<SEC-DOCUMENT>0001628280-25-010181.txt : 20250304
<SEC-HEADER>0001628280-25-010181.hdr.sgml : 20250304
<ACCEPTANCE-DATETIME>20250304200616
ACCESSION NUMBER:		0001628280-25-010181
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250228
FILED AS OF DATE:		20250304
DATE AS OF CHANGE:		20250304

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Dickens Zachary T
		CENTRAL INDEX KEY:			0001799962
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32269
		FILM NUMBER:		25708061

	MAIL ADDRESS:	
		STREET 1:		2795 E COTTONWOOD PARKWAY
		STREET 2:		SUITE 300
		CITY:			SALT LAKE CITY
		STATE:			UT
		ZIP:			84121

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Extra Space Storage Inc.
		CENTRAL INDEX KEY:			0001289490
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		ORGANIZATION NAME:           	05 Real Estate & Construction
		IRS NUMBER:				201076777
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2795 COTTONWOOD PARKWAY, SUITE 400
		CITY:			SALT LAKE CITY
		STATE:			UT
		ZIP:			84121
		BUSINESS PHONE:		801-562-5556

	MAIL ADDRESS:	
		STREET 1:		2795 COTTONWOOD PARKWAY, SUITE 400
		CITY:			SALT LAKE CITY
		STATE:			UT
		ZIP:			84121
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1741136770.xml
<DESCRIPTION>FORM 4
<TEXT>
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    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-02-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001289490</issuerCik>
        <issuerName>Extra Space Storage Inc.</issuerName>
        <issuerTradingSymbol>EXR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001799962</rptOwnerCik>
            <rptOwnerName>Dickens Zachary T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2795 EAST COTTONWOOD PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>SALT LAKE CITY</rptOwnerCity>
            <rptOwnerState>UT</rptOwnerState>
            <rptOwnerZipCode>84121</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP, Chief Investment Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
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            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-03-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>1718</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>152.56</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
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            </transactionAmounts>
            <postTransactionAmounts>
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                    <value>20853</value>
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                    <value>D</value>
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            <securityTitle>
                <value>Common Stock</value>
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                <transactionCode>F</transactionCode>
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        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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            <transactionDate>
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                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                    <value>352</value>
                    <footnoteId id="F3"/>
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                <transactionAcquiredDisposedCode>
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                <sharesOwnedFollowingTransaction>
                    <value>27276</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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            <transactionDate>
                <value>2025-03-01</value>
            </transactionDate>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>445</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>152.56</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
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                <sharesOwnedFollowingTransaction>
                    <value>26831</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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            <transactionDate>
                <value>2025-02-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>80</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>152.66</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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                <sharesOwnedFollowingTransaction>
                    <value>0</value>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Roth IRA</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the number of shares of common stock issued upon the vesting of performance stock units (PSUs). Each PSU represented a contingent right to receive shares of the Issuers common stock. The PSUs were originally granted on February 14, 2022 and were eligible to vest based on the Issuer achievement of certain performance objectives during the three-year performance period ending December 31, 2024. On February 11, 2025, the Compensation Committee of the Board of Directors of the Issuer certified the Issuer achievement relative to the applicable performance objectives and approved the vesting of the PSUs with respect to these shares effective March 1, 2025.</footnote>
        <footnote id="F2">Restricted stock awards vest 25% annually over four years, beginning on the first anniversary of the grant date.</footnote>
        <footnote id="F3">Represents shares withheld by the Issuer in payment of the tax liability arising in connection with the settlement of vested restricted stock awards. Restricted stock awards vest 25% annually over four years, beginning on the first anniversary of the grant date.</footnote>
        <footnote id="F4">The information in this report is based on plan information as of February 28, 2025.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Grace Kunde, Attorney-in-Fact</signatureName>
        <signatureDate>2025-03-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
