X0609 4 2026-03-31 0001624322 Business First Bancshares, Inc. BFST 0001841232 McDonald Warren false 500 LAUREL STREET, SUITE 101 BATON ROUGE LA 70801 1 EVP & Chief Credit Officer 0 COMMON STOCK 2026-03-31 4 F 0 1158 27.04 D 14195 D Restricted Stock Units 0.0000 Common Stock 9273 9273 D Includes: (a) 2,584 time-based restricted stock units granted on December 12, 2024, which will vest in two substantially equal installments on the second and third anniversary of the issuance date; (b) 2,715 time-based restricted stock units granted to the reporting person on March 1, 2025, which will vest in two substantially equal installments on the second and third anniversary of the issuance date; and (c) 3,974 time-based restricted stock units granted to the reporting person on March 2, 2026, which will vest in three substantially equal installments on the first, second, and third anniversary of the issuance date. /s/ Heather Roemer, as attorney-in-fact for Warren McDonald 2026-04-02