<SEC-DOCUMENT>0001395942-18-000019.txt : 20180208
<SEC-HEADER>0001395942-18-000019.hdr.sgml : 20180208
<ACCEPTANCE-DATETIME>20180208210639
ACCESSION NUMBER:		0001395942-18-000019
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180206
FILED AS OF DATE:		20180208
DATE AS OF CHANGE:		20180208

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Kett John W
		CENTRAL INDEX KEY:			0001295822

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34568
		FILM NUMBER:		18587415

	MAIL ADDRESS:	
		STREET 1:		TWO WESTBROOK CORPORATE CENTER
		CITY:			WESTCHESTER
		STATE:			IL
		ZIP:			60154

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KAR Auction Services, Inc.
		CENTRAL INDEX KEY:			0001395942
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-AUTO DEALERS & GASOLINE STATIONS [5500]
		IRS NUMBER:				208744739
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		13085 HAMILTON CROSSING BOULEVARD
		CITY:			CARMEL
		STATE:			IN
		ZIP:			46032
		BUSINESS PHONE:		(800) 923-3725

	MAIL ADDRESS:	
		STREET 1:		13085 HAMILTON CROSSING BOULEVARD
		CITY:			CARMEL
		STATE:			IN
		ZIP:			46032

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KAR Holdings, Inc.
		DATE OF NAME CHANGE:	20070409
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_151814198454120.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-02-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001395942</issuerCik>
        <issuerName>KAR Auction Services, Inc.</issuerName>
        <issuerTradingSymbol>KAR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001295822</rptOwnerCik>
            <rptOwnerName>Kett John W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>13085 HAMILTON CROSSING BLVD.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CARMEL</rptOwnerCity>
            <rptOwnerState>IN</rptOwnerState>
            <rptOwnerZipCode>46032</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>IAA CEO &amp; President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-02-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>14043.6532</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>70014.6532</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-02-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4986</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>51.04</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>65028.6532</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F4"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1072.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1072</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F4"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F6"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2332.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2332</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F4"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-02-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3273</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F7"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F7"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3273.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3273</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The number of performance-based restricted stock units that vested was determined based on the Company's cumulative adjusted net income per share exceeding certain levels over the three-year period beginning on January 1, 2015 and ending on December 31, 2017.</footnote>
        <footnote id="F2">Each performance-based restricted stock unit is convertible into a share of common stock on a 1-for-1 basis. The performance-based restricted stock units vested into common stock on February 6, 2018.</footnote>
        <footnote id="F3">Shares withheld by the Company to satisfy tax withholding requirements.</footnote>
        <footnote id="F4">Converts into common stock on a 1-for-1 basis.</footnote>
        <footnote id="F5">These restricted stock units remain subject to a time-vesting requirement and are scheduled to vest and settle in common stock as follows: one-third of these restricted stock units vested on February 20, 2016, one-third of these restricted stock units vested on February 20, 2017 and the remaining one-third of these restricted stock units vest on February 20, 2018, assuming continued employment through the applicable vesting date.</footnote>
        <footnote id="F6">These restricted stock units remain subject to a time-vesting requirement and are scheduled to vest and settle in common stock as follows: one-third of these restricted stock units vested on February 23, 2017, one-third of these restricted stock units vest on February 22, 2018 and the remaining one-third of these restricted stock units vest on February 22, 2019, assuming continued employment through the applicable vesting date.</footnote>
        <footnote id="F7">The compensation committee certified on February 6, 2018 that the Company achieved the 2017 net income performance goal for the restricted stock unit awards granted in 2017 under the KAR Auction Services, Inc. 2009 Omnibus Stock and Incentive Plan. These restricted stock units remain subject to a time-vesting requirement and are scheduled to vest and settle in common stock as follows: one-third of these restricted stock units vest on February 24, 2018, one-third of these restricted stock units vest on February 24, 2019 and the remaining one-third of these restricted stock units vest on February 24, 2020, assuming continued employment through the applicable vesting date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Rebecca C. Polak, Attorney In Fact</signatureName>
        <signatureDate>2018-02-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
