X0306 4 2020-03-10 0001053507 AMERICAN TOWER CORP /MA/ AMT 0001411313 Sharma Amit 116 HUNTINGTON AVENUE BOSTON MA 02116 0 1 0 0 EVP, Asia Common Stock 2020-03-10 4 A 0 7546 0 A 248926 D Common Stock 2020-03-10 4 F 0 14903 243.87 D 234023 D Common Stock 2020-03-11 4 F 0 881 232.90 D 233142 D These restricted stock units ("RSUs") were granted pursuant to the 2007 Equity Incentive Plan, as amended (the "Plan") and vest in 25% cumulative annual increments beginning March 10, 2021. Each RSU respresents a contingent right to receive one share of Common Stock. Shares delivered to the issuer for the payment of withholding taxes in connection with the vesting of RSUs and performance-based restricted stock units previously granted under the Plan. Shares delivered to the issuer for the payment of withholding taxes in connection with the vesting of RSUs previously granted under the Plan. /s/ Mneesha O. Nahata, as attorney-in-fact 2020-03-12