X0306 4 2021-05-11 0 0001478320 Adaptive Biotechnologies Corp ADPT 0001524314 Cohen Chad M C/O ADAPTIVE BIOTECHNOLOGIES CORP. SUITE 200 SEATTLE WA 98102 0 1 0 0 Chief Financial Officer Common Stock 2021-05-11 4 M 0 10000 6.55 A 31604 D Common Stock 2021-05-11 4 S 0 2969 30.81 D 28635 D Common Stock 2021-05-11 4 S 0 7031 31.84 D 21604 D Common Stock 2021-05-12 4 M 0 10000 6.55 A 31604 D Common Stock 2021-05-12 4 S 0 10000 32.63 D 21604 D Stock Option (Right to Buy) 6.55 2021-05-11 4 M 0 10000 0.00 D 2028-02-07 Common Stock 10000 140000 D Stock Option (Right to Buy) 6.55 2021-05-12 4 M 0 10000 0.00 D 2028-02-07 Common Stock 10000 130000 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 16, 2020. The price reported for this transaction is a weighted-average price. The shares were sold in multiple transactions ranging from $30.488 to 31.48, 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. The shares were sold in multiple transactions ranging from $31.52 to 32.12, inclusive. The price reported for this transaction is a weighted-average price. The shares were sold in multiple transactions ranging from $32.21 to 32.82, inclusive. 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 option is fully vested and exercisable. /s/ Chad Cohen by Eric Billings, Attorney-in-Fact 2021-05-13