X0508 4 2025-06-18 0001287098 MAXCYTE, INC. MXCT 0001284839 BALTHROP PATRICK J C/O MAXCYTE, INC. 9713 KEY WEST AVENUE, SUITE 400 ROCKVILLE MD 20850 true false Common Stock 2025-06-18 4 A 0 29210 0 A 50577 D Stock Option (right to buy) 2.11 2025-06-18 4 A 0 50790 0 A 2035-06-17 Common Stock 50790 50790 D These shares represent restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. This annual grant was made pursuant to the Issuer's Equity Grant Policy for non-employee directors. The shares underlying this grant vest on June 18, 2026, subject to the reporting person's continuous service as of such vesting date. Exhibit List: Exhibit 24 - Power of Attorney /s/ David Sandoval, Attorney-in-Fact 2025-06-23