X0508 4 2025-11-20 0 0001478320 Adaptive Biotechnologies Corp ADPT 0001780854 BENZENO SHARON C/O ADAPTIVE BIOTECHNOLOGIES CORPORATION 1165 EASTLAKE AVE E SEATTLE WA 98109 0 1 0 0 Chief Commercial Ofc Imm Med 1 Common Stock 2025-11-20 4 M 0 133032 8.46 A 525755 D Common Stock 2025-11-20 4 M 0 68961 12.14 A 594716 D Common Stock 2025-11-20 4 S 0 297925 16.54 D 296791 D Common Stock 2025-11-21 4 M 0 834 6.27 A 297625 D Common Stock 2025-11-21 4 M 0 20834 6.55 A 318459 D Common Stock 2025-11-21 4 M 0 49480 6.55 A 367939 D Common Stock 2025-11-21 4 M 0 34375 7.27 A 402314 D Common Stock 2025-11-21 4 M 0 119809 12.14 A 522123 D Common Stock 2025-11-21 4 M 0 83145 3.99 A 605268 D Common Stock 2025-11-21 4 S 0 308477 16.91 D 296791 D Stock Option (right to buy) 8.46 2025-11-20 4 M 0 133032 0 D 2033-03-06 Common Stock 133032 66517 D Stock Option (right to buy) 12.14 2025-11-20 4 M 0 68961 0 D 2032-03-04 Common Stock 68961 136970 D Stock Option (right to buy) 6.27 2025-11-21 4 M 0 834 0 D 2027-04-25 Common Stock 834 0 D Stock Option (right to buy) 6.55 2025-11-21 4 M 0 20834 0 D 2028-02-07 Common Stock 20834 0 D Stock Option (right to buy) 6.55 2025-11-21 4 M 0 49480 0 D 2028-10-01 Common Stock 49480 0 D Stock Option (right to buy) 7.27 2025-11-21 4 M 0 34375 0 D 2029-02-07 Common Stock 34375 0 D Stock Option (right to buy) 12.14 2025-11-21 4 M 0 119809 0 D 2032-03-04 Common Stock 119809 17161 D Stock Option (right to buy) 3.99 2025-11-21 4 M 0 83145 0 D 2034-03-04 Common Stock 83145 116404 D The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 18, 2025. The options vested with respect to 1/4 of such shares on March 6, 2024, with 1/48 of such shares vesting thereafter at the end of each full month of continuous service until fully vested. The options vested with respect to 1/4 of such shares on March 4, 2023, with 1/48 of such shares vesting thereafter at the end of each full month of continuous service until fully vested. The options vested with respect to 1/4 of such shares on April 19, 2018, with 1/48 of such shares vesting thereafter at the end of each full month of continuous service until fully vested. The options vested with respect to 1/4 of such shares on November 1, 2018, with 1/48 of such shares vesting thereafter at the end of each full month of continuous service until fully vested. The options vested with respect to 1/4 of such shares on October 1, 2019, with 1/48 of such shares vesting thereafter at the end of each full month of continuous service until fully vested. The options vested with respect to 1/4 of such shares on January 1, 2020, with 1/48 of such shares vesting thereafter at the end of each full month of continuous service until fully vested. The options vested with respect to 1/4 of such shares on March 4, 2025, with 1/48 of such shares vesting thereafter at the end of each full month of continuous service until fully vested. The price reported for this transaction is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.50 to $16.90, 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 price reported for this transaction is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.50 to $17.44, 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. /s/ Sharon Benzeno by Kyle Piskel, Attorney-in-Fact 2025-11-24