TScan Therapeutics, Inc.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. On September 8, 2026, the Compensation Committee of the Board of Directors (the “Board”) of TScan Therapeutics, Inc. (the “Company”) approved a retention program designed to retain the employees required to support the Company, including a key employee retention program (the “Retention Program”) that provides for cash awards and the potential future grant of equity-based awards to certain key employees of the Company, including Gavin MacBeath, Ph. D., the Company’s Chief Executive Officer, and Zoran Zdraveski, JD, Ph. D., the Company’s Chief Legal and Strategy Officer. Each of the equity-based awards are to be made under the Company’s Amended and Restated 2021 Equity Incentive Plan (the “2021 Plan”). Under the Retention Program, Dr. MacBeath and Dr. Zdraveski will receive (i) cash awards of $822,000 and $416,000, respectively, with (A) one-third (1/3) of the first half of such cash awards to be paid in November 2026 and the remaining two-thirds (2/3) of the first half to be paid in February 2027, and (B) the second half of such cash award to be paid upon achievement of certain milestones relating to the advancement of the Company’s in vivo solid tumor program (the “Clinical Milestone”), and (ii) equity-based awards of 2,400,000 restricted stock units (“RSUs”) and 1,050,000 RSUs, respectively, to be granted under the 2021 Plan, with one-third (1/3) of such RSUs scheduled to vest upon achievement of a certain financing milestone (the “Financing Milestone”) and the remaining two-thirds (2/3) vesting in equal installments on the first and second anniversaries of the Financing Milestone, in each case subject to continued service with the Company through the applicable vesting dates and the terms of the 2021 Plan and the applicable award agreement.