X0609 4 2026-03-31 0001624322 Business First Bancshares, Inc. BFST 0001734795 MELVILLE DAVID R. III false 500 LAUREL STREET, SUITE 101 BATON ROUGE LA 70801 1 1 President and CEO 0 COMMON STOCK 2026-03-31 4 F 0 4279 27.04 D 208902 D Restricted Stock Units 0.0000 Common Stock 37346 37346 D Includes units of the employer stock fund through the issuer's 401(k) plan equivalent to approximately 13,786 shares of common stock of the issuer and 96,288 pledged shares of common stock of the issuer. Includes: (a) 10,028 time-based restricted stock units granted to the reporting person on December 12, 2024, which will vest in two substantially equal installments on the second and third anniversary of the issuance date; (b) 10,917 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; (c) 3,280 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; and (d) 13,121 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 David R. Melville III 2026-04-02