<SEC-DOCUMENT>0001274737-25-000009.txt : 20250225
<SEC-HEADER>0001274737-25-000009.hdr.sgml : 20250225
<ACCEPTANCE-DATETIME>20250225205832
ACCESSION NUMBER:		0001274737-25-000009
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20241114
FILED AS OF DATE:		20250225
DATE AS OF CHANGE:		20250225

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ABALLI JOHN
		CENTRAL INDEX KEY:			0001843113
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39049
		FILM NUMBER:		25665757

	MAIL ADDRESS:	
		STREET 1:		C/O DECIPHER BIOSCIENCES, INC.
		STREET 2:		6925 LUSK BLVD, SUITE 200
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EXAGEN INC.
		CENTRAL INDEX KEY:			0001274737
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MEDICAL LABORATORIES [8071]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1261 LIBERTY WAY
		CITY:			VISTA
		STATE:			CA
		ZIP:			92081
		BUSINESS PHONE:		(760) 560-1501

	MAIL ADDRESS:	
		STREET 1:		1261 LIBERTY WAY
		CITY:			VISTA
		STATE:			CA
		ZIP:			92081

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	EXAGEN DIAGNOSTICS INC
		DATE OF NAME CHANGE:	20031230
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>wk-form4a_1740535106.xml
<DESCRIPTION>FORM 4/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2024-11-14</periodOfReport>

    <dateOfOriginalSubmission>2024-11-18</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001274737</issuerCik>
        <issuerName>EXAGEN INC.</issuerName>
        <issuerTradingSymbol>XGN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001843113</rptOwnerCik>
            <rptOwnerName>ABALLI JOHN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O EXAGEN INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1261 LIBERTY WAY</rptOwnerStreet2>
            <rptOwnerCity>VISTA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92081</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>625093</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>40401</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On November 18, 2024, the reporting person filed a Form 4 which inadvertently reported that, following his purchase of 24,305 shares of common stock, he directly owned 689,799 shares of common stock. In fact, as reported in this amendment, the reporting person directly owned 625,093 shares of common stock and indirectly owned 40,401 shares of common stock.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jeffrey G. Black, as attorney-in-fact</signatureName>
        <signatureDate>2025-02-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
