<SEC-DOCUMENT>0001104659-18-058816.txt : 20180926
<SEC-HEADER>0001104659-18-058816.hdr.sgml : 20180926
<ACCEPTANCE-DATETIME>20180926183313
ACCESSION NUMBER:		0001104659-18-058816
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180924
FILED AS OF DATE:		20180926
DATE AS OF CHANGE:		20180926

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Mintzer Jennifer F.
		CENTRAL INDEX KEY:			0001739199

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15319
		FILM NUMBER:		181089079

	MAIL ADDRESS:	
		STREET 1:		C/O SENIOR HOUSING PROPERTIES TRUST
		STREET 2:		TWO NEWTON PL., 255 WASHINGTON STREET
		CITY:			NEWTON
		STATE:			MA
		ZIP:			02458

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SENIOR HOUSING PROPERTIES TRUST
		CENTRAL INDEX KEY:			0001075415
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				043445278
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		C/O THE RMR GROUP
		STREET 2:		TWO NEWTON PL., 255 WASH. ST., STE. 300
		CITY:			NEWTON
		STATE:			MA
		ZIP:			02458
		BUSINESS PHONE:		(617) 796-8350

	MAIL ADDRESS:	
		STREET 1:		C/O THE RMR GROUP
		STREET 2:		TWO NEWTON PL., 255 WASH. ST., STE. 300
		CITY:			NEWTON
		STATE:			MA
		ZIP:			02458
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>a4.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-09-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001075415</issuerCik>
        <issuerName>SENIOR HOUSING PROPERTIES TRUST</issuerName>
        <issuerTradingSymbol>NASDAQ:SNH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001739199</rptOwnerCik>
            <rptOwnerName>Mintzer Jennifer F.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE RMR GROUP LLC</rptOwnerStreet1>
            <rptOwnerStreet2>TWO NEWTON PL., 255 WASH. ST., STE. 300</rptOwnerStreet2>
            <rptOwnerCity>NEWTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02458</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and COO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares of Beneficial Interest</value>
            </securityTitle>
            <transactionDate>
                <value>2018-09-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>809</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.56</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15362</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>/s/ Jennifer F. Mintzer</signatureName>
        <signatureDate>2018-09-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
