X0306 4 2018-12-31 0 0001323885 AtriCure, Inc. ATRC 0001565823 Seith Douglas J 7555 INNOVATION WAY MASON OH 45040 0 1 0 0 Chief Operating Officer Common Stock 2018-12-31 5 A 0 E 252 24.00 A 254958 D Common Stock 3500 I Held by spouse Shares acquired pursuant to the AtriCure, Inc. 2018 Employee Stock Purchase Plan for the period ended December 31, 2018. In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the issuer's common stock on July 2, 2018, which was the first trading day of the applicable offering period. The closing price on July 2, 2018 was $28.24. The Reporting Person disclaims beneficial ownership of these securities, except as to his pecuniary interest therein. /s/ M. Andrew Wade as Attorney-in-Fact for Douglas J. Seith 2019-01-03