This guidance provides recommendations for applicants and FDA review staff on classification categories A, B, C, D, E, and F for original and resubmitted prior approval supplements (hereafter referred to as PAS or supplements) submitted to approved applications under section 351(k) of the Public Health Service Act (PHS Act) (42 U.S.C. 262(k)). The commitment letter associated with the Biosimilar User Fee Amendments of 2022 (BsUFA III) sets forth these supplement classification categories and their associated review performance goals (refer to Section I.A. of the BsUFA III commitment letter).This guidance is intended to help applicants identify the appropriate classification category and review goal date of the supplement being submitted.