<SEC-DOCUMENT>0000015615-25-000110.txt : 20250922
<SEC-HEADER>0000015615-25-000110.hdr.sgml : 20250922
<ACCEPTANCE-DATETIME>20250922163155
ACCESSION NUMBER:		0000015615-25-000110
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250918
FILED AS OF DATE:		20250922
DATE AS OF CHANGE:		20250922

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Apple Robert E
		CENTRAL INDEX KEY:			0001382697
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08106
		FILM NUMBER:		251330483

	MAIL ADDRESS:	
		STREET 1:		800 S DOUGLAS ROAD
		STREET 2:		12TH FLOOR
		CITY:			CORAL GABLES
		STATE:			FL
		ZIP:			33134

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MASTEC INC
		CENTRAL INDEX KEY:			0000015615
		STANDARD INDUSTRIAL CLASSIFICATION:	WATER, SEWER, PIPELINE, COMM AND POWER LINE CONSTRUCTION [1623]
		ORGANIZATION NAME:           	05 Real Estate & Construction
		EIN:				650829355
		STATE OF INCORPORATION:			FL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		800 S. DOUGLAS ROAD
		STREET 2:		10TH FLOOR
		CITY:			CORAL GABLES
		STATE:			FL
		ZIP:			33134
		BUSINESS PHONE:		3055991800

	MAIL ADDRESS:	
		STREET 1:		800 S. DOUGLAS ROAD
		STREET 2:		10TH FLOOR
		CITY:			CORAL GABLES
		STATE:			FL
		ZIP:			33134

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BURNUP & SIMS INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1758573111.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-09-18</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000015615</issuerCik>
        <issuerName>MASTEC INC</issuerName>
        <issuerTradingSymbol>MTZ</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001382697</rptOwnerCik>
            <rptOwnerName>Apple Robert E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>800 S DOUGLAS ROAD, 12TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CORAL GABLES</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33134</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>COO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>1</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-09-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>9900</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>200.43</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>184349</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-09-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>100</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>201.06</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>184249</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12068.3991</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k) Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Mr. Apple, 75 years old, is systematically reducing his portfolio concentration in MasTec shares through a 10b5-1 plan, which has more than one pricing tranche. These 10,000 shares sold under the plan represent 5.15% of the shares directly owned by Mr. Apple.</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted average price. These shares were sold in 47 separate transactions, with prices ranging from $200.03 to $201.00 for an average weighted sales price of $200.43. The reporting person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission upon request, full information regarding the number of shares sold in each transaction.</footnote>
        <footnote id="F3">Includes 85,750 shares of MasTec common stock contributed by the reporting person to The Apple Family Trust of which the reporting person and his wife are trustees and beneficiaries.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>\s\ Alberto de Cardenas For: Robert Apple</signatureName>
        <signatureDate>2025-09-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
