AMERICAN TOWER CORP /MA/

(c)Insider Trading Arrangements and Policies

Rule 10b5-1 Plans

Olivier Puech, our Executive Vice President and President, International, entered into a pre-arranged stock trading plan on April 30, 2025. Mr. Puech’s plan provides for the potential sale of up to 29,167 shares of our common stock, a number of shares of our common stock to be determined that will be purchased under the ESPP, and a number of shares of our common stock to be determined that may be earned in connection with the grant of the 2023 PSUs (as further discussed in note 9 to our consolidated and condensed consolidated financial statements included in this Quarterly Report) between August 1, 2025 and March 15, 2026.

Steven O. Vondran, our President and Chief Executive Officer, entered into a pre-arranged stock trading plan on May 6, 2025. Mr. Vondran’s plan provides for the potential exercise of vested stock options and the associated sale of up to 33,482 shares of our common stock, including such exercised options, between August 5, 2025 and March 10, 2026.

Rodney M. Smith, our Executive Vice President, Chief Financial Officer and Treasurer, entered into a pre-arranged stock trading plan on May 22, 2025. Mr. Smith’s plan provides for the potential exercise of vested stock options and the sale of up to 34,341 shares of our common stock, including such exercised options, between August 21, 2025 and February 20, 2026.

Each of these trading plans was entered into during an open insider trading window and is intended to satisfy the affirmative defense of Rule 10b5-1 under the Exchange Act and our policies regarding transactions in our securities. Generally, these trading plans pre-establish the amounts, prices and dates of future purchases or sales of our stock, including shares issued upon the exercise or vesting of equity awards. Under these trading plans, the individual officer relinquishes control over the transactions once the trading plan is put into place. Accordingly, sales under these plans may occur at any time, including possibly before, simultaneously with, or immediately after, significant Company events.