X0508 4 2025-03-04 0001478320 Adaptive Biotechnologies Corp ADPT 0001229765 GRIFFIN MICHELLE RENEE C/O ADAPTIVE BIOTECHNOLOGIES CORPORATION 1165 EASTLAKE AVENUE EAST SEATTLE WA 98109 1 0 0 0 1 Common Stock 2025-03-04 4 A 0 15394 0 A 67349 D Common Stock 2025-03-06 4 S 0 15664 7.94 D 51685 D Stock Option (right to buy) 8.12 2025-03-04 4 A 0 23726 0 A 2035-03-04 Common Stock 23726 23726 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 18, 2024. The price reported for this transaction is a weighted-average price. The shares were sold in multiple transactions ranging from $7.64 to $8.21, inclusive. The reporting person undertakes to provide to Adaptive Biotechnologies Corporation, any security holder of Adaptive Biotechnologies Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in any footnotes to this Form 4. The option will vest in equal monthly installments over one year from March 4, 2025, subject to continued service as a director through such vesting dates. /s/ Michelle Renee Griffin by Kyle Piskel, Attorney-in-Fact 2025-03-06