<SEC-DOCUMENT>0001140361-14-004051.txt : 20140131
<SEC-HEADER>0001140361-14-004051.hdr.sgml : 20140131
<ACCEPTANCE-DATETIME>20140131180545
ACCESSION NUMBER:		0001140361-14-004051
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20130701
FILED AS OF DATE:		20140131
DATE AS OF CHANGE:		20140131

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SM Energy Co
		CENTRAL INDEX KEY:			0000893538
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				410518430
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1775 SHERMAN STREET
		STREET 2:		SUITE 1200
		CITY:			DENVER
		STATE:			CO
		ZIP:			80203
		BUSINESS PHONE:		303-861-8140

	MAIL ADDRESS:	
		STREET 1:		1775 SHERMAN STREET
		STREET 2:		SUITE 1200
		CITY:			DENVER
		STATE:			CO
		ZIP:			80203

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ST MARY LAND & EXPLORATION CO
		DATE OF NAME CHANGE:	19940228

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BEST ANTHONY JAMES
		CENTRAL INDEX KEY:			0001364843

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31539
		FILM NUMBER:		14566050

	MAIL ADDRESS:	
		STREET 1:		1776 LINCOLN STREET
		STREET 2:		SUITE 700
		CITY:			DENVER
		STATE:			CO
		ZIP:			80203
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2013-07-01</periodOfReport>

    <dateOfOriginalSubmission>2013-07-03</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000893538</issuerCik>
        <issuerName>SM Energy Co</issuerName>
        <issuerTradingSymbol>SM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001364843</rptOwnerCik>
            <rptOwnerName>BEST ANTHONY JAMES</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1775 SHERMAN STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1200</rptOwnerStreet2>
            <rptOwnerCity>DENVER</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80203</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock; $.01 Par Value</value>
            </securityTitle>
            <transactionDate>
                <value>2013-06-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>478</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>44.38</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>143559</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person purchased 478 shares of common stock on June 28, 2013, from the issuer's Employee Stock Purchase Plan.</footnote>
        <footnote id="F2">The purpose of this amendment is to correct a clerical error in Table 1, Number 5., Amount of Securities Beneficially Owned Following Reported Transaction(s), which was originally reported as 219,748 shares of common stock but which is now corrected to 143,559 shares of common stock.  The error was carried forward in the reporting person's subsequent Form 4 filed on July 5, 2013.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Karin M. Writer (Attorney-In-Fact)</signatureName>
        <signatureDate>2014-01-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
