美国电塔美股招股说明书(2025-12-03版)

$850,000,000 4.700% Senior Notes due 2032 We are offering $850,000,000 of 4.700% Senior Notes due 2032 (the “notes”). We will pay cash interest on the notes on June 15 and December15 of each year, beginning on June 15,2026. The notes will mature on December 15, 2032.The notes will be general, unsecured obligations of American Tower Corporation and will rank equally in right of payment with all other senior unsecured debt obligations ofAmerican Tower Corporation. The notes will be structurally subordinated to all existing and future indebtedness and other obligations of our subsidiaries.We may redeem the notes at any time and from time to time, in whole or in part, in cash at the applicable redemption prices described under the heading “Description of Notes—Optional Redemption.”The notes will not be listed on any securities exchange. Currently, there is no public market for the notes. Investing in the notes involves risks. See “Risk Factors” beginning on page S-8 and those described as risk factors in Part I,Item 1A, of our Annual Report on Form 10-K for the year ended December31, 2024 (the “2024 Annual Report”) incorporatedherein by reference. (1)Plus accrued interest, if any, from December 5, 2025, if settlement occurs after that date.(2)Before reimbursement of a portion of our expenses in connection with the notes offering, which the underwriters have agreed to make to us. Neither the Securities and Exchange Commission (the “SEC”) nor any state securities commission has approved or disapproved of these securities or determined if this prospectussupplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense. The underwriters expect to deliver the notes in book-entry form only through the facilities of The Depository Trust Company for the accounts of its participants, including ClearstreamBanking, S.A. (“Clearstream”), and Euroclear Bank S.A./N.V. (the “Euroclear Operator”), as operator of the Euroclear System (“Euroclear”), against payment on December 5, 2025, which isthe third business day following the date of this prospectus supplement (this settlement cycle being referred to as “T+3”). Under Rule15c6-1 of the Securities Exchange Act of 1934, asamended (the “Exchange Act”), trades in the secondary market generally are required to settle in one business day, unless the parties to the trade expressly agree otherwise. Accordingly,purchasers who wish to trade the notes on the date of this prospectus supplement or the following business day will be required, by virtue of the fact that the notes initially will settle in T+3,to specify an alternate settlement cycle at the time of any such trade to prevent a failed settlement and should consult their own advisors. Table of Contents TABLE OF CONTENTSProspectus Supplement About this Prospectus SupplementNote Regarding Forward-Looking StatementsMarket and Industry DataProspectus Supplement SummaryRisk FactorsUse of ProceedsCapitalizationDescription of NotesUnderwritingLegal MattersExpertsWhere You Can Find More Information Prospectus Table of Contents We are responsible for the information contained and incorporated by reference in this prospectus supplement and the accompanyingprospectus. We have not, and the underwriters have not, authorized anyone to give you any other information, and we take no responsibility forany other information that others may give you. We are not making an offer to sell these securities in any jurisdiction where the offer or sale isnot permitted. You should not assume that the information contained or incorporated by reference in this prospectus supplement or theaccompanying prospectus is accurate as of any date other than the date of the document containing the information. ABOUT THIS PROSPECTUS SUPPLEMENT This document consists of two parts. The first part is this prospectus supplement, which describes the specific terms of this offering. The secondpart is the accompanying prospectus, which describes more general information, some of which may not apply to this offering. You should read both thisprospectus supplement and the accompanying prospectus, together with the documents incorporated by reference and the additional informationdescribed below under the heading “Where You Can Find More Information.” If the description of the offering varies between this prospectus supplement and the accompanying prospectus, you should rely on the information Any statement made in this prospectus supplement or in a document incorporated or deemed to be incorporated by reference in this prospectussupplement will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in thisprospectus supplement or in any other subsequently filed document that is also incorporated or deemed to be incorporated by reference in thisprospectus supplement modifies or supersedes that statement. Any statement so modified or superse