Exagen (XGN) S-8Registration of securities for employees

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 852,297 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 provision 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 and 333-272038, 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2019 Plan and 2019 ESPP, are incorporated into this Registration Statement by reference to the extent not modified or superseded hereby or by any subsequently filed document, which is incorporated by reference herein or therein.

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. 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.

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:

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.