X0508 4 2025-12-15 0 0000868857 AECOM ACM 0001805823 Gan David Y. C/O AECOM 13355 NOEL RD, SUITE 400 DALLAS TX 75240 0 1 0 0 CHIEF LEGAL OFFICER 1 Common Stock 2025-12-15 4 M 0 5976 0 A 46991 D Common Stock 2025-12-15 4 A 0 6534 0 A 53525 D Common Stock 2025-12-15 4 A 0 14056 0 A 67581 D Common Stock 2025-12-15 4 F 0 10530 97.96 D 57051 D Common Stock 2025-12-15 4 S 0 6000 98.85 D 51051 D Common Stock 2025-12-17 4 S 0 9502 97.01 D 41549 D Common Stock 576.55 I by Merrill Lynch under AECOM Retirement & Savings Plan (RSP) Restricted Stock Units 2025-12-15 4 M 0 5976 D Common Stock 5976 0 D Each restricted stock unit represents a contingent right to receive, upon vesting, one share of the Issuer's common stock. These restricted stock units were granted on December 15, 2022, and vested in full on December 15, 2025. Represents annual grant of restricted stock units. Each restricted stock unit represents a contingent right to receive, upon vesting, one share of the Issuer's common stock in accordance with the Issuer's 2020 Stock Incentive Plan. The restricted stock units vest in full on December 15, 2028, subject to continued service through the vesting date. Represents shares acquired pursuant to AECOM's Performance Earnings Program under the 2020 Stock Incentive Plan. Represents shares of common stock withheld by the Issuer to satisfy certain tax withholding obligations in connection with the vesting of the restricted stock units and shares acquired under the Performance Earnings Program. The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 15, 2025. Matt Benson, Attorney-in-Fact for David Gan 2025-12-17