<SEC-DOCUMENT>0001110805-20-000006.txt : 20200203
<SEC-HEADER>0001110805-20-000006.hdr.sgml : 20200203
<ACCEPTANCE-DATETIME>20200203202555
ACCESSION NUMBER:		0001110805-20-000006
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200130
FILED AS OF DATE:		20200203
DATE AS OF CHANGE:		20200203

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Barron Bradley C
		CENTRAL INDEX KEY:			0001349304

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-16417
		FILM NUMBER:		20570342

	MAIL ADDRESS:	
		STREET 1:		19003 IH-10 WEST
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78257

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NuStar Energy L.P.
		CENTRAL INDEX KEY:			0001110805
		STANDARD INDUSTRIAL CLASSIFICATION:	PIPE LINES (NO NATURAL GAS) [4610]
		IRS NUMBER:				742956831
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		19003 IH-10 WEST
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78257
		BUSINESS PHONE:		(210) 918-2000

	MAIL ADDRESS:	
		STREET 1:		19003 IH-10 WEST
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78257

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	VALERO L P
		DATE OF NAME CHANGE:	20020110

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SHAMROCK LOGISTICS LP
		DATE OF NAME CHANGE:	20000331
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_158077953686169.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-01-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001110805</issuerCik>
        <issuerName>NuStar Energy L.P.</issuerName>
        <issuerTradingSymbol>NS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001349304</rptOwnerCik>
            <rptOwnerName>Barron Bradley C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>19003 IH-10 WEST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN ANTONIO</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78257</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO &amp; President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Units</value>
            </securityTitle>
            <transactionDate>
                <value>2020-01-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>48869</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>288705</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Units</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <transactionDate>
                <value>2020-01-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>19345</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>28.20</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>269360</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On January 30, 2020, the Compensation Committee of the Board of Directors of NuStar GP, LLC, the general partner of the Issuer's general partner, determined that the performance units available to vest with respect to 2019 performance vested at 198%.</footnote>
        <footnote id="F2">Reflects common units not distributed to the reporting person in order to satisfy the reporting person's tax obligations on grants.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michelle S. Miller, as Attorney-in-Fact for Bradley C. Barron</signatureName>
        <signatureDate>2020-02-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
