MasTec美股招股说明书(2026-07-31版)

Common Stock The shares of common stock described in this prospectus supplement are being offered for sale from time to time by the selling shareholders namedherein. The selling shareholders, or their permitted transferees or other successors-in-interest may offer the shares from time to time through public orprivate transactions at prevailing market prices, at prices related to prevailing market prices or at privately negotiated prices. We will not receive anyproceeds from the selling shareholders’ sale of such shares. Our common stock is listed on the New York Stock Exchange under the symbol “MTZ.” On July28, 2026, the last reported sale price of our commonstock on the New York Stock Exchange was $312.44 per share. Investing in our common stock involves risks. See “Risk Factors” on page S-3 of this prospectus supplement and thedocuments we incorporate by reference, including our most recent Annual Report on Form 10-K. Neither the Securities and Exchange Commission (the “SEC” or the “Commission”) nor any state securities commission has approved ordisapproved of these securities or determined if this prospectus supplement or accompanying prospectus is truthful or complete. Anyrepresentation to the contrary is a criminal offense. July31, 2026 You should rely only on the information contained in, or incorporated by reference in, this prospectus supplement and the accompanyingprospectus. We have not authorized anyone to provide you with different or additional information. If anyone provides you with different oradditional information, you should not rely on it. 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 in this prospectus supplement or the accompanying prospectus and thedocuments incorporated by reference herein and therein is accurate as of any date other than their respective dates. Our business, financialcondition, liquidity, results of operations and prospects may have changed since those dates. Table of Contents TABLE OF CONTENTS Prospectus Supplement About This Prospectus SupplementForward-Looking StatementsSummaryRisk FactorsUse of ProceedsSelling ShareholdersPlan of DistributionLegal Matters Prospectus Important Information About This ProspectusForward-Looking InformationRisk FactorsOur CompanyUse of ProceedsDescription of Common and Preferred Stock Description of Depositary Shares Plan of Distribution Legal Matters Where You Can Find More Information Incorporation of Certain Documents by Reference Unless we have indicated, or the context otherwise requires, references in this prospectus supplement to “MasTec,” the “Company,” “we,” “us,” “our,”or similar terms are to MasTec, Inc. and its subsidiaries. Table of Contents ABOUT THIS PROSPECTUS SUPPLEMENT We are providing information to you about this offering in two parts. The first part is this prospectus supplement, which provides the specific detailsregarding this offering. The second part is the accompanying base prospectus, which provides general information. Generally, when we refer to this“prospectus,” we are referring to both documents combined. Some of the information in the base prospectus may not apply to this offering. Ifinformation in the prospectus supplement is inconsistent with the accompanying base prospectus, you should rely on this prospectus supplement. FORWARD-LOOKING STATEMENTS Forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 are included in this prospectus supplement andthe accompanying prospectus and the information incorporated by reference herein and therein. Forward-looking statements can be identified by the factthat they do not relate strictly to historical or current facts. The use of words such as “anticipate,” “estimate,” “could,” “should,” “may,” “might,” “plan,”“seek,” “expect,” “believe,” “intend,” “target,” “will,” “project,” “forecast,” “continue” and variations of these words and negatives thereof and similarexpressions are intended to identify forward-looking statements. They also include statements regarding: •our future growth and profitability;•our competitive strengths; and•our business strategy and the trends we anticipate in the industries and economies in which we operate. These forward-looking statements are based on currently available operating, financial, economic and other information, and are subject to a number ofsignificant risks and uncertainties. A variety of factors, many of which are beyond our control, could cause actual future results to differ materially fromthose projected in the forward-looking statements. Specific factors that might cause such a difference include, but are not limited to: •our ability to manage projects effectively and in accordance with our estimates, as well as our ability to accurately estimate the costsassociated with our fixed price and other contracts, including any mate