144 0001787359 XXXXXXXX LIVE 0001496323 IGM BIOSCIENCES, INC. 001-39045 325 E MIDDLEFIELD ROAD MOUNTAIN VIEW CA 94043 650-965-7873 Misbah Tahir Officer Common Stock Morgan Stanley Smith Barney LLC

200 W Civic Center Dr., 4th Floor Sandy UT 84070

6612 65789.40 33286205 03/13/2024 NASDAQ Common Stock 03/13/2024 Vesting of Restricted Stock Units - See Remarks Issuer N 6612 03/12/2024 Equity Compensation Y Shares sold to cover tax withholding obligations in connection with the vesting of restricted stock units. 03/13/2024 /s/ Misbah Tahir