X0306 4 2020-08-13 0001180145 Cardiovascular Systems Inc CSII 0001781460 Hastings John M. 1225 OLD HIGHWAY 8 NW ST. PAUL MN 55112 0 1 0 0 VP Manufacturing & Operations Common Stock 2020-08-13 4 F 0 718 31.11 D 45936 D The reporting person has elected to satisfy his tax withholding obligation in connection with the vesting of a prior restricted stock grant by directing the Issuer to withhold shares otherwise issuable upon vesting of the previously reported grant. /s/ Amanda Lorentz as Attorney-in-Fact for John M. Hastings pursuant to Power of Attorney previously filed. 2020-08-17