<SEC-DOCUMENT>0001140361-25-014389.txt : 20250417
<SEC-HEADER>0001140361-25-014389.hdr.sgml : 20250417
<ACCEPTANCE-DATETIME>20250417161537
ACCESSION NUMBER:		0001140361-25-014389
CONFORMED SUBMISSION TYPE:	SCHEDULE 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20250417
DATE AS OF CHANGE:		20250417

SUBJECT COMPANY:	

	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

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-91300
		FILM NUMBER:		25847507

	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

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NMSIC Co-Investment Fund, L.P.
		CENTRAL INDEX KEY:			0001788331
		ORGANIZATION NAME:           	
		EIN:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>SCHEDULE 13G/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/schedule13g" xmlns:com="http://www.sec.gov/edgar/common">
<headerData>
<submissionType>SCHEDULE 13G/A</submissionType>
<previousAccessionNumber>0001140361-20-020885</previousAccessionNumber>
<filerInfo>
<filer>
<filerCredentials>
<cik>0001788331</cik>
<ccc>XXXXXXXX</ccc>
</filerCredentials>
</filer>
<liveTestFlag>LIVE</liveTestFlag>



</filerInfo>
</headerData>
<formData>
<coverPageHeader>
<amendmentNo>6</amendmentNo>
<securitiesClassTitle>Common Stock, par value $0.001 per share</securitiesClassTitle>
<eventDateRequiresFilingThisStatement>03/25/2025</eventDateRequiresFilingThisStatement>
<issuerInfo>
<issuerCik>0001274737</issuerCik>
<issuerName>EXAGEN INC.</issuerName>
<issuerCusip>30068X103</issuerCusip>
<issuerPrincipalExecutiveOfficeAddress>
<com:street1>1261 Liberty Way</com:street1>
<com:city>Vista</com:city>
<com:stateOrCountry>CA</com:stateOrCountry>
<com:zipCode>92081</com:zipCode>
</issuerPrincipalExecutiveOfficeAddress>
</issuerInfo>
<designateRulesPursuantThisScheduleFiled>
<designateRulePursuantThisScheduleFiled>Rule 13d-1(d)</designateRulePursuantThisScheduleFiled>
</designateRulesPursuantThisScheduleFiled>
</coverPageHeader>
<coverPageHeaderReportingPersonDetails>

<reportingPersonName>NMSIC Co-Investment Fund, L.P.</reportingPersonName>
<citizenshipOrOrganization>DE</citizenshipOrOrganization>
<reportingPersonBeneficiallyOwnedNumberOfShares>
<soleVotingPower>1758958</soleVotingPower>
<sharedVotingPower>0</sharedVotingPower>
<soleDispositivePower>1758958</soleDispositivePower>
<sharedDispositivePower>0</sharedDispositivePower>
</reportingPersonBeneficiallyOwnedNumberOfShares>
<reportingPersonBeneficiallyOwnedAggregateNumberOfShares>1758958</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
<aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
<classPercent>9.83</classPercent>
<typeOfReportingPerson>PN</typeOfReportingPerson>
<comments>(1) Percentage calculated based on 17,898,098 shares of common stock outstanding as of March 7, 2025, as reported in the issuer's Annual Report on Form 10-K for the year ended December 31, 2024.</comments>
</coverPageHeaderReportingPersonDetails>
<coverPageHeaderReportingPersonDetails>

<reportingPersonName>Sun Mountain Capital Partners, L.L.C.</reportingPersonName>
<citizenshipOrOrganization>DE</citizenshipOrOrganization>
<reportingPersonBeneficiallyOwnedNumberOfShares>
<soleVotingPower>1758958</soleVotingPower>
<sharedVotingPower>0</sharedVotingPower>
<soleDispositivePower>1758958</soleDispositivePower>
<sharedDispositivePower>0</sharedDispositivePower>
</reportingPersonBeneficiallyOwnedNumberOfShares>
<reportingPersonBeneficiallyOwnedAggregateNumberOfShares>1758958</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
<aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
<classPercent>9.83</classPercent>
<typeOfReportingPerson>PN</typeOfReportingPerson>
<comments>(1) Percentage calculated based on 17,898,098 shares of common stock outstanding as of March 7, 2025, as reported in the issuer's Annual Report on Form 10-K for the year ended December 31, 2024.</comments>
</coverPageHeaderReportingPersonDetails>
<items>
<item1>
<issuerName>EXAGEN INC.</issuerName>
<issuerPrincipalExecutiveOfficeAddress>1261 Liberty Way, Vista, California, 92081</issuerPrincipalExecutiveOfficeAddress>
</item1>
<item2>
<filingPersonName>This statement is being filed on behalf of each of the following persons (each, a "Reporting Person" and together, the "Reporting Persons"):&#13;
&#13;
(i) NMSIC Co-Investment Fund, L.P. ("NMSIC"); and&#13;
&#13;
ii) Sun Mountain Capital Partners, L.L.C. ("Sun Mountain"), the general partner of NMSIC.</filingPersonName>
<principalBusinessOfficeOrResidenceAddress>The address of the principal business office of each of the Reporting Persons is: &#13;
&#13;
527 Don Gaspar Avenue&#13;
Santa Fe, New Mexico 87505</principalBusinessOfficeOrResidenceAddress>
<citizenship>See row 4 of the cover page of each Reporting Person.</citizenship>
</item2>
<item3>
<notApplicableFlag>Y</notApplicableFlag>
</item3>
<item4>
<amountBeneficiallyOwned>See row 9 of the cover page of each Reporting Person.	&#13;
&#13;
NMSIC directly owns 1,758,958 shares of common stock, par value $0.001 per share (the "Common Stock"), of the issuer. Sun Mountain 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. &#13;
&#13;
Pursuant to Rule 13d-4 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), the Reporting Persons declare that filing this Schedule 13G shall not be construed as an admission that any such person is, for the purposes of Section 13(d) and/or Section 13(g) of the Exchange Act, the beneficial owner of any Common Stock covered by this Schedule 13G except to the extent of such person's direct ownership of such Common Stock, and except to the extent of such direct ownership, such beneficial ownership is expressly disclaimed by each such person.</amountBeneficiallyOwned>
<classPercent>Each of the Reporting Persons may be deemed to be the beneficial owner of 9.83% of the outstanding shares of the Common Stock.&#13;
&#13;
The calculation of beneficial ownership percentage is based on 17,898,098 shares of Common Stock outstanding as of March 7, 2025, as reported by the issuer in its Annual Report on Form 10-K for the year ended December 31, 2024, filed with the Securities and Exchange Commission on March 11, 2025.</classPercent>
<numberOfSharesPersonHas>
<solePowerOrDirectToVote>See row 5 of the cover page of each Reporting Person.</solePowerOrDirectToVote>
<sharedPowerOrDirectToVote>See row 6 of the cover page of each Reporting Person.</sharedPowerOrDirectToVote>
<solePowerOrDirectToDispose>See row 7 of the cover page of each Reporting Person.</solePowerOrDirectToDispose>
<sharedPowerOrDirectToDispose>See row 8 of the cover page of each Reporting Person.</sharedPowerOrDirectToDispose>
</numberOfSharesPersonHas>
</item4>
<item5>
<notApplicableFlag>Y</notApplicableFlag>
</item5>
<item6>
<notApplicableFlag>Y</notApplicableFlag>
</item6>
<item7>
<notApplicableFlag>Y</notApplicableFlag>
</item7>
<item8>
<notApplicableFlag>Y</notApplicableFlag>
</item8>
<item9>
<notApplicableFlag>Y</notApplicableFlag>
</item9>
<item10>
<notApplicableFlag>Y</notApplicableFlag>
</item10>
</items>
<signatureInformation>
<reportingPersonName>NMSIC Co-Investment Fund, L.P.</reportingPersonName>
<signatureDetails>
<signature>/s/ Brian Birk</signature>
<title>Brian Birk, Managing Member of Sun Mountain Capital Partners, L.L.C., the general partner of NMSIC Co-Investment Fund, L.P.</title>
<date>04/17/2025</date>
</signatureDetails>
<signatureDetails>
<signature>/s/ Lee Rand</signature>
<title>Lee Rand, Managing Member of Sun Mountain Capital Partners, L.L.C., the general partner of NMSIC Co-Investment Fund, L.P.</title>
<date>04/17/2025</date>
</signatureDetails>
</signatureInformation>
<signatureInformation>
<reportingPersonName>Sun Mountain Capital Partners, L.L.C.</reportingPersonName>
<signatureDetails>
<signature>/s/ Brian Birk</signature>
<title>Brian Birk, Managing Member</title>
<date>04/17/2025</date>
</signatureDetails>
<signatureDetails>
<signature>/s/ Lee Rand</signature>
<title>Lee Rand, Managing Member</title>
<date>04/17/2025</date>
</signatureDetails>
</signatureInformation>
</formData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
