Abstract
Introduced over 20 y ago, IACUCs undertaking postapproval monitoring (PAM) of animal research procedures as a means to ensure researcher compliance is now widely used as an oversight tool in laboratory animal research. Through a literature review evaluating the history of PAM in the United States, discussions of controversy surrounding PAM activities, and reflections on how PAM activities are described within the IACUC community, we present an up-to-date and comprehensive classification system for PAM program methodologies that could serve to standardize how such activities are characterized in IACUC policies, communicated to research staff, used in training programs, implemented for the desired impact by individuals involved in animal research oversight, and referenced by regulatory agencies.