<SEC-DOCUMENT>0001739445-21-000137.txt : 20211001
<SEC-HEADER>0001739445-21-000137.hdr.sgml : 20211001
<ACCEPTANCE-DATETIME>20211001125828
ACCESSION NUMBER:		0001739445-21-000137
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210930
FILED AS OF DATE:		20211001
DATE AS OF CHANGE:		20211001

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LINDSAY JOHN W
		CENTRAL INDEX KEY:			0001219880

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38494
		FILM NUMBER:		211297999

	MAIL ADDRESS:	
		STREET 1:		1437 S. BOULDER AVE.
		STREET 2:		SUITE 1400
		CITY:			TULSA
		STATE:			OK
		ZIP:			74119

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Arcosa, Inc.
		CENTRAL INDEX KEY:			0001739445
		STANDARD INDUSTRIAL CLASSIFICATION:	FABRICATED STRUCTURAL METAL PRODUCTS [3440]
		IRS NUMBER:				825339416
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		500 N. AKARD SREET
		STREET 2:		SUITE 400
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75201
		BUSINESS PHONE:		972-942-6500

	MAIL ADDRESS:	
		STREET 1:		500 N. AKARD SREET
		STREET 2:		SUITE 400
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75201
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_163310749357930.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-09-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001739445</issuerCik>
        <issuerName>Arcosa, Inc.</issuerName>
        <issuerTradingSymbol>ACA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001219880</rptOwnerCik>
            <rptOwnerName>LINDSAY JOHN W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 N AKARD ST. SUITE 400</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Arcosa Phantom Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.0</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-09-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>554</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>50.17</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>554.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6749</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The Arcosa Phantom Stock Units were accrued under the Arcosa, Inc. Deferred Plan for Director Fees. Each share of phantom stock units is the economic equivalent of one share of common stock. The phantom stock units settle in cash upon the reporting person's termination of services with Arcosa.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Mark Elmore, by Power of Attorney</signatureName>
        <signatureDate>2021-10-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
