The Nuclear Regulatory Commission (NRC) is amending its regulations governing the medical use of byproduct material to change its requirements for recognition of specialty boards whose certifications may be used to demonstrate the adequacy of the training and experience of individuals to serve as radiation safety officers, authorized medical physicists, authorized nuclear pharmacists, or authorized users. The final rule also revises the requirements for demonstrating the adequacy of training and experience for pathways other than the board certification pathway. This final rule grants, in part, a petition for rulemaking submitted by the Organization of Agreement States (PRM-35-17) and completes action on the petition.