X0306 4 2019-09-23 0 0001274737 EXAGEN INC. XGN 0001788396 H.I.G. Bio-Exagen, L.P. 1450 BRICKELL AVENUE, 31ST FLOOR MIAMI FL 33131 0 0 1 0 0001788482 H.I.G.-GPII, Inc. 1450 BRICKELL AVENUE, 31ST FLOOR MIAMI FL 33131 0 0 1 0 0001050045 TAMER ANTHONY 1450 BRICKELL AVENUE, 31ST FLOOR MIAMI FL 33131 0 0 1 0 0001050046 MNAYMNEH SAMI 1450 BRICKELL AVENUE, 31ST FLOOR MIAMI FL 33131 0 0 1 0 Common Stock 2019-09-23 4 C 0 1271252 0.00 A 1271252 I See footnote Common Stock 2019-09-23 4 P 0 425000 14.00 A 1696252 I See footnote Series H Redeemable Convertible Preferred Stock 2019-09-23 4 C 0 233446519 D Common Stock 1271252 0 I See footnote The shares reported on this form are held of record by H.I.G. Bio-Exagen, L.P. ("H.I.G."). H.I.G.-GPII, Inc. ("H.I.G. GP") is the general partner of H.I.G. and has sole voting and investment control over the shares owned by H.I.G. Anthony Tamer and Sami Mnaymneh are the sole shareholders of H.I.G. GP and may be deemed to share beneficial ownership of the shares held by H.I.G. Bio-Exagen, L.P. Each of Mr. Tamer and Mr. Mnaymneh disclaims beneficial ownership of the shares reported herein except to the extent of their pecuniary interest, if any. The Series H Redeemable Convertible Preferred Stock ("Series H") is convertible into the Issuer's Common Stock on a 183.635-for-one basis at the holder's election and has no expiration date. The Series H automatically converted into Common Stock upon the closing of the Issuer's initial public offering. H.I.G. Bio-Exagen, L.P., By: H.I.G.-GPII, Inc., its general partner, /s/ Richard Siegel, Name: Richard Siegel, Title: Authorized Signatory 2019-09-23 H.I.G.-GPII, Inc., By: H.I.G.-GPII, Inc., its general partner, /s/ Richard Siegel, Name: Richard Siegel, Title: Authorized Signatory 2019-09-23 /s/ Anthony Tamer 2019-09-23 /s/ Sami Mnaymneh 2019-09-23