X0206 3 2020-02-05 0 0001745999 Beam Therapeutics Inc. BEAM 0001786304 Evans John M. C/O BEAM THERAPEUTICS INC. 26 LANDSDOWNE STREET CAMBRIDGE MA 02139 1 1 0 0 CEO Common Stock 878257 D Common Stock 223000 I By John M. Evans, III 2018 Irrevocable Trust Stock Option (Right to Buy) 1.03 2028-07-13 Common Stock 517345 D Stock Option (Right to Buy) 7.22 2029-05-17 Common Stock 223000 D Includes 855,957 restricted stock units granted to the Reporting Person under the Issuer's 2017 Stock Option and Grant Plan. Each restricted stock unit represents the contingent right to receive one share of Common Stock. The restricted stock units vest over a period of 48 months, provided that the Reporting Person remains in continuous service with the Issuer through each vesting date. The option vested as to 25% of the first anniversary of the of the vesting commencement date, January 8, 2018, and at a rate of 2.78% each month thereafter until the option is fully vested. The option vests as to 25% of the first anniversary of the of the vesting commencement date, October 1, 2019, and at a rate of 2.78% each month thereafter until the option is fully vested. Exhibit List: Exhibit 24 - Power of Attorney By: /s/ Christine Bellon, Attorney-in-Fact 2020-02-05