<SEC-DOCUMENT>0001388658-21-000043.txt : 20210303
<SEC-HEADER>0001388658-21-000043.hdr.sgml : 20210303
<ACCEPTANCE-DATETIME>20210303122011
ACCESSION NUMBER:		0001388658-21-000043
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210301
FILED AS OF DATE:		20210303
DATE AS OF CHANGE:		20210303

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Day Mark J.
		CENTRAL INDEX KEY:			0001769845

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37918
		FILM NUMBER:		21707872

	MAIL ADDRESS:	
		STREET 1:		C/O IRHYTHM TECHNOLOGIES, INC.
		STREET 2:		650 TOWNSEND STREET, SUITE 500
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94103

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			iRhythm Technologies, Inc.
		CENTRAL INDEX KEY:			0001388658
		STANDARD INDUSTRIAL CLASSIFICATION:	SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
		IRS NUMBER:				208149544
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		650 TOWNSEND STREET
		STREET 2:		SUITE 500
		CITY:			San Francisco
		STATE:			CA
		ZIP:			94103
		BUSINESS PHONE:		415-632-5700

	MAIL ADDRESS:	
		STREET 1:		650 TOWNSEND STREET
		STREET 2:		SUITE 500
		CITY:			San Francisco
		STATE:			CA
		ZIP:			94103

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	IRhythm Technologies, Inc.
		DATE OF NAME CHANGE:	20110429

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	IRhythm Technologies Inc
		DATE OF NAME CHANGE:	20070201
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_161479199721196.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-03-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001388658</issuerCik>
        <issuerName>iRhythm Technologies, Inc.</issuerName>
        <issuerTradingSymbol>IRTC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001769845</rptOwnerCik>
            <rptOwnerName>Day Mark J.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IRHYTHM TECHNOLOGIES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>699 8TH ST # 600</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94103</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP, Research &amp; Development</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-03-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2518</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>152.92</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>36962</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares that have been withheld by the Issuer to satisfy income tax withholding and remittance obligations in connection with the vesting and net settlement of restricted stock units previously reported.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Christina Delfin, attorney in fact</signatureName>
        <signatureDate>2021-03-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
