of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

Director — Ana Hooker: Ms. Hooker resigned from the Board of Directors, including all committees.

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

Results of Operations and Financial Condition. On January 11, 2026, Exagen Inc. (the “Company”) announced in a press release (the “Press Release”) certain select preliminary unaudited financial information and results of operations for the three months and year ended December 31, 2025, based on currently available information. A copy of the Press Release issued by the Company is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The Company’s financial closing procedures with respe…

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

Director — Charles S. McKhann: Charles S. McKhann was appointed as a Class III director and joined the Compensation Committee and Nominating Committee.

Entry into a Material Definitive Agreement. On May 8, 2025, Exagen Inc. (the “ Company ”) entered into an underwriting agreement (the “ Underwriting Agreement ”) by and between Canaccord Genuity LLC (the “ Underwriter ”) relating to the issuance and sale of an aggregate of 3,350,000 shares (the “ Firm Shares ”) of the Company’s common stock, par value $0.001 per share (the “ Common Stock ”), to the Underwriter at a price to the public of $5.25 per share (the “ Offering ”). Pursuant to the ter…

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

Regulation FD Disclosure. On April 28, 2025, the Company issued a press release announcing the entry into the Credit Agreement. A copy of the press release is furnished as Exhibit 99.1 hereto and is incorporated herein by reference. The information in the press release is being furnished, not filed, pursuant to

Entry into a Material Definitive Agreement. Entry into Perceptive Term Loan Facility On April 25, 2025 (the “Closing Date”), Exagen Inc. (the “Company”) entered into a Credit Agreement and Guaranty (the “Credit Agreement”) with Perceptive Credit Holdings IV, LP, as lender and administrative agent (“Perceptive”), which provides for a senior secured delayed draw term loan facility in an aggregate principal amount of up to $75.0 million (the “Perceptive Term Loan Facility”). An initial tranche o…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information required by this

relating to the Warrant Certificate and the Warrant Shares is set forth under

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

Results of Operations and Financial Condition. On January 12, 2025, Exagen Inc. (the “Company”) announced in a press release (the “Press Release”) certain select preliminary unaudited financial information and results of operations for the three months and year ended December 31, 2024, based on currently available information. A copy of the Press Release issued by the Company is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The Company’s financial closing procedures with respe…

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

Chief Financial Officer — Jeffrey Black: Exagen Inc. appointed Jeffrey Black as the new Chief Financial Officer, effective September 1, 2024.

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

Results of Operations and Financial Condition. On January 7, 2024 , Exagen Inc. (the "Company") provided select preliminary unaudited financial information and results of operations for the year ended December 31, 2023, based on currently available information. A copy of the press release issued by the Company is furnished as Exhibit 99.1 to this report. The preliminary unaudited financial data included in the press release has been prepared by, and is the responsibility of, our management. B…

Entry into a Material Definitive Agreement. Amendment to Sales Agreement On November 17, 2023, Exagen Inc. (the “Company”) entered into Amendment No. 1 (“Amendment No. 1”) to that certain sales agreement, dated September 15, 2022 (the “Sales Agreement”), by and between the Company and Cowen and Company, LLC (“TD Cowen”) in connection with the continuation of the Company’s at-the-market equity offering program (the “Program”). Pursuant to the terms and conditions of Amendment No. 1, the Compan…

of this report, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filings under the Exchange Act or under the Securities Act of 1933, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such fi…

Termination of a Material Definitive Agreement. The disclosure set forth under