronouncements and Changes in Accounting ​ In February 2016, the Financial Accounting Standards Board (FASB) issued new accounting guidance which changes accounting requirements for leases. The new guidance requires lessees to recognize the assets and liabilities arising from all leases, including those classified as operating leases under previous accounting guidance, on the balance sheet. It also requires disclosure of key information about leasing arrangements to increase transparency and comparability among organizations. The Company adopted the new guidance beginning October 1, 2019 using the modified retrospective adoption method, which resulted in a downward adjustment to retained earnings of $87.8 million, net of tax. Detailed disclosures regarding the adoption and other required disclosures can be found in Note 12. ​ In June 2016, the FASB issued a new credit loss standard that changes the impairment model for most financial assets and some other instruments. The new guidance replaces the “incurred loss” approach with an “expected loss” model for instruments measured at amortized cost. It also simplifies the accounting model for purchased credit-impaired debt securities and loans. The Company adopted the new guidance effective October 1, 2020 using a modified retrospective approach that resulted in an $8.0 million, net of tax, reduction to retained earnings without restating comparative periods. Additional disclosures regarding the adoption can be found in Note 4. ​ In February 2018, the FASB issued new accounting guidance which provides entities the option to reclassify certain tax effects from other comprehensive income to retained earnings. The guidance addresses a narrow-scope financial reporting issue related to the tax effects that may become stranded in accumulated other comprehensive income as a result of the enactment of the Tax Cuts and Jobs Act (Tax Act). Under the guidance, an entity may elect to reclassify the income tax effects of the Tax Act on items within accumulated other comprehensive income to retained earnings. The Company has determined that it will not make this election. ​ In August 2018, the FASB issued new accounting guidance aligning the capitalization of certain implementation costs incurred in a hosting arrangement that is a service contract with previously existing guidance for capitalizing costs incurred to develop internal-use software. The new guidance was effective for the Company’s fiscal year starting October 1, 2020. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements. ​ In August 2018, the FASB issued new accounting guidance amending the disclosure requirements for fair value measurements. These improvements require more disclosure for amounts measured at fair value, and specifically unobservable inputs used in fair value measurements. The Company adopted the new guidance starting on October 1, 2020. Adoption of the new guidance did not have a significant impact on the Company’s financial reporting process. ​ In August 2018, the FASB issued new accounting guidance for the disclosure requirements of defined benefit pension plans. The amended guidance eliminates certain disclosure requirements that were no longer considered to be cost beneficial. The Company expects to adopt the new guidance starting on October 1, 2021 and does not expect adoption of the new guidance will have a significant impact on its financial reporting process. ​ In March 2020, the Securities and Exchange Commission (SEC) adopted final rules that amend the financial disclosure requirement for guarantors of registered debt securities in Rule 3-10 of Regulation S-X. The new rules amend and streamline the disclosures required by guarantors and issuers of guaranteed securities. Among other things, the new disclosures may be located outside the financial statements. The new rule was effective January 4, 2021, and early adoption is permitted. The Company adopted the new rule on March 31, 2020. Accordingly, the revised condensed consolidating financial information is presented outside of these consolidated financial statements. ​

Discontinued Operations, Goodwi

Discontinued Operations, Goodwill, and Intangible Assets	9 Months Ended
	Jun. 30, 2021
Discontinued Operations, Goodwill and Intangible Assets
Discontinued Operations, Goodwill, and Intangible Assets	3. Discontinued Operations, Goodwill and Intangible Assets ​ During the second quarter of fiscal 2020, the Company completed the sale of its Management Services business to Maverick Purchaser Sub, LLC (Purchaser), an affiliate of American Securities LLC and Lindsay Goldberg LLC. The Company received total cash consideration of $2.28 billion inclusive of the receipt in the third quarter of fiscal 2020 of $122.0 million received in connection with a favorable working capital purchase price adjustment and contingent consideration of approximately $120 million attributable to certain claims related to prior work and engagements. As a result of the sale, the Company recognized a pre-tax gain of $161.9 million. The gain on sale was included in the net loss from discontinued operations in the Consolidated Statements of Operations. ​ Additionally, in the first quarter of fiscal 2020, management approved a plan to dispose via sale the Company’s self-perform at-risk construction businesses within the next year. 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 Management Services business and 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 will have a major effect on the Company’s operations and financial results and qualified for presentation as discontinued operations in accordance with FASB Accounting Standards Codification (ASC) 205-20. Accordingly, the financial results of the Management Services business and 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 Sheet as assets and liabilities held for sale for both periods presented. Interest expense allocated to discontinued operations represents interest expenses for the discontinued operations’ finance leases and term loans, which were required to be settled upon the sale of the Management Services business. ​ During the first quarter of fiscal 2021, the Company completed the sale of its power construction business to CriticalPoint Capital, LLC. The Company recorded $17.3 million through the first nine months of fiscal 2021 related to payments for post-closing working capital adjustments. ​ The Company also completed the sale of its civil infrastructure construction business to affiliates of Oroco Capital in the second quarter of fiscal 2021. During the second quarter of fiscal 2021, the Company recorded a $32.8 million loss related to the sale of its civil infrastructure construction businesses. Under the terms of the sale agreement, the Company made the required cash payments and delivered the cash and cash equivalents, including cash in consolidated joint ventures, on the balance sheet at closing. As a result, the Company recorded the net cash movement of the sale as a use of cash in the investing section of its statement of cash flows. ​ The following table represents summarized balance sheet information of assets and liabilities held for sale (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ September 30, ​ 2021 2020 ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 5.8 ​ $ 109.9 Receivables and contract assets ​ 70.9 ​ 414.3 Other ​ 50.3 ​ 38.2 Current assets held for sale ​ $ 127.0 ​ $ 562.4 ​ ​ ​ ​ ​ ​ ​ Property and equipment, net ​ $ 52.4 ​ $ 119.8 Other ​ 19.0 ​ 181.8 Write-down of assets to fair value less cost to sell ​ ​ (71.4) ​ ​ (247.2) Non-current assets held for sale ​ $ — ​ $ 54.4 ​ ​ ​ ​ ​ ​ ​ Accounts payable and accrued expenses ​ $ 76.9 ​ $ 350.4 Contract liabilities ​ 9.2 ​ 65.6 Other ​ 4.8 ​ 1.6 Current liabilities held for sale ​ $ 90.9 ​ $ 417.6 ​ ​ ​ ​ ​ ​ ​ Long-term liabilities held for sale ​ $ 12.3 ​ $ 79.3 ​ The following table represents summarized income statement information of discontinued operations (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended Nine months ended ​ ​ June 30, ​ June 30, June 30, ​ June 30, ​ 2021 2020 2021 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 162.9 ​ $ 347.5 ​ $ 606.6 ​ $ 2,661.8 Cost of revenue ​ 159.6 ​ 352.5 ​ ​ 600.4 ​ ​ 2,708.5 Gross profit (loss) ​ 3.3 ​ (5.0) ​ ​ 6.2 ​ ​ (46.7) Equity in earnings (losses) of joint ventures ​ (3.4) ​ (11.1) ​ ​ 4.6 ​ ​ (28.0) (Loss) gain on disposal activities ​ ​ (6.1) ​ ​ 14.9 ​ ​ (56.2) ​ ​ 161.9 Transaction costs ​ ​ (0.7) ​ ​ — ​ ​ (14.3) ​ ​ (41.4) Impairment of long-lived assets ​ ​ (9.4) ​ ​ — ​ ​ (105.2) ​ ​ (89.3) Loss from operations ​ (16.3) ​ (1.2) ​ ​ (164.9) ​ ​ (43.5) Other (expense) income ​ — ​ (0.2) ​ ​ — ​ ​ 1.6 Interest expense ​ (0.1) ​ (1.5) ​ ​ (0.4) ​ ​ (40.2) Loss before taxes ​ (16.4) ​ (2.9) ​ ​ (165.3) ​ ​ (82.1) Income tax (benefit) expense ​ (0.9) ​ (2.8) ​ ​ (46.1) ​ ​ 30.6 Net loss from discontinued operations ​ $ (15.5) ​ $ (0.1) ​ $ (119.2) ​ $ (112.7) ​ The significant components included in the Consolidated Statement of Cash Flows for the discontinued operations are as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended Nine months ended ​ ​ June 30, June 30, ​ June 30, June 30, ​ 2021 ​ 2020 2021 ​ 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization: ​ ​ ​ ​ ​ ​ ​ ​ Property and equipment ​ $ — ​ $ — ​ $ — ​ $ 4.6 Intangible assets and capitalized debt issuance costs ​ $ — ​ $ 4.3 ​ $ — ​ $ 35.8 Payments for capital expenditures ​ $ (2.0) ​ $ (2.6) ​ $ (6.6) ​ $ (16.8) ​ The changes in the carrying value of goodwill by reportable segment for the nine months ended June 30, 2021 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ ​ September 30, ​ Exchange ​ June 30, ​ 2020 Impact 2021 ​ ​ (in millions) Americas ​ $ 2,617.1 ​ $ 14.2 ​ $ 2,631.3 International ​ 867.1 ​ 18.4 ​ 885.5 Total ​ $ 3,484.2 ​ $ 32.6 ​ $ 3,516.8 ​ The gross amounts and accumulated amortization of the Company’s acquired identifiable intangible assets with finite useful lives as of June 30, 2021 and September 30, 2020, included in intangible assets—net, in the accompanying consolidated balance sheets, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2021 ​ September 30, 2020 ​ ​ ​ ​ Gross ​ Accumulated ​ Intangible ​ Gross ​ Accumulated ​ Intangible ​ Amortization ​ Amount Amortization Assets, Net Amount Amortization Assets, Net Period ​ ​ (in millions) ​ (years) Backlog and customer relationships ​ $ 663.5 ​ $ (601.8) ​ $ 61.7 ​ $ 662.8 ​ $ (585.9) ​ $ 76.9 1 - 11 ​ Amortization expense of acquired intangible assets included within cost of revenue was $15.9 million and $18.3 million for the nine months ended June 30, 2021 and 2020, respectively. The following table presents estimated amortization expense of existing intangible assets for the remainder of fiscal 2021 and for the succeeding years: ​ ​ ​ ​ ​ Fiscal Year (in millions) 2021 (three months remaining) ​ $ 4.9 2022 ​ 19.8 2023 ​ 18.8 2024 ​ 17.4 2025 ​ ​ 0.8 Total ​ $ 61.7 ​

Revenue Recognition

Revenue Recognition	9 Months Ended
	Jun. 30, 2021
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. 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 costs included in revenues for the nine months ended June 30, 2021 and 2020 were $5.4 billion and $5.1 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. ​ The following tables present the Company’s revenues disaggregated by revenue sources: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ June 30, ​ June 30, ​ June 30, ​ June 30, ​ 2021 2020 2021 2020 ​ (in millions) Cost reimbursable ​ $ 1,309.2 ​ $ 1,369.3 ​ $ 4,041.8 ​ $ 4,252.5 Guaranteed maximum price ​ 1,229.9 ​ ​ 829.8 ​ ​ 3,443.0 ​ ​ 2,706.4 Fixed price ​ 869.3 ​ ​ 990.6 ​ ​ 2,502.3 ​ ​ 2,712.1 Total revenue ​ $ 3,408.4 ​ $ 3,189.7 ​ $ 9,987.1 ​ $ 9,671.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ June 30, ​ June 30, ​ June 30, ​ June 30, ​ 2021 2020 2021 2020 ​ (in millions) Americas ​ $ 2,619.0 ​ $ 2,471.8 ​ $ 7,645.7 ​ $ 7,400.5 Europe, Middle East, Africa ​ 401.3 ​ ​ 359.9 ​ ​ 1,201.8 ​ ​ 1,194.9 Asia Pacific ​ 388.1 ​ ​ 358.0 ​ ​ 1,139.6 ​ ​ 1,075.6 Total revenue ​ $ 3,408.4 ​ $ 3,189.7 ​ $ 9,987.1 ​ $ 9,671.0 ​ As of June 30, 2021, the Company had allocated $18.5 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 . ​ Contract liabilities represent amounts billed to clients in excess of revenue recognized to date. The Company recognized revenue of $646.6 million and $563.1 million during the nine months ended June 30, 2021 and 2020, respectively, that was included in contract liabilities as of September 30, 2020 and 2019, 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ September 30, ​ ​ 2021 2020 ​ ​ (in millions) Billed ​ $ 2,225.0 ​ $ 2,467.3 Contract retentions ​ 541.6 ​ ​ 531.3 Total accounts receivable—gross ​ 2,766.6 ​ ​ 2,998.6 Allowances for doubtful accounts and credit losses ​ (97.5) ​ ​ (77.9) Total accounts receivable—net ​ $ 2,669.1 ​ $ 2,920.7 ​ Substantially all contract assets as of June 30, 2021 and September 30, 2020 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 as of both June 30, 2021 and September 30, 2020. The asset related to the Deactivation, Demolition, and Removal Project retained from the Purchaser 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. These retention agreements vary from project to project and could be outstanding for several months or years. ​ On October 1, 2020, the Company adopted accounting pronouncements issued by the FASB regarding the changes to the way in which entities estimate credit losses for most financial assets, including accounts receivable and contract assets. The new guidance requires the Company to maintain an allowance for credit losses, which represent the portion of its financial assets that it does not expect to collect over their contractual life. 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 June 30, 2021 and September 30, 2020. ​ The Company sold trade receivables to financial institutions, of which $243.7 million and $166.6 million were outstanding as of June 30, 2021 and September 30, 2020, 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	9 Months Ended
	Jun. 30, 2021
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, operations and maintenance services, and invest 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ ​ ​ ​ ​ 2021 ​ September 30, ​ ​ (unaudited) 2020 ​ ​ (in millions) Current assets ​ $ 530.2 ​ $ 536.3 Non-current assets ​ 75.3 ​ 77.0 Total assets ​ $ 605.5 ​ $ 613.3 ​ ​ ​ ​ ​ ​ ​ Current liabilities ​ $ 390.2 ​ $ 409.9 Non-current liabilities ​ 1.5 ​ 1.5 Total liabilities ​ 391.7 ​ 411.4 Total AECOM equity ​ 118.1 ​ 113.9 Noncontrolling interests ​ 95.7 ​ 88.0 Total owners’ equity ​ 213.8 ​ 201.9 Total liabilities and owners’ equity ​ $ 605.5 ​ $ 613.3 ​ Total revenue of the consolidated joint ventures was $604.7 million and $602.1 million for the nine months ended June 30, 2021 and 2020, 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, is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ September 30, ​ ​ 2021 2020 ​ ​ (in millions) Current assets ​ $ 1,345.7 ​ $ 1,374.3 Non-current assets ​ 546.2 ​ 465.9 Total assets ​ $ 1,891.9 ​ $ 1,840.2 ​ ​ ​ ​ ​ ​ ​ Current liabilities ​ $ 912.1 ​ $ 953.4 Non-current liabilities ​ 57.2 ​ 58.9 Total liabilities ​ 969.3 ​ 1,012.3 Joint ventures’ equity ​ 922.6 ​ 827.9 Total liabilities and joint ventures’ equity ​ $ 1,891.9 ​ $ 1,840.2 ​ ​ ​ ​ ​ ​ ​ AECOM’s investment in joint ventures ​ $ 332.0 ​ $ 297.6 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ June 30, ​ June 30, ​ 2021 2020 ​ ​ (in millions) Revenue ​ $ 1,588.4 ​ $ 2,325.7 Cost of revenue ​ 1,539.8 ​ 2,281.7 Gross profit ​ $ 48.6 ​ $ 44.0 Net income ​ $ 41.8 ​ $ 42.7 ​ Summary of AECOM’s equity in earnings of unconsolidated joint ventures is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ June 30, June 30, ​ 2021 2020 ​ (in millions) Pass through joint ventures ​ $ 18.8 ​ $ 26.0 Other joint ventures ​ 4.8 ​ ​ 6.0 Total ​ $ 23.6 ​ $ 32.0 ​

Pension Benefit Obligations

Pension Benefit Obligations	9 Months Ended
	Jun. 30, 2021
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 nine months ended June 30, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ June 30,2021 ​ June 30,2020 ​ June 30,2021 ​ June 30,2020 ​ 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 ​ $ — ​ $ 0.4 ​ $ — ​ $ 0.4 Interest cost on projected benefit obligation ​ 1.1 ​ ​ 5.5 ​ ​ 1.6 ​ ​ 5.4 ​ 3.2 ​ ​ 16.2 ​ ​ 4.8 ​ ​ 16.7 Expected return on plan assets ​ (1.6) ​ ​ (11.1) ​ ​ (1.8) ​ ​ (9.1) ​ (4.8) ​ ​ (32.6) ​ ​ (5.3) ​ ​ (27.9) Amortization of prior service cost ​ ​ — ​ ​ 0.1 ​ ​ — ​ ​ — ​ ​ — ​ ​ 0.1 ​ ​ 0.1 ​ ​ — Amortization of net loss ​ 1.4 ​ ​ 2.4 ​ ​ 1.3 ​ ​ 2.1 ​ 4.4 ​ ​ 6.9 ​ ​ 3.7 ​ ​ 6.4 Curtailment loss recognized ​ ​ — ​ ​ — ​ ​ 0.5 ​ ​ — ​ ​ — ​ ​ — ​ ​ 0.5 ​ ​ — Settlement loss recognized ​ ​ 0.1 ​ ​ — ​ ​ — ​ ​ — ​ ​ 0.1 ​ ​ — ​ ​ 0.5 ​ ​ 0.2 Net periodic benefit cost ​ $ 1.0 ​ $ (3.0) ​ $ 1.6 ​ $ (1.5) ​ $ 2.9 ​ $ (9.0) ​ $ 4.3 ​ $ (4.2) ​ The total amounts of employer contributions paid for the nine months ended June 30, 2021 were $10.1 million for U.S. plans and $18.9 million for non-U.S. plans. The expected remaining scheduled annual employer contributions for the fiscal year ending September 30, 2021 are $4.6 million for U.S. plans and $7.8 million for non-U.S. plans.

Debt

Debt	9 Months Ended
	Jun. 30, 2021
Debt
Debt	7. Debt ​ Debt consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ September 30, ​ 2021 2020 ​ ​ (in millions) Credit Agreement ​ $ 1,156.9 ​ $ 248.5 2024 Senior Notes ​ ​ — ​ ​ 797.3 2027 Senior Notes ​ ​ 997.3 ​ ​ 997.3 Other debt ​ 79.7 ​ 41.9 Total debt ​ 2,233.9 ​ 2,085.0 Less: Current portion of debt and short-term borrowings ​ (55.2) ​ (20.9) Less: Unamortized debt issuance costs ​ ​ (24.9) ​ ​ (23.0) Long-term debt ​ $ 2,153.8 ​ $ 2,041.1 ​ The following table presents, in millions, scheduled maturities of the Company’s debt as of June 30, 2021: ​ ​ ​ ​ ​ Fiscal Year ​ ​ 2021 (three months remaining) ​ $ 14.9 2022 ​ 48.2 2023 ​ 38.1 2024 ​ 39.4 2025 ​ 34.2 Thereafter ​ 2,059.1 Total ​ $ 2,233.9 ​ Credit Agreement ​ The Company entered into a credit agreement (Credit Agreement) on October 17, 2014, which, as amended to date, consists of (i) a term loan A facility that included a $510 million (US) term loan A facility with a term that expired on March 13, 2021 and a $500 million Canadian dollar (CAD) term loan A facility and a $250 million Australian dollar (AUD) term loan A facility, each with terms expiring on March 13, 2023; (ii) a $600 million term loan B facility with a term expiring on March 13, 2025; and (iii) a revolving credit facility in an aggregate principal amount of $1.35 billion with a term expiring on March 13, 2023. Some subsidiaries of the Company (Guarantors) have guaranteed the obligations of the borrowers under the Credit Agreement. The borrowers’ obligations under the Credit Agreement are secured by a lien on substantially all of the assets of the Company and the Guarantors pursuant to a security and pledge agreement (Security Agreement). The collateral under the Security Agreement is subject to release upon fulfillment of conditions specified in the Credit Agreement and Security Agreement. ​ The Credit Agreement contains covenants that limit the ability of the Company and the ability of some of its subsidiaries to, among other things: (i) create, incur, assume, or suffer to exist liens; (ii) incur or guarantee indebtedness; (iii) pay dividends or repurchase stock; (iv) enter into transactions with affiliates; (v) consummate asset sales, acquisitions or mergers; (vi) enter into various types of burdensome agreements; or (vii) make investments. ​ On July 1, 2015, the Credit Agreement was amended to revise the definition of “Consolidated EBITDA” to increase the allowance for acquisition and integration expenses related to the Company’s acquisition of the URS Corporation (URS) in October 2014. ​ On December 22, 2015, the Credit Agreement was amended to further revise the definition of “Consolidated EBITDA” by further increasing the allowance for acquisition and integration expenses related to the acquisition of URS and to allow for an internal corporate restructuring primarily involving the Company’s international subsidiaries. ​ On September 29, 2016, the Credit Agreement and the Security Agreement were amended to (1) lower the applicable interest rate margins for the term loan A and the revolving credit facilities, and lower the applicable letter of credit fees and commitment fees to the revised consolidated leverage levels; (2) extend the term of the term loan A and the revolving credit facility to September 29, 2021; (3) add a new delayed draw term loan A facility tranche in the amount of $185.0 million; (4) replace the then existing $500 million performance letter of credit facility with a $500 million basket to enter into secured letters of credit outside the Credit Agreement; and (5) revise covenants, including the Maximum Consolidated Leverage Ratio so that the step down from a 5.00 to a 4.75 leverage ratio is effective as of March 31, 2017 as well as the investment basket for the Company’s AECOM Capital business. ​ On March 31, 2017, the Credit Agreement was amended to (1) expand the ability of restricted subsidiaries to borrow under “Incremental Term Loans;” (2) revise the definition of “Working Capital” as used in “Excess Cash Flow;” (3) revise the definitions for “Consolidated EBITDA” and “Consolidated Funded Indebtedness” to reflect the expected gain and debt repayment of an AECOM Capital disposition, which disposition was completed on April 28, 2017; and (4) amend provisions relating to the Company’s ability to undertake internal restructuring steps to accommodate changes in tax laws. ​ On March 13, 2018, the Credit Agreement was amended to (1) refinance the existing term loan A facility to include a $510 million (US) term loan A facility with a term expiring on March 13, 2021 and a $500 million CAD term loan A facility and a $250 million AUD term loan A facility each with terms expiring on March 13, 2023; (2) issue a new $600 million term loan B facility to institutional investors with a term expiring on March 13, 2025; (3) increase the capacity of the Company’s revolving credit facility from $1.05 billion to $1.35 billion and extend its term until March 13, 2023; (4) reduce the Company’s interest rate borrowing costs as follows: (a) the term loan B facility, at the Company’s election, Base Rate (as defined in the Credit Agreement) plus 0.75% or Eurocurrency Rate (as defined in the Credit Agreement) plus 1.75%, (b) the (US) term loan A facility, at the Company’s election, Base Rate plus 0.50% or Eurocurrency Rate plus 1.50%, and (c) the Canadian (CAD) term loan A facility, the Australian (AUD) term loan A facility, and the revolving credit facility, an initial rate of, at the Company’s election, Base Rate plus 0.75% or Eurocurrency Rate plus 1.75%, and after the end of the Company’s fiscal quarter ended June 30, 2018, Base Rate loans plus a margin ranging from 0.25% to 1.00% or Eurocurrency Rate plus a margin from 1.25% to 2.00%, based on the Consolidated Leverage Ratio (as defined in the Credit Agreement); (5) revise covenants including increasing the amounts available under the restricted payment negative covenant and revising the Maximum Consolidated Leverage Ratio (as defined in the Credit Agreement) to include a 4.5 leverage ratio through September 30, 2019 after which the leverage ratio stepped down to 4.0. ​ On November 13, 2018, the Credit Agreement was amended to revise the definition of “Consolidated EBITDA” to increase corporate restructuring allowances and provide for additional flexibility under the covenants for non-core asset dispositions, among other changes. ​ On January 28, 2020, AECOM entered into Amendment No. 7 to the Credit Agreement which modifies the asset disposition covenant to permit the sale of our Management Services business and the mandatory prepayment provision so that only outstanding term loans are prepaid using the net proceeds from the sale. ​ On May 1, 2020, the Company entered into Amendment No. 8 to the Credit Agreement which allows for borrowings to be made, until three months after closing, up to an aggregate principal amount of $400,000,000 under a secured delayed draw term loan facility, the proceeds of which are permitted to be used to pay all or a portion of the amounts payable in connection with any tender for or redemption or repayment of the Company’s or its subsidiaries’ existing senior unsecured notes and any associated fees and expenses. The amendment also revised certain terms and covenants in the Credit Agreement, including by, among other things, the maximum leverage ratio covenant to 4.00:1.00, subject to increases to 4.50:1.00 for certain specified periods in connection with certain material acquisitions, increasing the potential size of incremental facilities under the Credit Agreement, revising the definition of “Consolidated EBITDA” to provide for additional flexibility in the calculation thereof and adding a Eurocurrency Rate floor of 0.75% to the interest rate under the revolving credit facility. On July 30, 2020, the Company drew $248.5 million on its secured delayed draw term loan facility (Term A Facility) for the purpose of redeeming all of the 2022 URS Senior Notes. On February 8, 2021, the Company entered into the 2021 Refinancing Amendment to the Credit Agreement, pursuant to which the maturity of the revolving credit facility and the term loans outstanding under the Credit Agreement were extended to February 8, 2026. In addition, the refinancing amendment reduced the size of the revolving credit facility to $1,150,000,000. The applicable interest rate under the Credit Agreement is calculated at a per annum rate equal to, at our option, (a) the Eurocurrency Rate (as defined in the Credit Agreement) plus an applicable margin (the “LIBOR Applicable Margin”), which is currently at 1.50% or (b) the Base Rate (as defined in the Credit Agreement) plus an applicable margin (the “Base Rate Applicable Margin” and together with the LIBOR Applicable Margin, the “Applicable Margins”), which is currently at 0.50%. The Credit Agreement includes certain environmental, social and governance (ESG) metrics relating to our CO 2 ​ On April 13, 2021, the Company entered into Amendment No. 10 to the Credit Agreement, pursuant to which the lenders thereunder provided a secured term “B” credit facility (Term B Facility) to the Company in an aggregate principal amount of $700,000,000. The Term B Facility matures on April 13, 2028. The proceeds of the 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 the Company’s outstanding 5.875% Senior Notes due 2024. ​ The Term B Facility is subject to the same affirmative and negative covenants and events of default as the existing term loans previously incurred pursuant to the existing Credit Agreement (except that the financial covenants in the existing Credit Agreement do not apply to the Term B Facility). The applicable interest rate for the Term B Facility is calculated at a per annum rate equal to, at the Company’s option, (a) the Eurocurrency Rate (as defined in the Credit Agreement) plus 1.75% or (b) the Base Rate (as defined in the Credit Agreement) plus 0.75%. ​ On June 25, 2021, the Company entered into Amendment No. 11 to the Credit Agreement, pursuant to which the lenders have provided to the Company an additional $215,000,000 in aggregate principal amount under the Term A Facility. The Term A Facility matures on February 8, 2026. The Company used the net proceeds from the increase in the 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. ​ The Company is required to maintain a consolidated interest coverage ratio of at least 3.00 to 1.00 and 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 Company’s consolidated leverage ratio was 2.5 at June 30, 2021. The Company’s consolidated interest coverage ratio was 6.8 at June 30, 2021. As of June 30, 2021, the Company was in compliance with the covenants of the Credit Agreement. At June 30, 2021 and September 30, 2020, letters of credit totaled $11.2 million and $19.0 million, respectively, under the Company’s revolving credit facilities. As of June 30, 2021 and September 30, 2020, the Company had $1,138.8 million and $1,331.0 million, respectively, available under its revolving credit facility. ​ 2024 Senior Notes ​ On October 6, 2014, the Company completed a private placement offering of $800,000,000 aggregate principal amount of the unsecured 5.875% Senior Notes due 2024 (the 2024 Notes). On November 2, 2015, the Company completed an exchange offer to exchange the unregistered 2024 Senior Notes for registered notes, as well as all related guarantees. ​ On July 21, 2020, the Company completed a cash tender offer at par for up to $639 million in aggregate principal amount of the 2024 Notes and the 2027 Senior Notes. The Company accepted for purchase all of 2024 Notes validly tendered and not validly withdrawn pursuant to the cash tender offer, amounting to $2.7 million aggregate principal amount of the 2024 Notes at par. The Company made the cash tender offer at par to satisfy obligations under the indentures governing the 2024 Notes and the 2027 Senior Notes relating to the use of certain cash proceeds from its disposition of the Management Services business, which was completed on January 31, 2020. On April 26, 2021, the Company completed a cash tender offer for up to $700 million in aggregate purchase price (not including any accrued and unpaid interest) of the 2024 Notes. The Company accepted for purchase all of 2024 Notes validly tendered and not validly withdrawn pursuant to the cash tender offer, amounting to $608.3 million aggregate principal amount of the 2024 Notes. The aggregate purchase price paid by the Company in connection with the tender offer was $697.2 million (inclusive of the tender offer premiums paid pursuant to the terms of the tender offer), plus accrued and unpaid interest. The amounts paid were funded using the proceeds from the Term B Facility described above and cash on hand. On April 6, 2021, the Company, the guarantors with respect to the 2024 Notes, and the trustee with respect to the 2024 Notes executed and delivered a supplemental indenture to the 2024 Notes (Supplemental Indenture), which became effective on April 6, 2021. The Supplemental Indenture became operative on April 13, 2021, upon the Company’s acceptance of the 2024 Notes for purchase and payment therefore at the early settlement date of the April 2021 tender offer. ​ With respect to the Supplemental Indenture, each of the following sections in the indenture relating to the 2024 Notes were deleted: (i) Section 4.03, “SEC Reports”; (ii) Section 4.04, “Compliance Certificate”; (iii) Section 4.05, “Taxes”; (iv) Section 4.06, “Stay, Extension and Usury Laws”; (v) Section 4.07, “Limitation on Restricted Payments”; (vi) Section 4.08, “Limitation on Restrictions on Distributions from Restricted Subsidiaries”; (vii) Section 4.09, “Limitations on Indebtedness”; (viii) Section 4.10, “Limitation on Sales of Assets and Subsidiary Stock”; (ix) Section 4.11, “Limitation on Transactions with Affiliates”; (x) Section 4.12, “Limitation on Liens”; (xi) Section 4.14, “Change of Control”; (xii) Section 4.18, “Future Subsidiary Guarantors”; (xiii) Section 4.19, “Suspension of Covenants”; (xiv) Section 4.20, “Additional Interest Notice”; and (xv) Section 6.01(a), “Events of Default” (subsections (3) through (7) thereof (inclusive)). Certain modifications to Section 3.01, “Notices to Trustee”; Section 3.02(a) “Selection of Notes to Be Redeemed”; Section 3.03(a) “Notice of Redemption”; Section 4.15 “Corporate Existence”; Section 5.01, “Merger and Consolidation”; and Section 5.02, “Successor Corporation” were also made. On June 25, 2021, the Company redeemed its remaining 2024 Notes. The redemption price of the 2024 Notes was 115.108% of the remaining outstanding aggregate principal amount, amounting to $217.5 million, plus accrued and unpaid interest. The amounts paid were funded using the proceeds from the additional draw down from the Term A Facility described above and cash on hand. The redemption of the 2024 Notes in the third quarter of fiscal 2021 resulted in a $117.5 million prepayment premium, which was included interest expense. 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 June 30, 2021, the estimated fair value of the 2027 Senior Notes was approximately $1,109.5 million. The fair value of the 2027 Senior Notes as of June 30, 2021 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. ​ 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 June 30, 2021. ​ URS Senior Notes ​ In connection with the 2014 acquisition of the URS Corporation (URS), the Company assumed the URS 5.00% Senior Notes due 2022 (2022 URS Senior Notes). ​ The remaining $248.5 million principal amount of the 2022 URS Senior Notes were fully redeemed on August 31, 2020 using proceeds from a $248.5 million secured delayed draw term loan facility under the Credit Agreement, at a redemption price that was 106.835 % of the principal amount outstanding plus accrued and unpaid interest. The August 31, 2020 redemption resulted in a $17.0 million prepayment premium, which was included in interest expense during the year ended September 30, 2020. ​ 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 June 30, 2021 and September 30, 2020, these outstanding standby letters of credit totaled $489.6 million and $510.1 million, respectively. As of June 30, 2021, the Company had $443.1 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 agreements and excluding the effects of prepayment premiums included in interest expense, during the nine months ended June 30, 2021 and 2020 was 4.7% and 5.2%, respectively. ​ Interest expense in the consolidated statements of operations included amortization of deferred debt issuance costs for the three and nine months ended June 30, 2021 of $4.6 million and $9.0 million, respectively, and for the three and nine months ended June 30, 2020 of $1.3 million and $3.8 million, respectively.

Derivative Financial Instrument

Derivative Financial Instruments and Fair Value Measurements	9 Months Ended
	Jun. 30, 2021
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 agreements designated as cash flow hedges to fix the 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. The gain or loss is subsequently reclassified to 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 agreements would be recognized in other income. ​ The notional principal, fixed rates, and related expiration dates of the Company’s outstanding interest rate swap agreements were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30,2021 Notional Amount ​ Notional Amount ​ Fixed ​ Expiration Currency (in millions) Rate Date USD ​ 200.0 2.60% ​ February 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2020 Notional Amount ​ Notional Amount ​ Fixed ​ Expiration Currency (in millions) Rate Date USD ​ 200.0 2.60% ​ February 2023 ​ Subsequent to the end of the third 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 will become effective February 2023 and terminate in March 2028. By entering into the swap agreements, the Company converted a portion of the LIBOR rate-based liability into a fixed rate liability. The Company will pay a fixed rate of 1.349% and receive payment at the prevailing one-month LIBOR. ​ 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 nine months ended June 30, 2021 and 2020. ​ Fair Value Measurements ​ The Company’s non-pension financial assets and liabilities recorded at fair values relate to derivative instruments and were not material at June 30, 2021 or September 30, 2020. ​ See Note 14 for accumulated balances and reporting period activities of derivatives related to reclassifications out of accumulated other comprehensive loss for the nine months ended June 30, 2021 and 2020. Amounts recognized in accumulated other comprehensive loss from the Company’s foreign currency options were immaterial for all periods presented. Amounts reclassified from accumulated other comprehensive loss into income from the foreign currency options were immaterial for all periods presented. Additionally, there were no material losses recognized in income due to amounts excluded from effectiveness testing from the Company’s interest rate swap agreements.

Share-based Payments

Share-based Payments	9 Months Ended
	Jun. 30, 2021
Share-based Payments
Share-based Payments	9. Share-based Payments ​ The fair value of the Company’s employee stock option awards is estimated on the date of grant. The expected term of awards granted represents the period of time the awards are expected to be outstanding. The risk-free interest rate is based on U.S. Treasury bond rates with maturities equal to the expected term of the stock option on the grant date. The Company uses historical data as a basis to estimate the probability of forfeitures. ​ Stock option activity for the nine months ended June 30 was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ 2020 ​ ​ Shares of stock ​ Weighted average ​ Shares of stock ​ Weighted average ​ under options exercise price under options exercise price ​ ​ (in millions) ​ ​ ​ ​ (in millions) ​ ​ ​ Outstanding at September 30 ​ 0.4 ​ $ 36.41 0.1 ​ $ 31.62 Options granted — ​ — — ​ — Options exercised (0.1) ​ 31.62 — ​ — Options forfeited or expired — ​ — — ​ — Outstanding at June 30 0.3 ​ 38.72 0.1 ​ 31.62 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Vested and expected to vest in the future as of June 30 ​ 0.2 ​ $ 38.72 0.1 ​ $ 31.62 ​ 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 that day’s closing market price of the Company’s common stock. The weighted average grant date fair value of PEP awards was $52.76 and $42.99 during the nine months ended June 30, 2021 and 2020, respectively. The weighted average grant date fair value of restricted stock unit awards was $49.21 and $42.25 during the nine months ended June 30, 2021 and 2020, respectively. Total compensation expense related to these share-based payments including stock options was

Income Taxes

Income Taxes	9 Months Ended
	Jun. 30, 2021
Income Taxes
Income Taxes	10. Income Taxes ​ The Company’s effective tax rate was 16.6% and 14.2% for the nine months ended June 30, 2021 and 2020, 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 nine-month period ended June 30, 2021 were a tax benefit of $39.0 million related to income tax credits and incentives, a tax benefit of $25.9 million related to a corporate tax rate change in the United Kingdom, a tax expense of $30.7 million related to foreign residual income, a tax expense of $13.2 million related to an audit settlement, and a tax expense of $11.5 million related to state income taxes. All of these items are expected to have a continuing impact on the effective tax rate for the remainder of the fiscal year except for the tax rate change and the audit settlement. ​ The most significant items contributing to the difference between the statutory U.S. federal income tax rate of 21.0% and the Company’s effective tax rate for the nine-month period ended June 30, 2020 were a tax benefit of $25.4 million related to the release of a valuation allowance on net operating losses and a benefit of $22.9 million related to income tax credits and incentives, partially offset by tax expense of $21.7 million related to nondeductible costs and tax expense of $9.0 million related to state income tax. ​ During the third quarter of fiscal 2021, the United Kingdom enacted a corporate tax rate increase from 19% to 25% beginning April 2023 requiring deferred tax assets and liabilities to be remeasured. The remeasurement resulted in a $25.9 million tax benefit. ​ During the third quarter of fiscal 2021, the Company partially settled its U.S. federal audit for fiscal 2015 and 2016 and recorded a tax expense of $13.2 million due primarily to changes in tax attributes. ​ During the third quarter of fiscal 2020, management approved a tax planning strategy and it began restructuring certain operations in Canada which resulted in the release of a valuation allowance related to net operating losses in the amount of $25.4 million. ​ 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. federal government has recently proposed significant legislation that would increase the U.S. corporate tax rate and impact how corporations are taxed. In addition, many international legislative and regulatory bodies have proposed legislation that could significantly impact how our international business activities are taxed. These proposed changes, if enacted, 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. and believes the outcomes which are reasonably possible within the next twelve months, including lapses in statutes of limitations, could result in future adjustments, but will not result in a material change in the liability for uncertain tax positions. ​ 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 $1.5 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	9 Months Ended
	Jun. 30, 2021
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 nine months ended June 30, 2021 and 2020, 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 ​ Nine Months Ended ​ ​ June 30, ​ June 30, June 30, June 30, ​ 2021 2020 2021 2020 ​ ​ (in millions) Denominator for basic earnings per share 146.1 160.1 148.4 158.7 Potential common shares 2.8 1.7 2.3 2.4 Denominator for diluted earnings per share 148.9 161.8 150.7 161.1 ​

Leases

Leases	9 Months Ended
	Jun. 30, 2021
Leases
Leases	12. Leases ​ On October 1, 2019, the Company adopted FASB ASC 842 on a modified retrospective basis, which amended the accounting standards for leases. Accordingly, the Company applied the new guidance as of the date of adoption with a cumulative-effect adjustment recorded through equity. Prior periods have not been restated as a result of the adoption. Retained earnings decreased $87.8 million due to the adoption, primarily from impairment of the right-of-use assets associated with office building leases. ​ The Company also applied transition elections that allow it to avoid reassessment of lease definition, classification, or direct costs relating to expired or expiring leases. Adoption of the new lease guidance did not significantly change the Company’s accounting for finance leases, which were previously referred to as capital 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 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 ​ Nine Months Ended ​ June 30,2021 June 30,2020 June 30,2021 June 30,2020 ​ ​ (in millions) Operating lease cost ​ $ 46.3 ​ $ 49.3 ​ $ 141.0 ​ $ 144.7 Finance lease cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ 3.9 ​ ​ 4.2 ​ ​ 10.3 ​ ​ 13.9 Interest on lease liabilities ​ 0.6 ​ ​ 0.4 ​ ​ 1.8 ​ ​ 1.4 Variable lease cost ​ 8.5 ​ ​ 8.8 ​ ​ 27.2 ​ ​ 27.1 Total lease cost ​ $ 59.3 ​ $ 62.7 ​ $ 180.3 ​ $ 187.1 ​ Additional balance sheet information related to leases is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of (in millions except as noted) Balance Sheet Classification June 30,2021 September 30, 2020 Assets: ​ ​ ​ ​ Operating lease assets Operating lease right-of-use assets ​ $ 637.3 ​ $ 652.1 Finance lease assets Property and equipment – net ​ ​ 41.1 ​ 29.1 Total lease assets ​ $ 678.4 ​ $ 681.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ Current: ​ ​ ​ ​ ​ Operating lease liabilities Accrued expenses and other current liabilities ​ $ 162.8 ​ $ 168.4 Finance lease liabilities Current portion of long-term debt ​ ​ 14.1 ​ 9.8 Total current lease liabilities ​ $ 176.9 ​ $ 178.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-current: ​ ​ ​ ​ ​ ​ Operating lease liabilities Operating lease liabilities, noncurrent ​ ​ 711.5 ​ 745.3 Finance lease liabilities Long-term debt ​ ​ 30.5 ​ 22.0 Total non-current lease liabilities ​ $ 742.0 ​ $ 767.3 ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ June 30, 2021 September 30, 2020 ​ Weighted average remaining lease term (in years): ​ ​ ​ Operating leases 7.0 ​ 7.3 ​ Finance leases 3.3 ​ 3.3 ​ Weighted average discount rates: ​ ​ ​ ​ Operating leases 4.4 % 4.6 % Finance leases 4.6 % 4.7 % ​ Additional cash flow information related to leases is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ June 30, ​ June 30, ​ 2021 2020 ​ ​ (in millions) Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 165.9 ​ $ 168.3 Operating cash flows from finance leases ​ ​ 1.5 ​ 1.3 Financing cash flows from finance leases ​ ​ 10.1 ​ 11.9 Right-of-use assets obtained in exchange for new operating leases ​ ​ 77.3 ​ 90.8 Right-of-use assets obtained in exchange for new finance leases ​ ​ 22.2 ​ 17.5 ​ Total remaining lease payments under both the Company’s operating and finance leases are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Finance Leases Fiscal Year ​ (in millions) 2021 (three months remaining) ​ $ 53.0 ​ $ 3.9 2022 ​ 188.6 ​ 15.6 2023 ​ 155.0 ​ 13.4 2024 ​ 132.9 ​ 9.8 2025 ​ ​ 113.0 ​ 4.5 Thereafter ​ 376.1 ​ 0.8 Total lease payments ​ $ 1,018.6 ​ $ 48.0 Less: Amounts representing interest ​ $ (144.3) ​ $ (3.4) Total lease liabilities ​ $ 874.3 ​ $ 44.6 ​

Other Financial Information

Other Financial Information	9 Months Ended
	Jun. 30, 2021
Other Financial Information
Other Financial Information	13. Other Financial Information ​ Accrued expenses and other current liabilities consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, September 30, ​ ​ 2021 ​ 2020 ​ ​ (in millions) Accrued salaries and benefits ​ $ 702.2 ​ $ 675.7 Accrued contract costs ​ 1,252.3 ​ 1,137.5 Other accrued expenses ​ 380.6 ​ 436.5 ​ ​ $ 2,335.1 ​ $ 2,249.7 ​ Accrued contract costs above include balances related to professional liability accruals of $800.4 million and $625.9 million as of June 30, 2021 and September 30, 2020, 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 June 30, 2021 and September 30, 2020. The Company did not have material revisions to estimates for contracts where revenue is recognized using the percentage-of-completion method during the nine months ended June 30, 2021 and 2020. In the first quarter of fiscal 2019, the Company commenced a restructuring plan to improve profitability. The Company expects to incur restructuring costs of $40 million to $50 million in fiscal year 2021 primarily related to costs associated with the advancing its previously announced actions to deliver margin improvement and efficiencies that result in a more agile organization. During the first nine months of fiscal 2021, the Company incurred restructuring expenses of $34.8 million, including personnel and other costs of $25.8 million and real estate costs of $9.0 million, of which $6.5 million was accrued and unpaid at June 30, 2021. During the first nine months of fiscal 2020, the Company incurred restructuring expenses of $96.4 million, including personnel and other costs of $83.5 million and real estate costs of $12.9 million.

Reclassifications out of Accumu

Reclassifications out of Accumulated Other Comprehensive Loss	9 Months Ended
	Jun. 30, 2021
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 nine months ended June 30, 2021 and 2020 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 March 31, 2021 ​ $ (353.5) ​ $ (535.6) ​ $ (6.6) ​ $ (895.7) Other comprehensive income (loss) before reclassification ​ 0.2 ​ ​ (18.8) ​ ​ (0.1) ​ ​ (18.7) Amounts reclassified from accumulated other comprehensive loss ​ 3.0 ​ ​ — ​ ​ 0.9 ​ ​ 3.9 Balances at June 30,2021 ​ $ (350.3) ​ $ (554.4) ​ $ (5.8) ​ $ (910.5) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at March 31, 2020 ​ $ (280.0) ​ $ (592.1) ​ $ (9.5) ​ $ (881.6) Other comprehensive income (loss) before reclassification ​ 1.7 ​ 71.4 ​ (0.8) ​ 72.3 Amounts reclassified from accumulated other comprehensive loss ​ 2.9 ​ — ​ 0.8 ​ 3.7 Balances at June 30, 2020 ​ $ (275.4) ​ $ (520.7) ​ $ (9.5) ​ $ (805.6) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at September 30, 2020 ​ $ (342.8) ​ $ (567.3) ​ $ (8.6) ​ $ (918.7) Other comprehensive (loss) income before reclassification ​ ​ (16.5) ​ 12.9 ​ 0.1 ​ (3.5) Amounts reclassified from accumulated other comprehensive loss ​ ​ 9.0 ​ ​ — ​ ​ 2.7 ​ ​ 11.7 Balances at June 30,2021 ​ $ (350.3) ​ $ (554.4) ​ $ (5.8) ​ $ (910.5) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at September 30, 2019 ​ $ (302.7) ​ $ (548.7) ​ $ (12.8) ​ $ (864.2) Other comprehensive (loss) income before reclassification ​ (2.0) ​ 28.0 ​ (5.3) ​ 20.7 Amounts reclassified from accumulated other comprehensive loss ​ ​ 29.3 ​ ​ — ​ ​ 8.6 ​ ​ 37.9 Balances at June 30, 2020 ​ $ (275.4) ​ $ (520.7) ​ $ (9.5) ​ $ (805.6) ​

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Jun. 30, 2021
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 enters 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. 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 June 30, 2021, the Company was contingently liable in the amount of approximately $500.2 million in issued standby letters of credit and $3.8 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 June 30, 2021, the Company has capital commitments of $20.3 million to the Fund over the next 8 years . ​ In addition, in connection with the investment activities of AECOM Capital, the Company provides guarantees of contractual obligations, including guarantees for completion of projects, repayment of debt, environmental indemnity obligations and other lender required guarantees. ​ Department of Energy Deactivation, Demolition, and Removal Project ​ AECOM Energy and Construction, Inc., an Ohio corporation, a former affiliate of the Company (“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 to the Purchaser including the Former Affiliate who worked on the DOE project. The Company and the Purchaser agreed that all future DOE project claim recoveries and costs will be split 10% to the 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 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. ​ New York Department of Environmental Conservation ​ In September 2017, AECOM USA, Inc. was advised by the New York State Department of Environmental Conservation (DEC) of allegations that it committed environmental permit violations pursuant to the New York Environmental Conservation Law (ECL) associated with AECOM USA, Inc.’s oversight of a stream restoration project for Schoharie County which could result in substantial penalties if calculated under the ECL’s maximum civil penalty provisions. AECOM USA, Inc. disputes this claim and intends to continue to defend this matter vigorously; however, AECOM USA, Inc. cannot provide assurances that it will be successful in these efforts. The potential range of loss in excess of any current accrual cannot be reasonably estimated at this time primarily because the matter involves complex and unique environmental and regulatory issues; the project site involves the oversight and involvement of various local, state and federal government agencies; there is substantial uncertainty regarding any alleged damages; and the matter is in its preliminary stages. ​ 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 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 Thirteen 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. The parties have agreed on a February 28, 2022 deadline for close of discovery in this matter. ​ On January 31, 2020, the Company completed the sale of its Management Services business to the Purchaser including the Former Affiliate, however, the Refinery Turnaround Project, including related claims and liabilities, has been retained by the Company. ​ 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 Company is continuing to assess.

Reportable Segments

Reportable Segments	9 Months Ended
	Jun. 30, 2021
Reportable Segments
Reportable Segments	16. Reportable Segments ​ During the first quarter of fiscal 2020, the Company reorganized its operating and reporting structure to better align with its ongoing professional services business. This reorganization better reflects the continuing operations of the Company after the sale of its former Management Services reportable business segment and planned disposal of its self-perform at-risk construction businesses discussed in Note 3. The businesses that comprised the Company’s former Management Services reportable business segment and the civil infrastructure, power and oil and gas construction businesses in the former Construction Services reportable business segment were classified as discontinued operations. The former Design and Consulting Services reportable business segment and construction management business in the former Construction Services reportable business segment were reformed around geographic regions. The Americas segment provides planning, consulting, architectural and engineering design services, and construction management services to commercial and government clients in the United States, Canada, and Latin America, while the International segment provides similar professional services to commercial and government clients in Europe, the Middle East, Africa, and the Asia-Pacific regions. ​ The Company’s AECOM Capital (ACAP) segment primarily invests in and develops real estate projects. 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 various operating segments into its 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 change in reportable segments was applied to all periods presented. ​ 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 June 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 2,618.5 ​ $ 789.3 ​ $ 0.6 ​ $ — ​ $ 3,408.4 ​ Gross profit ​ 160.6 ​ 40.4 ​ 0.6 ​ ​ — ​ ​ 201.6 ​ Equity in earnings of joint ventures ​ 3.2 ​ 5.1 ​ (0.1) ​ ​ — ​ ​ 8.2 ​ General and administrative expenses ​ — ​ — ​ (2.4) ​ ​ (33.9) ​ ​ (36.3) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (13.0) ​ ​ (13.0) ​ Operating income (loss) ​ 163.8 ​ 45.5 ​ (1.9) ​ ​ (46.9) ​ ​ 160.5 ​ Gross profit as a % of revenue ​ 6.1 % 5.1 % — ​ ​ — ​ ​ 5.9 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 2,471.6 ​ $ 717.9 ​ $ 0.2 ​ $ — ​ $ 3,189.7 ​ Gross profit ​ 155.3 ​ 29.6 ​ ​ 0.2 ​ — ​ 185.1 ​ Equity in earnings of joint ventures ​ 5.6 ​ 2.7 ​ ​ 0.3 ​ — ​ 8.6 ​ General and administrative expenses ​ — ​ — ​ ​ (1.1) ​ (53.4) ​ (54.5) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (20.3) ​ ​ (20.3) ​ Operating income (loss) ​ ​ 160.9 ​ ​ 32.3 ​ ​ (0.6) ​ ​ (73.7) ​ ​ 118.9 ​ Gross profit as a % of revenue ​ 6.3 % ​ 4.1 % ​ — ​ ​ — ​ ​ 5.8 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended June 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 7,644.1 ​ $ 2,341.4 ​ $ 1.6 ​ $ — ​ $ 9,987.1 ​ Gross profit ​ ​ 457.3 ​ ​ 122.3 ​ ​ 1.6 ​ ​ — ​ ​ 581.2 ​ Equity in earnings of joint ventures ​ ​ 7.6 ​ ​ 11.1 ​ ​ 4.9 ​ ​ — ​ ​ 23.6 ​ General and administrative expenses ​ ​ — ​ ​ — ​ ​ (5.8) ​ ​ (104.9) ​ ​ (110.7) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (34.8) ​ ​ (34.8) ​ Operating income ​ ​ 464.9 ​ ​ 133.4 ​ ​ 0.7 ​ ​ (139.7) ​ ​ 459.3 ​ Gross profit as a % of revenue ​ ​ 6.0 % ​ 5.2 % ​ — ​ ​ — ​ ​ 5.8 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended June 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 7,399.2 ​ $ 2,270.6 ​ $ 1.2 ​ $ — ​ $ 9,671.0 ​ Gross profit ​ 430.3 ​ 88.2 ​ ​ 1.2 ​ — ​ 519.7 ​ Equity in earnings of joint ventures ​ 17.3 ​ 8.7 ​ ​ 6.0 ​ — ​ 32.0 ​ General and administrative expenses ​ — ​ — ​ ​ (5.3) ​ (133.9) ​ (139.2) ​ Restructuring costs ​ — ​ — ​ ​ — ​ (96.4) ​ (96.4) ​ Operating income ​ 447.6 ​ 96.9 ​ ​ 1.9 ​ (230.3) ​ 316.1 ​ Gross profit as a % of revenue ​ 5.8 % 3.9 % ​ — ​ ​ — ​ 5.4 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reportable Segments: ​ ​ ​ ​ ​ ​ ​ ​ Total assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2021 ​ $ 7,695.0 ​ $ 2,503.8 ​ $ 221.7 ​ $ 1,415.5 September 30, 2020 ​ ​ 8,104.4 ​ ​ 2,454.0 ​ ​ 198.0 ​ ​ 1,625.8 ​

Discontinued Operations, Good_2

Discontinued Operations, Goodwill, and Intangible Assets (Tables)	9 Months Ended
	Jun. 30, 2021
Discontinued Operations, Goodwill, and Intangible Assets
Summarized results of the discontinued operation, included in the Company's results of operations	The following table represents summarized balance sheet information of assets and liabilities held for sale (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ September 30, ​ 2021 2020 ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 5.8 ​ $ 109.9 Receivables and contract assets ​ 70.9 ​ 414.3 Other ​ 50.3 ​ 38.2 Current assets held for sale ​ $ 127.0 ​ $ 562.4 ​ ​ ​ ​ ​ ​ ​ Property and equipment, net ​ $ 52.4 ​ $ 119.8 Other ​ 19.0 ​ 181.8 Write-down of assets to fair value less cost to sell ​ ​ (71.4) ​ ​ (247.2) Non-current assets held for sale ​ $ — ​ $ 54.4 ​ ​ ​ ​ ​ ​ ​ Accounts payable and accrued expenses ​ $ 76.9 ​ $ 350.4 Contract liabilities ​ 9.2 ​ 65.6 Other ​ 4.8 ​ 1.6 Current liabilities held for sale ​ $ 90.9 ​ $ 417.6 ​ ​ ​ ​ ​ ​ ​ Long-term liabilities held for sale ​ $ 12.3 ​ $ 79.3 ​ The following table represents summarized income statement information of discontinued operations (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended Nine months ended ​ ​ June 30, ​ June 30, June 30, ​ June 30, ​ 2021 2020 2021 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 162.9 ​ $ 347.5 ​ $ 606.6 ​ $ 2,661.8 Cost of revenue ​ 159.6 ​ 352.5 ​ ​ 600.4 ​ ​ 2,708.5 Gross profit (loss) ​ 3.3 ​ (5.0) ​ ​ 6.2 ​ ​ (46.7) Equity in earnings (losses) of joint ventures ​ (3.4) ​ (11.1) ​ ​ 4.6 ​ ​ (28.0) (Loss) gain on disposal activities ​ ​ (6.1) ​ ​ 14.9 ​ ​ (56.2) ​ ​ 161.9 Transaction costs ​ ​ (0.7) ​ ​ — ​ ​ (14.3) ​ ​ (41.4) Impairment of long-lived assets ​ ​ (9.4) ​ ​ — ​ ​ (105.2) ​ ​ (89.3) Loss from operations ​ (16.3) ​ (1.2) ​ ​ (164.9) ​ ​ (43.5) Other (expense) income ​ — ​ (0.2) ​ ​ — ​ ​ 1.6 Interest expense ​ (0.1) ​ (1.5) ​ ​ (0.4) ​ ​ (40.2) Loss before taxes ​ (16.4) ​ (2.9) ​ ​ (165.3) ​ ​ (82.1) Income tax (benefit) expense ​ (0.9) ​ (2.8) ​ ​ (46.1) ​ ​ 30.6 Net loss from discontinued operations ​ $ (15.5) ​ $ (0.1) ​ $ (119.2) ​ $ (112.7) ​ The significant components included in the Consolidated Statement of Cash Flows for the discontinued operations are as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended Nine months ended ​ ​ June 30, June 30, ​ June 30, June 30, ​ 2021 ​ 2020 2021 ​ 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization: ​ ​ ​ ​ ​ ​ ​ ​ Property and equipment ​ $ — ​ $ — ​ $ — ​ $ 4.6 Intangible assets and capitalized debt issuance costs ​ $ — ​ $ 4.3 ​ $ — ​ $ 35.8 Payments for capital expenditures ​ $ (2.0) ​ $ (2.6) ​ $ (6.6) ​ $ (16.8) ​
Schedule of changes in the carrying value of goodwill by reportable segment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ ​ September 30, ​ Exchange ​ June 30, ​ 2020 Impact 2021 ​ ​ (in millions) Americas ​ $ 2,617.1 ​ $ 14.2 ​ $ 2,631.3 International ​ 867.1 ​ 18.4 ​ 885.5 Total ​ $ 3,484.2 ​ $ 32.6 ​ $ 3,516.8
Schedule of finite-lived intangible assets by major class	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2021 ​ September 30, 2020 ​ ​ ​ ​ Gross ​ Accumulated ​ Intangible ​ Gross ​ Accumulated ​ Intangible ​ Amortization ​ Amount Amortization Assets, Net Amount Amortization Assets, Net Period ​ ​ (in millions) ​ (years) Backlog and customer relationships ​ $ 663.5 ​ $ (601.8) ​ $ 61.7 ​ $ 662.8 ​ $ (585.9) ​ $ 76.9 1 - 11
Schedule of estimated future amortization expense of intangible assets	​ ​ ​ ​ ​ Fiscal Year (in millions) 2021 (three months remaining) ​ $ 4.9 2022 ​ 19.8 2023 ​ 18.8 2024 ​ 17.4 2025 ​ ​ 0.8 Total ​ $ 61.7

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Jun. 30, 2021
Revenue Recognition
Schedule of revenues disaggregated by revenue sources	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ June 30, ​ June 30, ​ June 30, ​ June 30, ​ 2021 2020 2021 2020 ​ (in millions) Cost reimbursable ​ $ 1,309.2 ​ $ 1,369.3 ​ $ 4,041.8 ​ $ 4,252.5 Guaranteed maximum price ​ 1,229.9 ​ ​ 829.8 ​ ​ 3,443.0 ​ ​ 2,706.4 Fixed price ​ 869.3 ​ ​ 990.6 ​ ​ 2,502.3 ​ ​ 2,712.1 Total revenue ​ $ 3,408.4 ​ $ 3,189.7 ​ $ 9,987.1 ​ $ 9,671.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ June 30, ​ June 30, ​ June 30, ​ June 30, ​ 2021 2020 2021 2020 ​ (in millions) Americas ​ $ 2,619.0 ​ $ 2,471.8 ​ $ 7,645.7 ​ $ 7,400.5 Europe, Middle East, Africa ​ 401.3 ​ ​ 359.9 ​ ​ 1,201.8 ​ ​ 1,194.9 Asia Pacific ​ 388.1 ​ ​ 358.0 ​ ​ 1,139.6 ​ ​ 1,075.6 Total revenue ​ $ 3,408.4 ​ $ 3,189.7 ​ $ 9,987.1 ​ $ 9,671.0 ​
Schedule of net accounts receivable	​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ September 30, ​ ​ 2021 2020 ​ ​ (in millions) Billed ​ $ 2,225.0 ​ $ 2,467.3 Contract retentions ​ 541.6 ​ ​ 531.3 Total accounts receivable—gross ​ 2,766.6 ​ ​ 2,998.6 Allowances for doubtful accounts and credit losses ​ (97.5) ​ ​ (77.9) Total accounts receivable—net ​ $ 2,669.1 ​ $ 2,920.7

Joint Ventures and Variable I_2

Joint Ventures and Variable Interest Entities (Tables)	9 Months Ended
	Jun. 30, 2021
Joint Ventures and Variable Interest Entities
Summary of financial information of the consolidated joint ventures	​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ ​ ​ ​ ​ 2021 ​ September 30, ​ ​ (unaudited) 2020 ​ ​ (in millions) Current assets ​ $ 530.2 ​ $ 536.3 Non-current assets ​ 75.3 ​ 77.0 Total assets ​ $ 605.5 ​ $ 613.3 ​ ​ ​ ​ ​ ​ ​ Current liabilities ​ $ 390.2 ​ $ 409.9 Non-current liabilities ​ 1.5 ​ 1.5 Total liabilities ​ 391.7 ​ 411.4 Total AECOM equity ​ 118.1 ​ 113.9 Noncontrolling interests ​ 95.7 ​ 88.0 Total owners’ equity ​ 213.8 ​ 201.9 Total liabilities and owners’ equity ​ $ 605.5 ​ $ 613.3
Summary of financial information of the unconsolidated joint ventures, as derived from their unaudited financial statements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ September 30, ​ ​ 2021 2020 ​ ​ (in millions) Current assets ​ $ 1,345.7 ​ $ 1,374.3 Non-current assets ​ 546.2 ​ 465.9 Total assets ​ $ 1,891.9 ​ $ 1,840.2 ​ ​ ​ ​ ​ ​ ​ Current liabilities ​ $ 912.1 ​ $ 953.4 Non-current liabilities ​ 57.2 ​ 58.9 Total liabilities ​ 969.3 ​ 1,012.3 Joint ventures’ equity ​ 922.6 ​ 827.9 Total liabilities and joint ventures’ equity ​ $ 1,891.9 ​ $ 1,840.2 ​ ​ ​ ​ ​ ​ ​ AECOM’s investment in joint ventures ​ $ 332.0 ​ $ 297.6 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ June 30, ​ June 30, ​ 2021 2020 ​ ​ (in millions) Revenue ​ $ 1,588.4 ​ $ 2,325.7 Cost of revenue ​ 1,539.8 ​ 2,281.7 Gross profit ​ $ 48.6 ​ $ 44.0 Net income ​ $ 41.8 ​ $ 42.7
Summary of AECOM's equity in earnings of unconsolidated joint ventures	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ June 30, June 30, ​ 2021 2020 ​ (in millions) Pass through joint ventures ​ $ 18.8 ​ $ 26.0 Other joint ventures ​ 4.8 ​ ​ 6.0 Total ​ $ 23.6 ​ $ 32.0

Pension Benefit Obligations (Ta

Pension Benefit Obligations (Tables)	9 Months Ended
	Jun. 30, 2021
Pension Benefit Obligations
Components of net periodic cost for the Company's pension and post-retirement plans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ June 30,2021 ​ June 30,2020 ​ June 30,2021 ​ June 30,2020 ​ 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 ​ $ — ​ $ 0.4 ​ $ — ​ $ 0.4 Interest cost on projected benefit obligation ​ 1.1 ​ ​ 5.5 ​ ​ 1.6 ​ ​ 5.4 ​ 3.2 ​ ​ 16.2 ​ ​ 4.8 ​ ​ 16.7 Expected return on plan assets ​ (1.6) ​ ​ (11.1) ​ ​ (1.8) ​ ​ (9.1) ​ (4.8) ​ ​ (32.6) ​ ​ (5.3) ​ ​ (27.9) Amortization of prior service cost ​ ​ — ​ ​ 0.1 ​ ​ — ​ ​ — ​ ​ — ​ ​ 0.1 ​ ​ 0.1 ​ ​ — Amortization of net loss ​ 1.4 ​ ​ 2.4 ​ ​ 1.3 ​ ​ 2.1 ​ 4.4 ​ ​ 6.9 ​ ​ 3.7 ​ ​ 6.4 Curtailment loss recognized ​ ​ — ​ ​ — ​ ​ 0.5 ​ ​ — ​ ​ — ​ ​ — ​ ​ 0.5 ​ ​ — Settlement loss recognized ​ ​ 0.1 ​ ​ — ​ ​ — ​ ​ — ​ ​ 0.1 ​ ​ — ​ ​ 0.5 ​ ​ 0.2 Net periodic benefit cost ​ $ 1.0 ​ $ (3.0) ​ $ 1.6 ​ $ (1.5) ​ $ 2.9 ​ $ (9.0) ​ $ 4.3 ​ $ (4.2)

Debt (Tables)

Debt (Tables)	9 Months Ended
	Jun. 30, 2021
Debt
Schedule of debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ September 30, ​ 2021 2020 ​ ​ (in millions) Credit Agreement ​ $ 1,156.9 ​ $ 248.5 2024 Senior Notes ​ ​ — ​ ​ 797.3 2027 Senior Notes ​ ​ 997.3 ​ ​ 997.3 Other debt ​ 79.7 ​ 41.9 Total debt ​ 2,233.9 ​ 2,085.0 Less: Current portion of debt and short-term borrowings ​ (55.2) ​ (20.9) Less: Unamortized debt issuance costs ​ ​ (24.9) ​ ​ (23.0) Long-term debt ​ $ 2,153.8 ​ $ 2,041.1
Schedule of maturities of debt	​ ​ ​ ​ ​ Fiscal Year ​ ​ 2021 (three months remaining) ​ $ 14.9 2022 ​ 48.2 2023 ​ 38.1 2024 ​ 39.4 2025 ​ 34.2 Thereafter ​ 2,059.1 Total ​ $ 2,233.9

Derivative Financial Instrume_2

Derivative Financial Instruments and Fair Value Measurements (Tables)	9 Months Ended
	Jun. 30, 2021
Derivative Financial Instruments and Fair Value Measurements
Notional principle, fixed rates and related expiration dates of outstanding interest rate swap agreements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30,2021 Notional Amount ​ Notional Amount ​ Fixed ​ Expiration Currency (in millions) Rate Date USD ​ 200.0 2.60% ​ February 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2020 Notional Amount ​ Notional Amount ​ Fixed ​ Expiration Currency (in millions) Rate Date USD ​ 200.0 2.60% ​ February 2023

Share-based Payments (Tables)

Share-based Payments (Tables)	9 Months Ended
	Jun. 30, 2021
Share-based Payments
Schedule of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ 2020 ​ ​ Shares of stock ​ Weighted average ​ Shares of stock ​ Weighted average ​ under options exercise price under options exercise price ​ ​ (in millions) ​ ​ ​ ​ (in millions) ​ ​ ​ Outstanding at September 30 ​ 0.4 ​ $ 36.41 0.1 ​ $ 31.62 Options granted — ​ — — ​ — Options exercised (0.1) ​ 31.62 — ​ — Options forfeited or expired — ​ — — ​ — Outstanding at June 30 0.3 ​ 38.72 0.1 ​ 31.62 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Vested and expected to vest in the future as of June 30 ​ 0.2 ​ $ 38.72 0.1 ​ $ 31.62

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Jun. 30, 2021
Earnings Per Share
Reconciliation of the denominators for basic and diluted EPS	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ June 30, ​ June 30, June 30, June 30, ​ 2021 2020 2021 2020 ​ ​ (in millions) Denominator for basic earnings per share 146.1 160.1 148.4 158.7 Potential common shares 2.8 1.7 2.3 2.4 Denominator for diluted earnings per share 148.9 161.8 150.7 161.1

Leases (Tables)

Leases (Tables)	9 Months Ended
	Jun. 30, 2021
Leases
Schedule of components of lease expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ June 30,2021 June 30,2020 June 30,2021 June 30,2020 ​ ​ (in millions) Operating lease cost ​ $ 46.3 ​ $ 49.3 ​ $ 141.0 ​ $ 144.7 Finance lease cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ 3.9 ​ ​ 4.2 ​ ​ 10.3 ​ ​ 13.9 Interest on lease liabilities ​ 0.6 ​ ​ 0.4 ​ ​ 1.8 ​ ​ 1.4 Variable lease cost ​ 8.5 ​ ​ 8.8 ​ ​ 27.2 ​ ​ 27.1 Total lease cost ​ $ 59.3 ​ $ 62.7 ​ $ 180.3 ​ $ 187.1
Schedule of additional balance sheet information related to leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of (in millions except as noted) Balance Sheet Classification June 30,2021 September 30, 2020 Assets: ​ ​ ​ ​ Operating lease assets Operating lease right-of-use assets ​ $ 637.3 ​ $ 652.1 Finance lease assets Property and equipment – net ​ ​ 41.1 ​ 29.1 Total lease assets ​ $ 678.4 ​ $ 681.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ Current: ​ ​ ​ ​ ​ Operating lease liabilities Accrued expenses and other current liabilities ​ $ 162.8 ​ $ 168.4 Finance lease liabilities Current portion of long-term debt ​ ​ 14.1 ​ 9.8 Total current lease liabilities ​ $ 176.9 ​ $ 178.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-current: ​ ​ ​ ​ ​ ​ Operating lease liabilities Operating lease liabilities, noncurrent ​ ​ 711.5 ​ 745.3 Finance lease liabilities Long-term debt ​ ​ 30.5 ​ 22.0 Total non-current lease liabilities ​ $ 742.0 ​ $ 767.3 ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ June 30, 2021 September 30, 2020 ​ Weighted average remaining lease term (in years): ​ ​ ​ Operating leases 7.0 ​ 7.3 ​ Finance leases 3.3 ​ 3.3 ​ Weighted average discount rates: ​ ​ ​ ​ Operating leases 4.4 % 4.6 % Finance leases 4.6 % 4.7 %
Schedule of additional cash flow information related to leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ June 30, ​ June 30, ​ 2021 2020 ​ ​ (in millions) Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 165.9 ​ $ 168.3 Operating cash flows from finance leases ​ ​ 1.5 ​ 1.3 Financing cash flows from finance leases ​ ​ 10.1 ​ 11.9 Right-of-use assets obtained in exchange for new operating leases ​ ​ 77.3 ​ 90.8 Right-of-use assets obtained in exchange for new finance leases ​ ​ 22.2 ​ 17.5
Schedule of total remaining lease payments under the Company's operating and finance leases	​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Finance Leases Fiscal Year ​ (in millions) 2021 (three months remaining) ​ $ 53.0 ​ $ 3.9 2022 ​ 188.6 ​ 15.6 2023 ​ 155.0 ​ 13.4 2024 ​ 132.9 ​ 9.8 2025 ​ ​ 113.0 ​ 4.5 Thereafter ​ 376.1 ​ 0.8 Total lease payments ​ $ 1,018.6 ​ $ 48.0 Less: Amounts representing interest ​ $ (144.3) ​ $ (3.4) Total lease liabilities ​ $ 874.3 ​ $ 44.6

Other Financial Information (Ta

Other Financial Information (Tables)	9 Months Ended
	Jun. 30, 2021
Other Financial Information
Schedule of accrued expenses and other current liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, September 30, ​ ​ 2021 ​ 2020 ​ ​ (in millions) Accrued salaries and benefits ​ $ 702.2 ​ $ 675.7 Accrued contract costs ​ 1,252.3 ​ 1,137.5 Other accrued expenses ​ 380.6 ​ 436.5 ​ ​ $ 2,335.1 ​ $ 2,249.7

Reclassifications out of Accu_2

Reclassifications out of Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Jun. 30, 2021
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 nine months ended June 30, 2021 and 2020 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 March 31, 2021 ​ $ (353.5) ​ $ (535.6) ​ $ (6.6) ​ $ (895.7) Other comprehensive income (loss) before reclassification ​ 0.2 ​ ​ (18.8) ​ ​ (0.1) ​ ​ (18.7) Amounts reclassified from accumulated other comprehensive loss ​ 3.0 ​ ​ — ​ ​ 0.9 ​ ​ 3.9 Balances at June 30,2021 ​ $ (350.3) ​ $ (554.4) ​ $ (5.8) ​ $ (910.5) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at March 31, 2020 ​ $ (280.0) ​ $ (592.1) ​ $ (9.5) ​ $ (881.6) Other comprehensive income (loss) before reclassification ​ 1.7 ​ 71.4 ​ (0.8) ​ 72.3 Amounts reclassified from accumulated other comprehensive loss ​ 2.9 ​ — ​ 0.8 ​ 3.7 Balances at June 30, 2020 ​ $ (275.4) ​ $ (520.7) ​ $ (9.5) ​ $ (805.6) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at September 30, 2020 ​ $ (342.8) ​ $ (567.3) ​ $ (8.6) ​ $ (918.7) Other comprehensive (loss) income before reclassification ​ ​ (16.5) ​ 12.9 ​ 0.1 ​ (3.5) Amounts reclassified from accumulated other comprehensive loss ​ ​ 9.0 ​ ​ — ​ ​ 2.7 ​ ​ 11.7 Balances at June 30,2021 ​ $ (350.3) ​ $ (554.4) ​ $ (5.8) ​ $ (910.5) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign ​ ​ ​ ​ Accumulated ​ ​ Pension ​ Currency ​ Gain/(Loss) on ​ Other ​ ​ Related ​ Translation ​ Derivative ​ Comprehensive ​ Adjustments Adjustments Instruments Loss Balances at September 30, 2019 ​ $ (302.7) ​ $ (548.7) ​ $ (12.8) ​ $ (864.2) Other comprehensive (loss) income before reclassification ​ (2.0) ​ 28.0 ​ (5.3) ​ 20.7 Amounts reclassified from accumulated other comprehensive loss ​ ​ 29.3 ​ ​ — ​ ​ 8.6 ​ ​ 37.9 Balances at June 30, 2020 ​ $ (275.4) ​ $ (520.7) ​ $ (9.5) ​ $ (805.6)

Reportable Segments (Tables)

Reportable Segments (Tables)	9 Months Ended
	Jun. 30, 2021
Reportable Segments
Summarized financial information concerning the Company's reportable segments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ AECOM ​ ​ ​ ​ ​ ​ ​ Reportable Segments: Americas International Capital Corporate Total ​ ​ ​ (in millions) Three Months Ended June 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 2,618.5 ​ $ 789.3 ​ $ 0.6 ​ $ — ​ $ 3,408.4 ​ Gross profit ​ 160.6 ​ 40.4 ​ 0.6 ​ ​ — ​ ​ 201.6 ​ Equity in earnings of joint ventures ​ 3.2 ​ 5.1 ​ (0.1) ​ ​ — ​ ​ 8.2 ​ General and administrative expenses ​ — ​ — ​ (2.4) ​ ​ (33.9) ​ ​ (36.3) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (13.0) ​ ​ (13.0) ​ Operating income (loss) ​ 163.8 ​ 45.5 ​ (1.9) ​ ​ (46.9) ​ ​ 160.5 ​ Gross profit as a % of revenue ​ 6.1 % 5.1 % — ​ ​ — ​ ​ 5.9 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 2,471.6 ​ $ 717.9 ​ $ 0.2 ​ $ — ​ $ 3,189.7 ​ Gross profit ​ 155.3 ​ 29.6 ​ ​ 0.2 ​ — ​ 185.1 ​ Equity in earnings of joint ventures ​ 5.6 ​ 2.7 ​ ​ 0.3 ​ — ​ 8.6 ​ General and administrative expenses ​ — ​ — ​ ​ (1.1) ​ (53.4) ​ (54.5) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (20.3) ​ ​ (20.3) ​ Operating income (loss) ​ ​ 160.9 ​ ​ 32.3 ​ ​ (0.6) ​ ​ (73.7) ​ ​ 118.9 ​ Gross profit as a % of revenue ​ 6.3 % ​ 4.1 % ​ — ​ ​ — ​ ​ 5.8 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended June 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 7,644.1 ​ $ 2,341.4 ​ $ 1.6 ​ $ — ​ $ 9,987.1 ​ Gross profit ​ ​ 457.3 ​ ​ 122.3 ​ ​ 1.6 ​ ​ — ​ ​ 581.2 ​ Equity in earnings of joint ventures ​ ​ 7.6 ​ ​ 11.1 ​ ​ 4.9 ​ ​ — ​ ​ 23.6 ​ General and administrative expenses ​ ​ — ​ ​ — ​ ​ (5.8) ​ ​ (104.9) ​ ​ (110.7) ​ Restructuring costs ​ ​ — ​ ​ — ​ ​ — ​ ​ (34.8) ​ ​ (34.8) ​ Operating income ​ ​ 464.9 ​ ​ 133.4 ​ ​ 0.7 ​ ​ (139.7) ​ ​ 459.3 ​ Gross profit as a % of revenue ​ ​ 6.0 % ​ 5.2 % ​ — ​ ​ — ​ ​ 5.8 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended June 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 7,399.2 ​ $ 2,270.6 ​ $ 1.2 ​ $ — ​ $ 9,671.0 ​ Gross profit ​ 430.3 ​ 88.2 ​ ​ 1.2 ​ — ​ 519.7 ​ Equity in earnings of joint ventures ​ 17.3 ​ 8.7 ​ ​ 6.0 ​ — ​ 32.0 ​ General and administrative expenses ​ — ​ — ​ ​ (5.3) ​ (133.9) ​ (139.2) ​ Restructuring costs ​ — ​ — ​ ​ — ​ (96.4) ​ (96.4) ​ Operating income ​ 447.6 ​ 96.9 ​ ​ 1.9 ​ (230.3) ​ 316.1 ​ Gross profit as a % of revenue ​ 5.8 % 3.9 % ​ — ​ ​ — ​ 5.4 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reportable Segments: ​ ​ ​ ​ ​ ​ ​ ​ Total assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2021 ​ $ 7,695.0 ​ $ 2,503.8 ​ $ 221.7 ​ $ 1,415.5 September 30, 2020 ​ ​ 8,104.4 ​ ​ 2,454.0 ​ ​ 198.0 ​ ​ 1,625.8

Basis of Presentation (Details)

Basis of Presentation (Details)	9 Months Ended
	Jun. 30, 2021
Minimum
Basis of presentation
Length of fiscal year	364 days
Maximum
Basis of presentation
Length of fiscal year	371 days

New Accounting Pronouncements_2

New Accounting Pronouncements and Changes in Accounting (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Oct. 01, 2020	Sep. 30, 2020	Oct. 01, 2019
New Accounting Pronouncements and Changes in Accounting
(Accumulated deficits) Retained earnings	$ (483,362)		$ 174,248
ASU 2016-02
New Accounting Pronouncements and Changes in Accounting
(Accumulated deficits) Retained earnings				$ (87,800)
ASU 2016-06
New Accounting Pronouncements and Changes in Accounting
(Accumulated deficits) Retained earnings		$ (8,000)

Discontinued Operations, Good_3

Discontinued Operations, Goodwill, and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Sep. 30, 2020
Summary of financial information of the Disposal Group is as follows:
Non-current assets held for sale					$ 54,354
Long-term liabilities held for sale				$ 12,260	79,254
Held for sale
Summary of financial information of the Disposal Group is as follows:
Cash and cash equivalents				5,800	109,900
Receivables and contract assets				70,900	414,300
Other				50,300	38,200
Current assets held for sale				127,000	562,400
Property and equipment, net				52,400	119,800
Other				19,000	181,800
Write-down of assets to fair value less cost to sell				(71,400)	(247,200)
Non-current assets held for sale					54,400
Accounts payable and accrued expenses				76,900	350,400
Contract liabilities				9,200	65,600
Other				4,800	1,600
Current liabilities held for sale				90,900	417,600
Long-term liabilities held for sale				$ 12,300	$ 79,300
Held for sale | Management Services
Summary of financial information of the Disposal Group
Consideration		$ 2,280,000
Favorable working capital price adjustment		122,000
Contingent consideration, prior work claims		$ 120,000
Pre-tax gain (loss)			$ 161,900
Held for sale | Power construction business
Summary of financial information of the Disposal Group
Pre-tax gain (loss)	$ (17,300)
Held for sale | Civil infrastructure construction business
Summary of financial information of the Disposal Group is as follows:
Losses on remeasurement to fair value less cost to sell, net of tax	$ (32,800)

Discontinued Operations, Good_4

Discontinued Operations, Goodwill, and Intangible Assets - Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Discontinued Operations, Goodwill, and Intangible Assets
Revenue	$ 162,900	$ 347,500	$ 606,600	$ 2,661,800
Cost of revenue	159,600	352,500	600,400	2,708,500
Gross (loss) profit	3,300	(5,000)	6,200	(46,700)
Equity in earnings of joint ventures	(3,400)	(11,100)	4,600	(28,000)
(Loss) gain on disposal activities	(6,100)	14,900	(56,222)	161,900
Transaction costs	(700)		(14,300)	(41,400)
Impairment of long-lived assets	(9,400)		(105,194)	(89,288)
Loss from operations	(16,300)	(1,200)	(164,900)	(43,500)
Other income		(200)
Other income				1,600
Interest expense	(100)	(1,500)	(400)	(40,200)
Loss before taxes	(16,400)	(2,900)	(165,300)	(82,100)
Income tax expense (benefit)	(900)	(2,800)	(46,100)	30,600
Net loss from discontinued operations	$ (15,502)	$ (126)	$ (119,168)	$ (112,695)

Discontinued Operations, Good_5

Discontinued Operations, Goodwill, and Intangible Assets - Significant components included in Consolidated Statement of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Discontinued Operations, Goodwill, and Intangible Assets
Property and equipment				$ 4.6
Intangible assets and capitalized debt issuance costs		$ 4.3		35.8
Payments for capital expenditures	$ (2)	$ (2.6)	$ (6.6)	$ (16.8)

Discontinued Operations, Good_6

Discontinued Operations, Goodwill, and Intangible Assets - Segments (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2021USD ($)
Changes in the carrying value of goodwill by reporting segment
Goodwill at the beginning of the period	$ 3,484,221
Foreign Exchange Impact	32,600
Goodwill at the end of the period	3,516,781
Americas
Changes in the carrying value of goodwill by reporting segment
Goodwill at the beginning of the period	2,617,100
Foreign Exchange Impact	14,200
Goodwill at the end of the period	2,631,300
International
Changes in the carrying value of goodwill by reporting segment
Goodwill at the beginning of the period	867,100
Foreign Exchange Impact	18,400
Goodwill at the end of the period	$ 885,500

Discontinued Operations, Good_7

Discontinued Operations, Goodwill, and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2021	Sep. 30, 2020
Identifiable intangible assets with finite useful lives
Intangible Assets, Net	$ 61,666	$ 76,917
Minimum
Identifiable intangible assets with finite useful lives
Amortization Period	1 year
Maximum
Identifiable intangible assets with finite useful lives
Amortization Period	11 years
Backlog and customer relationships
Identifiable intangible assets with finite useful lives
Gross Amount	$ 663,500	662,800
Accumulated Amortization	(601,800)	(585,900)
Intangible Assets, Net	$ 61,700	$ 76,900

Discontinued Operations, Good_8

Discontinued Operations, Goodwill, and Intangible Assets - Amortization Expense (Details) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020
Estimated amortization expense for the succeeding years
2021 (six months remaining)	$ 4,900
2022	19,800
2023	18,800
2024	17,400
2025	800
Intangible Assets, Net	61,666		$ 76,917
Amortization expense	$ 15,900	$ 18,300

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Billions	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
ASU 2014-09
Revenue Recognition
Subcontractor and other direct costs	$ 5.4	$ 5.1

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregated revenues (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue Recognition
Total revenue	$ 3,408.4	$ 3,189.7	$ 9,987.1	$ 9,671
Cost reimbursable
Revenue Recognition
Total revenue	1,309.2	1,369.3	4,041.8	4,252.5
Guaranteed maximum price
Revenue Recognition
Total revenue	1,229.9	829.8	3,443	2,706.4
Fixed price
Revenue Recognition
Total revenue	869.3	990.6	2,502.3	2,712.1
Americas
Revenue Recognition
Total revenue	2,619	2,471.8	7,645.7	7,400.5
Europe, Middle East, Africa
Revenue Recognition
Total revenue	401.3	359.9	1,201.8	1,194.9
Asia Pacific
Revenue Recognition
Total revenue	$ 388.1	$ 358	$ 1,139.6	$ 1,075.6

Revenue Recognition - Performan

Revenue Recognition - Performance obligations (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Revenue, remaining performance obligations
Performance obligation	$ 18,500
Liability recognized	$ 646.6	$ 563.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, remaining performance obligations
Performance Obligation expected timing of satisfaction period	12 months
Performance obligation, percent to be satisfied	55.00%

Revenue Recognition - Accounts

Revenue Recognition - Accounts receivable, net (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Jun. 30, 2021	Sep. 30, 2020
Accounts Receivable-Net
Billed	$ 2,225,000	$ 2,467,300
Contract retentions	541,600	531,300
Total accounts receivable-gross	2,766,600	2,998,600
Allowances for doubtful accounts and credit losses	(97,500)	(77,900)
Total accounts receivable-net	$ 2,669,113	$ 2,920,730
Additional disclosures
Number of clients	No	No
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	$ 170,000
Trade receivables sold, outstanding	$ 243,700	$ 166,600

Joint Ventures and Variable I_3

Joint Ventures and Variable Interest Entities - Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019
Financial Information
Current assets	$ 6,248,493		$ 6,248,493			$ 7,530,366
TOTAL ASSETS	11,963,091		11,963,091			12,998,951
Current liabilities	5,680,031		5,680,031			6,090,454
TOTAL LIABILITIES	9,146,113		9,146,113			9,585,407
Total AECOM equity	2,708,037		2,708,037			3,292,558
Noncontrolling interests	108,941		108,941			120,986
TOTAL STOCKHOLDERS' EQUITY	2,816,978	$ 3,885,869	2,816,978	$ 3,885,869	$ 2,926,700	3,413,544	$ 3,665,523	$ 3,899,350
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	11,963,091		11,963,091			12,998,951
Revenue	3,408,357	$ 3,189,679	9,987,085	9,671,026
Consolidated Joint Ventures
Financial Information
Current assets	530,200		530,200			536,300
Non-current assets	75,300		75,300			77,000
TOTAL ASSETS	605,500		605,500			613,300
Current liabilities	390,200		390,200			409,900
Non-current liabilities	1,500		1,500			1,500
TOTAL LIABILITIES	391,700		391,700			411,400
Total AECOM equity	118,100		118,100			113,900
Noncontrolling interests	95,700		95,700			88,000
TOTAL STOCKHOLDERS' EQUITY	213,800		213,800			201,900
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 605,500		605,500			$ 613,300
Revenue			$ 604,700	$ 602,100

Joint Ventures and Variable I_4

Joint Ventures and Variable Interest Entities - Unconsolidated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019
Financial Information
Current assets	$ 6,248,493		$ 6,248,493			$ 7,530,366
TOTAL ASSETS	11,963,091		11,963,091			12,998,951
Current liabilities	5,680,031		5,680,031			6,090,454
TOTAL LIABILITIES	9,146,113		9,146,113			9,585,407
Joint ventures' equity	2,816,978	$ 3,885,869	2,816,978	$ 3,885,869	$ 2,926,700	3,413,544	$ 3,665,523	$ 3,899,350
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	11,963,091		11,963,091			12,998,951
AECOM's investment in unconsolidated joint ventures	331,994		331,994			297,595
Joint ventures summarized financial information
Revenue	3,408,357	3,189,679	9,987,085	9,671,026
Cost of revenue	3,206,823	3,004,600	9,405,922	9,151,334
Gross profit	201,534	185,079	581,163	519,692
Net income	18,373	$ 94,122	96,673	70,250
Unconsolidated Joint Ventures
Financial Information
Current assets	1,345,700		1,345,700			1,374,300
Non-current assets	546,200		546,200			465,900
TOTAL ASSETS	1,891,900		1,891,900			1,840,200
Current liabilities	912,100		912,100			953,400
Non-current liabilities	57,200		57,200			58,900
TOTAL LIABILITIES	969,300		969,300			1,012,300
Joint ventures' equity	922,600		922,600			827,900
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	1,891,900		1,891,900			1,840,200
AECOM's investment in unconsolidated joint ventures	$ 332,000		332,000			$ 297,600
Joint ventures summarized financial information
Revenue			1,588,400	2,325,700
Cost of revenue			1,539,800	2,281,700
Gross profit			48,600	44,000
Net income			$ 41,800	$ 42,700

Joint Ventures and Variable I_5

Joint Ventures and Variable Interest Entities - Equity in Earnings (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Financial Information
Equity in earnings of joint ventures	$ 8,270	$ 8,573	$ 23,628	$ 32,006
Unconsolidated Joint Ventures
Financial Information
Equity in earnings of joint ventures			23,600	32,000
Unconsolidated Joint Ventures | Pass through joint ventures
Financial Information
Equity in earnings of joint ventures			18,800	26,000
Unconsolidated Joint Ventures | Other joint ventures
Financial Information
Equity in earnings of joint ventures			$ 4,800	$ 6,000

Pension Benefit Obligations (De

Pension Benefit Obligations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2021
United States
Components of net periodic benefit cost:
Interest cost on projected benefit obligation	$ 1.1	$ 1.6	$ 3.2	$ 4.8
Expected return on plan assets	(1.6)	(1.8)	(4.8)	(5.3)
Amortization of prior service cost				0.1
Amortization of net loss	1.4	1.3	4.4	3.7
Curtailment loss recognized		0.5		0.5
Settlement loss recognized	0.1		0.1	0.5
Net periodic benefit cost	1	1.6	2.9	4.3
Change in benefit obligation:
Employer contributions			10.1
Expected remaining scheduled annual employer contributions for the current fiscal year					$ 4.6
International
Components of net periodic benefit cost:
Service costs	0.1	0.1	0.4	0.4
Interest cost on projected benefit obligation	5.5	5.4	16.2	16.7
Expected return on plan assets	(11.1)	(9.1)	(32.6)	(27.9)
Amortization of prior service cost	0.1		0.1
Amortization of net loss	2.4	2.1	6.9	6.4
Settlement loss recognized				0.2
Net periodic benefit cost	$ (3)	$ (1.5)	(9)	$ (4.2)
Change in benefit obligation:
Employer contributions			$ 18.9
Expected remaining scheduled annual employer contributions for the current fiscal year					$ 7.8

Debt (Details)

Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
Debt
Total debt	$ 2,233,900	$ 2,085,000
Less: Current portion of debt and short-term borrowings	(55,200)	(20,900)
Less: Unamortized debt issuance costs	(24,900)	(23,000)
Long-term debt	2,153,812	2,041,136
2014 Credit Agreement
Debt
Total debt	1,156,900	248,500
2024 Senior Notes
Debt
Total debt		797,300
2017 Senior Notes
Debt
Total debt	997,300	997,300
Other Debt
Debt
Total debt	$ 79,700	$ 41,900

Debt - Scheduled Maturities (De

Debt - Scheduled Maturities (Details) - USD ($) $ in Millions	Jun. 30, 2021	Sep. 30, 2020
Debt
2021 (three months remaining)	$ 14.9
2022	48.2
2023	38.1
2024	39.4
2025	34.2
Thereafter	2,059.1
Total debt	$ 2,233.9	$ 2,085

Debt - 2014 Credit Agreement (D

Debt - 2014 Credit Agreement (Details) $ in Millions, $ in Millions

Apr. 13, 2021USD ($)

Feb. 08, 2021USD ($)

Jul. 30, 2020USD ($)

May 01, 2020USD ($)

Jul. 01, 2018

Mar. 13, 2018USD ($)

Oct. 17, 2014USD ($)

Jun. 30, 2021USD ($)

Jun. 30, 2020USD ($)

Jun. 25, 2021USD ($)

Apr. 26, 2021USD ($)

Sep. 30, 2020USD ($)

Oct. 01, 2019

Mar. 13, 2018CAD ($)

Mar. 13, 2018AUD ($)

Mar. 31, 2017

Sep. 29, 2016USD ($)

Oct. 17, 2014CAD ($)

Oct. 17, 2014AUD ($)

Oct. 06, 2014

Debt agreements

Proceeds from secured delayed draw term loan facility

$ 2,848,244,000

$ 4,203,556,000

Term loan A

Debt agreements

Maximum borrowing capacity

$ 185,000,000

Revolving credit facility

Debt agreements

Proceeds from secured delayed draw term loan facility

$ 248,500,000

Revolving credit facility | Euro currency rate

Debt agreements

Interest rate

0.75%

2014 Credit Agreement

Debt agreements

Maximum borrowing capacity

$ 400,000,000

Maximum leverage ratio

4

Subject to increase leverage ratio

4.50

Consolidated leverage ratio

4

2.5

Consolidated interest coverage ratio

3

6.8

2014 Credit Agreement | Base Rate

Debt agreements

Interest rate, basis spread (as a percent)

0.50%

2014 Credit Agreement | LIBOR

Debt agreements

Interest rate, basis spread (as a percent)

1.50%

2014 Credit Agreement | Minimum | Base Rate

Debt agreements

Interest rate, basis spread (as a percent)

0.25%

2014 Credit Agreement | Minimum | Euro currency rate

Debt agreements

Interest rate, basis spread (as a percent)

1.25%

2014 Credit Agreement | Maximum | Base Rate

Debt agreements

Interest rate, basis spread (as a percent)

1.00%

2014 Credit Agreement | Maximum | Euro currency rate

Debt agreements

Interest rate, basis spread (as a percent)

2.00%

2014 Credit Agreement | Term loan A

Debt agreements

Maximum borrowing capacity

$ 510,000,000

$ 510,000,000

$ 215,000,000

$ 500

$ 250

$ 500

$ 250

2014 Credit Agreement | Term loan A | Base Rate | USD

Debt agreements

Interest rate, basis spread (as a percent)

0.50%

2014 Credit Agreement | Term loan A | Euro currency rate

Debt agreements

Interest rate, basis spread (as a percent)

1.50%

2014 Credit Agreement | Term loan B

Debt agreements

Maximum borrowing capacity

$ 600,000,000

600,000,000

2014 Credit Agreement | Term loan B | Base Rate

Debt agreements

Interest rate, basis spread (as a percent)

0.75%

2014 Credit Agreement | Term loan B | Euro currency rate

Debt agreements

Interest rate, basis spread (as a percent)

1.75%

2014 Credit Agreement | Term B facility

Debt agreements

Maximum borrowing capacity

$ 700,000,000

2014 Credit Agreement | Term B facility | Base Rate

Debt agreements

Interest rate, basis spread (as a percent)

0.75%

2014 Credit Agreement | Term B facility | Euro currency rate

Debt agreements

Interest rate, basis spread (as a percent)

1.75%

2014 Credit Agreement | Revolving credit facility

Debt agreements

Maximum borrowing capacity

$ 1,150,000,000

Current borrowing capacity

$ 1,138,800,000

$ 1,331,000,000

Increase in borrowing capacity

$ 1,350,000,000

$ 1,050,000,000

Outstanding letters of credit

$ 11,200,000

$ 19,000,000

2014 Credit Agreement | Revolving credit facility | Base Rate

Debt agreements

Interest rate, basis spread (as a percent)

0.75%

2014 Credit Agreement | Revolving credit facility | Euro currency rate

Debt agreements

Interest rate, basis spread (as a percent)

1.75%

2014 Credit Agreement | Line of credit

Debt agreements

Maximum borrowing capacity

$ 500,000,000

Consolidated leverage ratio

4.5

4

4.5

4.5

4.75

5

2024 Senior Notes

Debt agreements

Cash tender

$ 700,000,000

$ 697,200,000

Interest rate (as a percent)

5.875%

5.875%

5.875%

Debt - 2024 Senior Notes (Detai

Debt - 2024 Senior Notes (Details) - USD ($)	Jun. 25, 2021	Apr. 26, 2021	Apr. 13, 2021	Jul. 21, 2020	Oct. 06, 2014
The 2024 Notes and 2017 Senior Notes | Maximum
Debt
Face amount				$ 639,000,000
2024 Senior Notes
Debt
Face amount		$ 608,300,000		$ 2,700,000	$ 800,000,000
Cash tender		697,200,000	$ 700,000,000
Interest rate (as a percent)	5.875%		5.875%		5.875%
Redemption price (in percent)	115.108%
2024 Senior Notes | Maximum
Debt
Face amount		$ 700,000,000
2024 Senior Notes | Prior to July 15 2024
Debt
Aggregate principal with accrued unpaid interest	$ 217,500,000
2024 Senior Notes | On or after July 15, 2024
Debt
Prepayment premium redemption	$ 117,500,000

Debt - 2017 Senior Notes (Detai

Debt - 2017 Senior Notes (Details) - 2017 Senior Notes - USD ($)	Feb. 21, 2017	Jun. 30, 2021
Debt
Face amount	$ 1,000,000,000
Fair value of debt instrument		$ 1,109,500,000
Interest rate (as a percent)	5.125%
At any time and from time to time prior to December 15, 2026
Debt
Redemption price (in percent)	100.00%

Debt - URS Senior Notes (Detail

Debt - URS Senior Notes (Details) - USD ($) $ in Thousands	Aug. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Oct. 17, 2014
Debt
Repayments of debt		$ 797,252
Proceeds from secured delayed draw term loan facility		2,848,244	$ 4,203,556
Prepayment premium on redemption of unsecured senior notes		$ 117,500
2022 URS Senior Notes
Debt
Remaining principal amount	$ 248,500
Interest rate (as a percent)				5.00%
Redemption price (as percent of principal)	106.835%
Proceeds from secured delayed draw term loan facility	$ 248,500
Prepayment premium on redemption of unsecured senior notes	$ 17,000

Debt - Other Debt and Other Ite

Debt - Other Debt and Other Items (Details) - Other Debt - Standby letter of credit - Unsecured - USD ($) $ in Millions	Jun. 30, 2021	Sep. 30, 2020
Debt
Outstanding letters of credit	$ 489.6	$ 510.1
Current borrowing capacity	$ 443.1

Debt - Effective Interest Rate

Debt - Effective Interest Rate (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt
Effective interest rate including effects of interest rate swap agreements			4.7%	5.2%
Amortization of deferred debt issuance costs	$ 4.6	$ 1.3	$ 9	$ 3.8

Derivative Financial Instrume_3

Derivative Financial Instruments and Fair Value Measurements - Cash Flow Hedges (Details) - USD ($) $ in Millions	Jun. 30, 2021	Sep. 30, 2020
Derivative financial instruments
Fixed Rate (as a percent)	1.349%
Interest rate swap agreements
Derivative financial instruments
Notional Amount	$ 400
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swap agreements | USD
Derivative financial instruments
Notional Amount	$ 200	$ 200
Fixed Rate (as a percent)	2.60%	2.60%

Derivative Financial Instrume_4

Derivative Financial Instruments and Fair Value Measurements - Fair Value Measurements (Details) $ in Millions	9 Months Ended
	Jun. 30, 2021USD ($)
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swap agreements
Derivative financial instruments
Losses recognized in income	$ 0

Share-based Payments (Details)

Share-based Payments (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020
Shares of stock under options
Balance at the beginning of the period (in shares)	0.4	0.1
Granted (in shares)	0	0
Options exercised (in shares)	(0.1)	0
Options forfeited or expired ( in shares)	0	0
Balance at the end of the period (in shares)	0.3	0.1
Vested and expected to vest in the future at the end of the period (in shares)	0.2	0.1
Stock options, Weighted average exercise price
Balance at the beginning of the period (in dollars per share)	$ 36.41	$ 31.62
Granted (in dollars per share)	0	0
Options exercised (in dollars per share)	31.62	0
Cancelled (in dollars per share)	0	0
Balance at the end of the period (in dollars per share)	38.72	31.62
Vested and expected to vest in the future at the end of the period (in dollars per share)	$ 38.72	$ 31.62
Vesting period	3 years
Recognized compensation expense	$ 36.2	$ 37
Unrecognized compensation expense	$ 56.2		$ 50
Performance Earnings Program
Stock options, Weighted average exercise price
Vesting period	3 years
Weighted average grant-date fair value of stock options granted (in dollars per share)	$ 52.76	$ 42.99
Restricted Stock Units
Stock options, Weighted average exercise price
Weighted average grant-date fair value of stock options granted (in dollars per share)	$ 49.21	$ 42.25

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2021	Jun. 30, 2020
Income Taxes
Effective tax rate (as a percent)	25.00%	19.00%	16.60%	14.20%
Federal statutory rate (as a percent)			21.00%	21.00%
Change in uncertain tax positions			$ 25.9
Income tax credits and incentives			39	$ 9
Tax expense related to nondeductible costs			11.5	25.4
Tax benefit due to corporate tax rate change			25.9
Tax expense related to audit settlement			13.2
Tax expense related to Foreign residual income			30.7	22.9
Tax expense related to state income taxes			13.2	$ 21.7
Tax benefit related to the release of a valuation allowance on net operating losses			25.4
Gross book-tax differences from non-U.S. subsidiaries	$ 1,500		$ 1,500

Earnings Per Share (Details)

Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share
Denominator for basic earnings per share	146,109	160,119	148,434	158,667
Potential common shares	2,800	1,700	2,300	2,400
Denominator for diluted earnings per share	148,859	161,835	150,707	161,070

Leases - Components of lease ex

Leases - Components of lease expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020	Oct. 01, 2019
New Accounting Pronouncements and Changes in Accounting
(Accumulated deficits) Retained earnings	$ (483,362)		$ (483,362)		$ 174,248
Operating lease cost
Operating lease cost	46,300	$ 49,300	141,000	$ 144,700
Finance lease cost:
Amortization of right-of-use assets	3,900	4,200	10,300	13,900
Interest on lease liabilities	600	400	1,800	1,400
Variable lease cost	8,500	8,800	27,200	27,100
Total lease cost	$ 59,300	$ 62,700	$ 180,300	$ 187,100
ASU 2016-02
New Accounting Pronouncements and Changes in Accounting
(Accumulated deficits) Retained earnings						$ (87,800)

Leases - Additional balance she

Leases - Additional balance sheet information (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
ASSETS
Operating lease assets	$ 637,313	$ 652,115
Balance Sheet classification of operating lease assets	Operating lease assets	Operating lease assets
Finance lease assets	$ 41,100	$ 29,100
Balance Sheet classification of finance lease assets	PROPERTY AND EQUIPMENT-NET	PROPERTY AND EQUIPMENT-NET
Total lease assets	$ 678,400	$ 681,200
Current:
Operating lease liabilities	$ 162,800	$ 168,400
Balance Sheet classification of operating lease liabilities	Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Finance lease liabilities	$ 14,100	$ 9,800
Balance Sheet classification of finance lease liabilities	Current portion of long-term debt	Current portion of long-term debt
Total current lease liabilities	$ 176,900	$ 178,200
Operating lease liabilities	$ 711,494	$ 745,287
Balance Sheet classification of operating lease liabilities	Operating lease liabilities	Operating lease liabilities
Finance lease liabilities	$ 30,500	$ 22,000
Balance Sheet classification of finance lease liabilities	LONG-TERM DEBT	LONG-TERM DEBT
Total non-current lease liabilities	$ 742,000	$ 767,300
Weighted average remaining lease term (in years):
Operating leases	0 years	7 years 3 months 18 days
Finance leases	0 years	3 years 3 months 18 days
Weighted average discount rates:
Operating leases	4.40%	4.60%
Finance leases	4.60%	4.70%

Leases - Additional cash flow i

Leases - Additional cash flow information (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 165.9	$ 168.3
Operating cash flows from finance leases	1.5	1.3
Financing cash flows from finance leases	10.1	11.9
Right-of-use assets obtained in exchange for new operating leases	77.3	90.8
Right-of-use assets obtained in exchange for new finance leases	$ 22.2	$ 17.5

Leases - Total remaining lease

Leases - Total remaining lease payments under the Company's operating lease (Details) $ in Millions	Jun. 30, 2021USD ($)
Amounts payable under non-cancelable operating lease commitments
2021 (three months remaining)	$ 53
2022	188.6
2023	155
2024	132.9
2025	113
Thereafter	376.1
Total lease payments	1,018.6
Less: Amounts representing interest	(144.3)
Total lease liabilities	$ 874.3

Leases - Total remaining leas_2

Leases - Total remaining lease payments under the Company's Finance lease (Details) $ in Millions	Jun. 30, 2021USD ($)
Leases
2021 (three months remaining)	$ 3.9
2022	15.6
2023	13.4
2024	9.8
2025	4.5
Thereafter	0.8
Total lease payments	48
Less: Amounts representing interest	(3.4)
Total lease liabilities	$ 44.6

Other Financial Information (De

Other Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020
Accrued expenses and other current liabilities
Accrued salaries and benefits	$ 702,200		$ 702,200		$ 675,700
Accrued contract costs	1,252,300		1,252,300		1,137,500
Other accrued expenses	380,600		380,600		436,500
Total accrued expenses	2,335,077		2,335,077		2,249,704
Restructuring costs	12,971	$ 20,300	34,755	$ 96,438
Accrued restructuring expenses	6,500		6,500
Minimum
Accrued expenses and other current liabilities
Restructuring and Related Cost, Expected Cost	40,000		40,000
Maximum
Accrued expenses and other current liabilities
Restructuring and Related Cost, Expected Cost	50,000		50,000
Personnel and other costs
Accrued expenses and other current liabilities
Restructuring costs			25,800	83,500
Real estate costs
Accrued expenses and other current liabilities
Restructuring costs			9,000	$ 12,900
Professional liability accrual
Accrued expenses and other current liabilities
Accrued contract costs	$ 800,400		$ 800,400		$ 625,900

Reclassifications out of Accu_3

Reclassifications out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accumulated balances
Balance at the beginning of the period	$ (895,700)	$ (881,600)	$ (918,674)	$ (864,200)
Other comprehensive (loss) income before reclassification	(18,700)	72,300	(3,500)	20,700
Amounts reclassified from accumulated other comprehensive loss	3,900	3,700	11,700	37,900
Balance at the end of the period	(910,532)	(805,600)	(910,532)	(805,600)
Pension Related Adjustments
Accumulated balances
Balance at the beginning of the period	(353,500)	(280,000)	(342,800)	(302,700)
Other comprehensive (loss) income before reclassification	200	1,700	(16,500)	(2,000)
Amounts reclassified from accumulated other comprehensive loss	3,000	2,900	9,000	29,300
Balance at the end of the period	(350,300)	(275,400)	(350,300)	(275,400)
Foreign Currency Translation Adjustments
Accumulated balances
Balance at the beginning of the period	(535,600)	(592,100)	(567,300)	(548,700)
Other comprehensive (loss) income before reclassification	(18,800)	71,400	12,900	28,000
Balance at the end of the period	(554,400)	(520,700)	(554,400)	(520,700)
Gain/(Loss) on Derivative Instruments
Accumulated balances
Balance at the beginning of the period	(6,600)	(9,500)	(8,600)	(12,800)
Other comprehensive (loss) income before reclassification	(100)	(800)	100	(5,300)
Amounts reclassified from accumulated other comprehensive loss	900	800	2,700	8,600
Balance at the end of the period	$ (5,800)	$ (9,500)	$ (5,800)	$ (9,500)

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	Jan. 31, 2020	Dec. 31, 2019	Apr. 30, 2019	Mar. 31, 2019	Jun. 30, 2021	Dec. 06, 2019	Dec. 31, 2014
New York
Commitments and Contingencies
Contingency liability					$ 146
Percentage of claim recoveries due to seller	90.00%
Percentage of claim recoveries due to purchaser	10.00%
Montana
Commitments and Contingencies
Damages sought			$ 132	$ 79
Damages sought, counter party		$ 93
Department of Energy | New York | Minimum
Commitments and Contingencies
Contingency liability					106
Department of Energy | New York | Maximum
Commitments and Contingencies
Contingency liability					146
Fund investment capital commitments
Commitments and Contingencies
Commitment					$ 20.3
Commitment period					8 years
Standby letters of credit
Commitments and Contingencies
Contingency liability					$ 500.2
Surety Bond
Commitments and Contingencies
Contingency liability					3,800
Collectibility of Receivables
Commitments and Contingencies
Unapproved change orders							$ 103
Collectibility of Receivables | New York
Commitments and Contingencies
Unapproved change orders						$ 60.4
Collectibility of Receivables | New York | Minimum
Commitments and Contingencies
Damages sought					148.5
Collectibility of Receivables | New York | Maximum
Commitments and Contingencies
Damages sought					329.4
Collectibility of Receivables | Montana
Commitments and Contingencies
Unapproved change orders					90
Damages sought					$ 144

Reportable Segments (Details)

Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020
Summarized financial information concerning the Company's reportable segments
Revenue	$ 3,408,357	$ 3,189,679	$ 9,987,085	$ 9,671,026
Gross profit	201,534	185,079	581,163	519,692
Equity in earnings of joint ventures	8,270	8,573	23,628	32,006
General and administrative expenses	(36,340)	(54,482)	(110,707)	(139,133)
Restructuring costs	(12,971)	(20,300)	(34,755)	(96,438)
Operating income	160,493	118,870	459,329	316,127
Segment assets	11,963,091		11,963,091		$ 12,998,951
Total
Summarized financial information concerning the Company's reportable segments
Revenue	3,408,400	3,189,700	9,987,100	9,671,000
Gross profit	201,600	185,100	581,200	519,700
Equity in earnings of joint ventures	8,200	8,600	23,600	32,000
General and administrative expenses	(36,300)	(54,500)	(110,700)	(139,200)
Restructuring costs	(13,000)	(20,300)	(34,800)	(96,400)
Operating income	$ 160,500	$ 118,900	$ 459,300	$ 316,100
Gross profit as a % of revenue	5.90%	5.80%	5.80%	5.40%
Corporate
Summarized financial information concerning the Company's reportable segments
General and administrative expenses	$ (33,900)	$ (53,400)	$ (104,900)	$ (133,900)
Restructuring costs	(13,000)	(20,300)	(34,800)	(96,400)
Operating income	(46,900)	(73,700)	(139,700)	(230,300)
Segment assets	1,415,500		1,415,500		1,625,800
Americas
Summarized financial information concerning the Company's reportable segments
Revenue	2,618,500	2,471,600	7,644,100	7,399,200
Gross profit	160,600	155,300	457,300	430,300
Equity in earnings of joint ventures	3,200	5,600	7,600	17,300
Operating income	$ 163,800	$ 160,900	$ 464,900	$ 447,600
Gross profit as a % of revenue	6.10%	6.30%	6.00%	5.80%
Segment assets	$ 7,695,000		$ 7,695,000		8,104,400
International
Summarized financial information concerning the Company's reportable segments
Revenue	789,300	$ 717,900	2,341,400	$ 2,270,600
Gross profit	40,400	29,600	122,300	88,200
Equity in earnings of joint ventures	5,100	2,700	11,100	8,700
Operating income	$ 45,500	$ 32,300	$ 133,400	$ 96,900
Gross profit as a % of revenue	5.10%	4.10%	5.20%	3.90%
Segment assets	$ 2,503,800		$ 2,503,800		2,454,000
AECOM Capital
Summarized financial information concerning the Company's reportable segments
Revenue	600	$ 200	1,600	$ 1,200
Gross profit	600	200	1,600	1,200
Equity in earnings of joint ventures	(100)	300	4,900	6,000
General and administrative expenses	(2,400)	(1,100)	(5,800)	(5,300)
Operating income	(1,900)	$ (600)	700	$ 1,900
Segment assets	$ 221,700		$ 221,700		$ 198,000