The U.S. Food and Drug Administration has finalized guidance explaining how it determines whether prescription drug products are therapeutically equivalent—an evaluation that can help pharmacists, prescribers and state agencies determine when an approved generic can be substituted for another version of the same drug.
The FDA announced the final “Evaluation of Therapeutic Equivalence” guidance in August 2026, completing a process that began with draft guidance issued in July 2022. The agency says the document explains its current thinking about therapeutic equivalence evaluations and the codes used to communicate those determinations.
