United States securities and exchange commission logo November 22, 2023 Kamal Adawi Chief Financial Officer Exagen Inc. 1261 Liberty Way Vista, California 92081 Re: Exagen Inc. Registration Statement on Form S-3 Filed November 17, 2023 File No. 333-275362 Dear Kamal Adawi: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Please contact Abby Adams at 202-551-6902 with any questions. Sincerely, Division of Corporation Finance Office of Industrial Applications and Services