Formative assessments can enhance and enrich student learning. Typically, these have been used to provide feedback against end-of-course standards and prepare students for summative assessments of performance or measurement of competence. Here, we present the case for using assessments for learning to encompass a wider range of important outcomes. We discuss 1) the rationale for using assessment for learning; 2) guiding theories of expertise that inform assessment for learning; 3) theoretical and empirical evidence; 4) approaches to rigor and validation; and 5) approaches to implementation at multiple levels of the curriculum. The literature strongly supports the use of assessments as an opportunity to reinforce and enhance learning. Physiology teachers have a wide range of theories, models, and interventions from which to prepare students for retention, application, transfer, and future learning by using assessments.