X0508 4 2025-11-17 0 0001478320 Adaptive Biotechnologies Corp ADPT 0001780662 PISKEL KYLE C/O ADAPTIVE BIOTECHNOLOGIES CORPORATION 1165 EASTLAKE AVE E SEATTLE WA 98109 0 1 0 0 Chief Financial Officer 0 Common Stock 2025-11-17 4 S 0 238 14.05 D 269343 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. /s/ Kyle Piskel 2025-11-18