X0306 4/A 2020-01-08 2020-01-10 0 0001478320 Adaptive Biotechnologies Corp ADPT 0001799081 Taylor Stacy L C/O ADAPTIVE BIOTECHNOLOGIES 1551 EASTLAKE AVE E STE 200 SEATTLE WA 98102 0 1 0 0 SVP and General Counsel Common Stock 2020-01-08 4 M 0 662 6.55 A 1962 D Common Stock 2020-01-08 4 S 0 662 30.00 D 1300 D Stock Option (Right to Buy) 6.55 2020-01-08 4 M 0 662 0.00 D 2028-04-24 Common Stock 52662 52000 D The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 22, 2019. The options vested with respect to 1/4 of such shares on March 12, 2019, with 1/48 of such shares vesting thereafter at the end of each full month of continuous service until fully vested. /s/ Stacy L. Taylor by Eric Billings as attorney-in-fact 2020-02-18