Document

S-8 1 exagen-formsx8registration.htm S-8 Document

As filed with the Securities and Exchange Commission on May 12, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT UNDER

THE SECURITIES ACT OF 1933

EXAGEN INC.

(Exact name of registrant as specified in its charter)

Delaware

20-0434866

(State or other jurisdiction of

incorporation or organization)

(I.R.S. Employer

Identification No.)

1261 Liberty Way

Vista, California 92081

(Address of principal executive offices) (Zip code)

Exagen Inc. 2019 Incentive Award Plan

Exagen Inc. 2019 Employee Stock Purchase Plan

(Full title of the plans)

John Aballi

President and Chief Executive Officer

Exagen Inc.

1261 Liberty Way

Vista, California 92081

(760) 560-1501

(Name, address, and telephone number, including area code, of agent for service)

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer

☐

Accelerated filer

☐

Non-accelerated filer

☒

Smaller reporting company

☒

Emerging growth company

☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

EXPLANATORY NOTE

This Registration Statement on Form S-8 is being filed with the Securities and Exchange Commission (the "SEC") for the purpose of registering an additional 1,145,578 shares of common stock of Exagen Inc. (the "Registrant") issuable or which may become issuable under the Exagen Inc. 2019 Incentive Award Plan (the "2019 Plan") and the Exagen Inc. 2019 Employee Stock Purchase Plan (the "2019 ESPP") pursuant to the evergreen provisions of such plans.

Pursuant to General Instruction E on Form S-8, the contents of the prior registration statements on Form S-8, File Nos. 333-233878, 333-256014, 333-264867, 333-272038, 333-279356 and 333-287438, previously filed with respect to the 2019 Plan and 2019 ESPP, are incorporated into this Registration Statement by reference to the extent not modified or superseded hereby or by any subsequently filed document, which is incorporated by reference herein or therein.

PART I

INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

The documents containing the information specified in Part I of Form S-8 will be sent or given to participants as specified by Rule 428(b)(1) of the Securities Act of 1933, as amended (the "Securities Act"). These documents and the documents incorporated by reference into this Registration Statement pursuant to Item 3 of Part II of this Registration Statement, taken together, constitute a prospectus that meets the requirements of Section 10(a) of the Securities Act.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

In this Registration Statement, Exagen Inc. is sometimes referred to as "Registrant," "we," "us" or "our."

Item 3. Incorporation of Documents by Reference

The Securities and Exchange Commission allows us to "incorporate by reference" the information we file with them, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this Registration Statement, and later information filed with the SEC will update and supersede this information. We hereby incorporate by reference into this Registration Statement the following documents previously filed with the SEC:

•The Registrant's Annual Report on Form 10-K for the year ended December 31, 2025, filed with the SEC on March 10, 2026, including the information incorporated by reference into our Annual Report on Form 10-K from our definitive proxy statement for our 2026 Annual Meeting of Stockholders, filed with the SEC on April 27, 2026;

•The Registrant's Quarterly Report on Form 10-Q for the quarter ended March 31, 2026, filed with the SEC on May 11, 2026;

•The Registrant's Current Reports on Form 8-K filed with the SEC on January 12, 2026, March 10, 2026, April 23, 2026 and May 11, 2026; and

•The description of the Registrant's common stock set forth in the Registrant's registration statement on Form 8-A12B (Registration No. 001-39049), filed by the Registrant with the SEC under Section 12(b) of

the Securities Exchange Act of 1934, as amended (the "Exchange Act"), on September 13, 2019, including any amendments or reports filed for the purpose of updating such description.

In addition, all documents filed by the Registrant pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the filing of this registration statement and prior to the filing of a post-effective amendment which indicates that all securities offered hereby have been sold or which de-registers all securities then remaining unsold shall be deemed to be incorporated by reference into this registration statement and to be a part hereof from the date of filing such documents, except as to specific sections of such statements as set forth therein. Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this registration statement to the extent that a statement contained herein or in any other subsequently filed document which also is incorporated or deemed to be incorporated by reference herein modifies or supersedes such statement. Any statement contained herein shall be deemed to be modified or superseded for purposes of this registration statement to the extent that a statement contained in any subsequently filed document which also is incorporated or deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this registration statement.

Under no circumstances shall any information furnished under Item 2.02 or 7.01 of Form 8-K be deemed incorporated herein by reference unless such Form 8-K expressly provides to the contrary.

EXHIBIT INDEX


		Incorporated by Reference
Exhibit Number	Exhibit Description	Form	File No.	Exhibit	Exhibit Filing Date	Filed/Furnished Herewith
4.1	Amended and Restated Certificate of Incorporation.	8-K	001-39049	3.1	9/23/2019
4.2	Amended Restated Bylaws.	8-K	001-39049	3.1	3/22/2021
4.3	Amendment to Amended and Restated Bylaws, dated January 19, 2023.	8-K	001-39049	3.1	1/23/2023
4.4	Specimen stock certificate evidencing the shares of common stock.	S-1/A	333-233446	4.1	9/9/2019
5.1	Opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.					X
23.1	Consent of BDO USA, P.C., independent registered public accounting firm.					X
23.2	Consent of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. (included in Exhibit 5.1).					X
24.1	Power of Attorney (see signature page)					X
99.1	Exagen Inc. 2019 Incentive Award Plan.	S-1/A	333-233446	10.3	9/9/2019
99.2	Form of Option Agreement under Exagen Inc. 2019 Incentive Award Plan.	S-1/A	333-233446	10.4	9/9/2019
99.3	Form of Restricted Stock Unit Agreement under Exagen Inc. 2019 Incentive Award Plan.	10-K	001-39049	10.5	3/16/2021
99.4	Exagen Inc. 2019 Employee Stock Purchase Plan.	S-1/A	333-233446	10.5	9/9/2019
107	Filing Fee Table.					X

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Vista, State of California, on May 12, 2026.


						EXAGEN INC.

			by:			/s/ John Aballi
						John Aballi
						President and Chief Executive Officer
						(Principal Executive Officer)

POWER OF ATTORNEY

Each person whose signature appears below hereby constitutes and appoints John Aballi and Jeffrey G. Black, and each of them singly (with full power to each of them to act alone), his attorneys-in-fact, each with the full power of substitution, for him in any and all capacities, to sign this registration statement, and any amendments thereto (including post-effective amendments), and to file the same, with all exhibits thereto and other documents in connection therewith, with the SEC, hereby ratifying and confirming all that each of said attorneys-in-fact, or his substitute or substitutes, may do or cause to be done by virtue hereof. Pursuant to the requirements of the Securities Act, this registration statement has been signed below by the following persons on behalf of the Registrant and in the capacities and on the dates indicated.

Signature

Title

Date

/s/ John Aballi

President, Chief Executive Officer and Director

May 12, 2026

John Aballi

(Principal Executive Officer)

/s/ Jeffrey G. Black

Chief Financial Officer and Corporate Secretary

May 12, 2026

Jeffrey G. Black

(Principal Financial and Accounting Officer)

/s/ Tina S. Nova, Ph.D.

Executive Chairman of the Board of Directors

May 12, 2026

Tina S. Nova, Ph.D.

/s/ Scott Kahn, Ph.D.

Director

May 12, 2026

Scott Kahn, Ph.D.

/s/ Paul Kim

Director

May 12, 2026

Paul Kim

/s/ Bruce C. Robertson, Ph.D.

Director

May 12, 2026

Bruce C. Robertson, Ph.D.

/s/ Frank Stokes

Director

May 12, 2026

Frank Stokes

/s/ Chas McKhann

Director

May 12, 2026

Chas McKhann