美国电塔美股招股说明书(2026-05-19版)

The notes will be general, unsecured obligations of American Tower Corporation and will rank equally in right of payment with all othersenior unsecured debt obligations of American Tower Corporation. The notes will be structurally subordinated to all existing and future indebtednessand 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 underthe heading “Description of Notes—Optional Redemption.” In addition, we may redeem the notes at any time in whole, but not in part, in cash at aredemption price of 100% of the principal amount, together with accrued and unpaid interest on the notes to, but not including, the date fixed forredemption at our option in the event of certain developments affecting U.S. taxation as described under “Description of Notes—Redemption forTax Reasons.” We intend to apply to list the notes on the New York Stock Exchange (the “NYSE”). The listing application will be subject to approval by theNYSE. We currently expect trading in the notes on the NYSE to begin within 30 days after the initial issuance of the notes. If such a listing isobtained, we have no obligation to maintain it, and we may delist the notes at any time. Currently, there is no public market for the notes. Investing in the notes involves risks. See “Risk Factors” beginning on page S-6 and those described as riskfactors in Part I, Item 1A of our Annual Report on Form 10-K for the year ended December31, 2025 (the “2025Annual Report”) incorporated herein by reference. (1)Plus accrued interest, if any, from, 2026, if settlement occurs after that date. Neither the Securities and Exchange Commission (the “SEC”) nor any state securities commission has approved or disapproved of thesesecurities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary isa criminal offense. This preliminary prospectus supplement relates to an effective registration statement under the Securities Act of 1933, as amended, but is not completeand may be changed.The underwriters expect to deliver the notes in book-entry form only through the facilities of Clearstream Banking, S.A. (“Clearstream”), andEuroclear Bank S.A./N.V. (the “Euroclear Operator”), as operator of the Euroclear System (“Euroclear”), against payment on, 2026, whichis the fifth business day following the date of this prospectus supplement (this settlement cycle being referred to as “T+5”). Under Rule 15c6-1 ofthe Securities Exchange Act of 1934, as amended (the “Exchange Act”), trades in the secondary market generally are required to settle in onebusiness day, unless the parties to the trade expressly agree otherwise. Accordingly, purchasers who wish to trade the notes more than one businessday prior to their date of delivery will be required, by virtue of the fact that the notes initially will settle in T+5, to specify an alternate settlementcycle 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 ProceedsCurrency ConversionCapitalizationDescription of NotesMaterial U.S. Federal Income Tax ConsiderationsCertain European Union Tax ConsiderationsUnderwritingLegal MattersExpertsWhere You Can Find More Information Prospectus 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. Table of Contents 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 informationin this prospectus supplement. Any statement made in this prosp