<SEC-DOCUMENT>0000939057-16-000822.txt : 20160509
<SEC-HEADER>0000939057-16-000822.hdr.sgml : 20160509
<ACCEPTANCE-DATETIME>20160509132850
ACCESSION NUMBER:		0000939057-16-000822
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160506
FILED AS OF DATE:		20160509
DATE AS OF CHANGE:		20160509

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FS Bancorp, Inc.
		CENTRAL INDEX KEY:			0001530249
		STANDARD INDUSTRIAL CLASSIFICATION:	SAVINGS INSTITUTIONS, NOT FEDERALLY CHARTERED [6036]
		IRS NUMBER:				454585178
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6920 220TH STREET SW
		STREET 2:		SUITE 300
		CITY:			MOUNTLAKE TERRACE
		STATE:			WA
		ZIP:			98043
		BUSINESS PHONE:		800-683-0973

	MAIL ADDRESS:	
		STREET 1:		6920 220TH STREET SW
		STREET 2:		SUITE 300
		CITY:			MOUNTLAKE TERRACE
		STATE:			WA
		ZIP:			98043

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Mullet Matthew D.
		CENTRAL INDEX KEY:			0001548095

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35589
		FILM NUMBER:		161630887

	MAIL ADDRESS:	
		STREET 1:		C/O FS BANCORP, INC.
		STREET 2:		6920 220TH STREET SW, SUITE 300
		CITY:			MOUNTLAKE TERRACE
		STATE:			WA
		ZIP:			98043
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-05-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001530249</issuerCik>
        <issuerName>FS Bancorp, Inc.</issuerName>
        <issuerTradingSymbol>FSBW</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001548095</rptOwnerCik>
            <rptOwnerName>Mullet Matthew D.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FS BANCORP, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>6920 220TH STREET SW, SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>MOUNTLAKE TERRACE</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-05-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>950</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>25</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17050</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Stock award</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11062</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By IRA</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3468</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2800</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By spouse's IRA</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares withheld by FS Bancorp, Inc. to satisfy tax withholding obligations in connection with the vesting of 3,600 shares of restricted stock on May 6, 2016 of the 18,000 shares of restricted stock granted to the reporting person on May 8, 2014.</footnote>
        <footnote id="F2">Includes shares of restricted stock that vested on May 8, 2015 and on May 6, 2016.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/Matthew D. Mullet</signatureName>
        <signatureDate>2016-05-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
