Adaptive Biotechnologies Corp

Under the supervision and with the participation of our management, including our chief executive officer and chief financial officer, we evaluated the effectiveness of the design and operation of our disclosure controls and procedures pursuant to Rule 13a-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) as of the end of the period covered by this report. Based on that evaluation, our chief executive officer and chief financial officer have concluded that our disclosure controls and procedures were effective as of September 30, 2025. There was not any change in our internal control over financial reporting (as such term is defined in Rule 13a-15(f) under the Exchange Act) during the three months ended September 30, 2025 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.