<SEC-DOCUMENT>0001140361-25-010700.txt : 20250327
<SEC-HEADER>0001140361-25-010700.hdr.sgml : 20250327
<ACCEPTANCE-DATETIME>20250327161557
ACCESSION NUMBER:		0001140361-25-010700
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250325
FILED AS OF DATE:		20250327
DATE AS OF CHANGE:		20250327

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NMSIC Co-Investment Fund, L.P.
		CENTRAL INDEX KEY:			0001788331
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39049
		FILM NUMBER:		25779511

	BUSINESS ADDRESS:	
		STREET 1:		C/O EXAGEN INC.
		STREET 2:		1261 LIBERTY WAY, SUITE C
		CITY:			VISTA
		STATE:			CA
		ZIP:			92081
		BUSINESS PHONE:		(760) 560-1501

	MAIL ADDRESS:	
		STREET 1:		C/O EXAGEN INC.
		STREET 2:		1261 LIBERTY WAY, SUITE C
		CITY:			VISTA
		STATE:			CA
		ZIP:			92081

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Sun Mountain Capital Partners LLC
		CENTRAL INDEX KEY:			0001788530
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39049
		FILM NUMBER:		25779510

	BUSINESS ADDRESS:	
		STREET 1:		C/O EXAGEN INC.
		STREET 2:		1261 LIBERTY WAY, SUITE C
		CITY:			VISTA
		STATE:			CA
		ZIP:			92081
		BUSINESS PHONE:		(760) 560-1501

	MAIL ADDRESS:	
		STREET 1:		C/O EXAGEN INC.
		STREET 2:		1261 LIBERTY WAY, SUITE C
		CITY:			VISTA
		STATE:			CA
		ZIP:			92081

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
		EIN:				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
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-03-25</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001788331</rptOwnerCik>
            <rptOwnerName>NMSIC Co-Investment Fund, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>527 DON GASPAR AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTA FE</rptOwnerCity>
            <rptOwnerState>NM</rptOwnerState>
            <rptOwnerZipCode>87505</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isTenPercentOwner>true</isTenPercentOwner>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001788530</rptOwnerCik>
            <rptOwnerName>Sun Mountain Capital Partners LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>527 DON GASPAR AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTA FE</rptOwnerCity>
            <rptOwnerState>NM</rptOwnerState>
            <rptOwnerZipCode>87505</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isTenPercentOwner>true</isTenPercentOwner>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-03-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>350000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.3</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1758958</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The shares reported on this form are held of record by NMSIC Co-Investment Fund, L.P. (&quot;NMSIC&quot;). Sun Mountain Capital Partners LLC (&quot;Sun Mountain&quot;) is the general partner of NMSIC. The controlling members of Sun Mountain are Brian Birk, Sally Coming and Lee Rand. As such, each of these entities and individuals may be deemed to share beneficial ownership of the shares held of record by NMSIC. Each of Sun Mountain, Mr. Birk, Ms. Coming and Mr. Rand disclaims beneficial ownership of the securities held of record by NMSIC.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>NMSIC Co-Investment Fund, L.P., By: Sun Mountain Capital Partners LLC, its general partner, /s/ Brian Birk, Name: Brian Birk, Title: Managing Partner, /s/ Lee Rand, Name: Lee Rand, Title: Managing Member</signatureName>
        <signatureDate>2025-03-27</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Sun Mountain Capital Partners LLC, /s/ Brian Birk, Name: Brian Birk, Title: Managing Partner, /s/ Lee Rand, Name: Lee Rand, Title: Managing Member</signatureName>
        <signatureDate>2025-03-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
