X0306 4 2022-03-01 0001604464 Atara Biotherapeutics, Inc. ATRA 0001803794 Yarema Kristin C/O ATARA BIOTHERAPEUTICS, INC. 611 GATEWAY BLVD., SUITE 900 SOUTH SAN FRANCISCO CA 94080 true Chief Commercial Officer Common Stock 2022-03-01 4 A 0 45533 0 A 171415 D Employee Stock Option (Right to Buy) 10.21 2022-03-01 4 A 0 85592 0 A 2032-02-28 Common Stock 85592 85592 D These restricted stock units vest in 16 equal quarterly installments on each Company Quarterly Vesting Date (as defined below), with the initial installment vesting on May 15, 2022, subject to the reporting person's continuous service. Company Quarterly Vesting Date means March 1, May 15, August 15 and November 15 of each year. 1/48th of the shares subject to the stock option vest and become exercisable each month with the initial installment vesting on April 1, 2022, subject to the reporting person's continuous service. /s/ David Tucker, Attorney-in-Fact for Kristin Yarema 2022-03-03