X0306 4 2021-02-01 0001624322 Business First Bancshares, Inc. BFST 0001841232 McDonald Warren 500 LAUREL STREET, SUITE 101 BATON ROUGE LA 70801 1 Chief Credit Officer COMMON STOCK 2020-02-01 4 A 0 1931 20.70 A 11068 D Reflects the grant of restricted stock to reporting person. The terms of the restricted stock grant are described in footnote 2 below. Includes (a) 538 shares of unvested restricted stock granted on 3/31/2019 that will vest on 3/31/2021, (b) 931 shares of unvested restricted stock granted on 2/1/2020, 459 of which will vest on 3/31/2021 and 472 of which will vest of 3/31/2022, (c)1,931 shares of unvested restricted stock granted on 2/1/2021, 637 shares of which will vest on each of 3/31/2021 and 3/31/2022 and the remaining 657 shares will vest on 3/31/2023. Under the terms of the relevant restricted stock grants, the reported shares of unvested restricted stock are subject to forfeiture upon the occurrence of certain events. /s/ Heather Roemer, as attorney-in-fact for Warren McDonald 2021-02-03