MasTec美股招股说明书(2026-08-10版)

5.850% Senior Notes due 2036 We are offering $650,000,000 aggregate principal amount of our 5.850% Senior Notes due 2036 (the “notes”). The notes will mature on September 30,2036. We will pay interest on the notes semi-annually in arrears on March 30 and September 30 of each year, commencing March 30, 2027. The notes will be general senior unsecured obligations of MasTec, Inc. (“MasTec”) and will rank equal in right of payment with all existing and futuresenior unsecured indebtedness of MasTec. The notes will be effectively subordinated to all secured indebtedness of MasTec, to the extent of the value ofthe assets securing such indebtedness. The notes will rank senior in right of payment to any future subordinated indebtedness of MasTec. The notes willnot be guaranteed by any of MasTec’s subsidiaries and will therefore be structurally subordinated to all of the obligations of the subsidiaries of MasTec,including trade payables. We may redeem all or a portion of the notes at our option at any time or from time to time at the applicable redemption price in the circumstancesdescribed in this prospectus supplement. See “Description of Notes—Optional Redemption.” We will be required to offer to purchase the notes upon the occurrence of a Change of Control Triggering Event (as defined herein) at a price equal to101% of the principal amount of the notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the date of purchase. See“Description of Notes—Purchase upon a Change of Control Triggering Event.” Investing in the notes involves certain risks. See “Risk Factors” beginning on page S-6 of this prospectus supplementand on page 3 of the accompanying prospectus. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities ordetermined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is acriminal offense. (1)Plus accrued interest, if any, from August 17, 2026. The notes are a new issue of securities with no established trading market. We do not intend to apply for listing of the notes on any securities exchangeor for inclusion of the notes on any automated dealer quotation system. We expect that delivery of the notes, in book-entry form only through thefacilities of The Depository Trust Company for the accounts of its participants, including Euroclear Bank SA/NV, as operator of the Euroclear System,and Clearstream Banking, S.A., will be made on or about August17, 2026. WellsFargoSecurities KeyBanc Capital Markets Neither we nor the underwriters have authorized anyone to provide you with any information other than the information contained in, orincorporated by reference in, this prospectus supplement, the accompanying prospectus and any free writing prospectus prepared by or onbehalf of us. We and the underwriters take no responsibility for, and can provide no assurance as to the reliability of, any other informationthat others may give you. This prospectus supplement may be used only for the purpose for which it has been prepared. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. Youshould not assume that the information appearing in this prospectus supplement, the accompanying prospectus or any document incorporatedby reference is accurate as of any date other than the date of the applicable document. Our business, financial condition, results of operationsand prospects may have changed since the relevant date. Neither this prospectus supplement nor the accompanying prospectus constitutes anoffer or an invitation on our behalf or on behalf of the underwriters to subscribe for or purchase any of the securities, and may not be used foror in connection with an offer or solicitation by anyone, in any jurisdiction in which such an offer or solicitation is not authorized or to anyperson to whom it is unlawful to make such an offer or solicitation. We expect that delivery of the notes will be made to investors on or about August 17, 2026, which will be the seventh business day following the date ofthis prospectus supplement (such settlement being referred to as “T+7”). Under Rule 15c6-1 under the Securities Exchange Act of 1934, as amended(the “Exchange Act”), trades in the secondary market are required to settle in one business day, unless the parties to any such trade expressly agreeotherwise. Accordingly, purchasers who wish to trade notes prior to the first business day preceding the delivery of the notes hereunder will be required,by virtue of the fact that the notes initially settle in T+7, to specify an alternate settlement arrangement at the time of any such trade to prevent a failedsettlement. Purchasers of the notes who wish to trade the notes prior to the first business day preceding the date of delivery hereunder should consulttheir ad