American Tower Corporation

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. (d) On September 17, 2026, the Board of Directors (the “Board”) of American Tower Corporation (the “Company”) elected Kristen M. Ludgate as a director and member of its Compensation and Human Capital Committee, effective immediately. In accordance with the Company’s Amended and Restated By-Laws, Ms. Ludgate will serve as a director until the Company’s 2027 Annual Meeting of Stockholders and until her successor is duly elected and qualified. Ms. Ludgate most recently served as Chief People Officer of HP Inc., a global technology company, from 2021 to 2025, where she led culture, talent and organizational strategies to accelerate the company's transformation and worked closely with HP's chief executive officer and board of directors on succession, compensation and corporate strategy. Prior to HP, Ms. Ludgate spent over 15 years at 3M Company, where she held two c-suite roles, as Executive Vice President and Chief Human Resources Officer and as Senior Vice President, Communications and Enterprise Services, as well as executive leadership roles in Legal, Compliance and Human Resources. Ms. Ludgate has extensive experience in governance, risk management, talent strategy and enterprise transformation, advising chief executive officers and boards of directors on strategic and operational matters. Ms. Ludgate currently serves on the board of directors of Associated Banc-Corp (Associated Bank), where she chairs the Compensation and Benefits committee, and previously served on the board of directors of OpenText Corporation. For her service on the Board, Ms. Ludgate will receive the Company’s standard compensation for non-employee directors. A copy of the Press Release (“Press Release”) announcing the appointment of Ms. Ludgate to the Board is is filed herewith as Exhibit 99.1.

Item 8.01 Other Events. On September 18, 2026, the Company issued a press release announcing that the Board declared a cash distribution of $1.79 per share on shares of the Company’s common stock, payable on October 20, 2026 to the stockholders of record at the close of business on September 30, 2026. A copy of the Press Release is filed herewith as Exhibit 99.1.