X0306 4 2022-10-07 0 0001478320 Adaptive Biotechnologies Corp ADPT 0001808905 ADAMS R MARK 1165 EASTLAKE AVE E SEATTLE WA 98109 0 1 0 0 Chief Operating Officer Common Stock 2022-10-07 4 S 0 841 7.61 D 118927 D Common Stock 2022-10-10 4 S 0 2284 7.13 D 116643 D This transaction represents the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of RSUs. This sale is mandated by the Issuer's election under its equity incentive plans to require the satisfaction of tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person. The transaction reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 10, 2022. /s/ R. Mark Adams by Eric Billings, attorney-in-fact 2022-10-11