<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-04-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000722723</issuerCik>
        <issuerName>HANGER, INC.</issuerName>
        <issuerTradingSymbol>HGR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001466989</rptOwnerCik>
            <rptOwnerName>Hartman Thomas E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>10910 DOMAIN DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>AUSTIN</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78758</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP and General Counsel</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-04-29</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25858</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents a grant of time-based restricted stock under the Company's 2016 Omnibus Incentive Plan (the &quot;Plan&quot;), which vests to the extent of 25% annually beginning on March 7, 2017 and cumulatively vests to the extent of 25% each year thereafter.  The restricted stock being reported does not include the contingent right of the reporting person to receive up to 10,000 additional performance shares under the Plan based on the achievement of certain performance targets for the fiscal year 2016.</footnote>
        <footnote id="F2">Consists of (i) unvested restricted shares totaling 10,000 shares of stock from an initial grant of 10,000 shares of restricted stock that begins to vest on March 7, 2017; (ii) unvested restricted shares totaling 4,958 shares of stock from an initial grant of 4,958 shares of restricted stock made on November 10, 2015; (iii) unvested restricted shares and fully vested shares totaling 4,239 shares of stock from an initial grant of 4,239 shares of restricted stock made on March 6, 2015; (iv) unvested restricted shares and fully vested shares totaling 1,589 shares of stock from an initial grant of 1,731 shares of restricted stock made on March 7, 2014; (v) unvested restricted shares and fully vested shares totaling 2,219 shares of stock from an initial grant of 3,246 shares of restricted stock and performance made on March 11, 2013; [continued in next footnote]</footnote>
        <footnote id="F3">(vi) fully vested shares totaling 2,008 shares from an initial grant of 4,800 shares of restricted stock made on March 7, 2012 and (vii) fully vested shares totaling 845 shares from an initial grant of 4,600 shares of restricted stock made on March 25, 2011 and cumulatively vest to the extent of one-quarter each year thereafter, subject to certain provisions under the Company's 2010 Omnibus Incentive Plan and the Plan, and which shall become fully vested upon a termination of employment not involving termination for cause or voluntary termination.  Except as otherwise noted, all remaining unvested restricted shares will continue to vest at a rate of 25% per year of the original grant amount on the anniversary date of the grant.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jessica Lochmann Allen, Attorney-in-Fact for Thomas E. Hartman</signatureName>
        <signatureDate>2016-05-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
