This document discusses post-marketing requirements (PMRs) and post-marketing commitments (PMCs) required of drug sponsors after FDA approval. PMRs are studies required by regulation, while PMCs are studies agreed upon between the sponsor and FDA but not required. Sponsors must periodically report on the status of PMRs and PMCs, with certain details like enrollment required for clinical trials. The FDA provides guidance and websites for sponsors to report and check the status of post-marketing studies.