Phenomenon: Teaching medical students how to teach is a growing and essential focus of medical education, which has given rise to student teaching programs. Educating medical students on how to teach can improve their own learning and lay the foundation for a professional identity rooted in teaching. Still, medical student-as-teacher (MSAT) programs face numerous obstacles including time constraints, prioritizing curriculum, and determining effective evaluation techniques. The purpose of this scoping review is to map the current landscape of the literature on medical school initiatives designed to train students to teach to describe why medical student teaching programs are started; the benefits and barriers; who teaches them; what content is taught; and how content is delivered. With this new map, the authors aimed to facilitate the growth of new programs and provide a shared knowledge of practices derived from existing programs. Approach: The authors conducted a scoping review, guided by Arksey and O’Malley’s framework, to map the literature of MSAT training programs. Six databases were searched using combinations of keywords and controlled vocabulary terms. Data were charted in duplicate using a collaboratively designed data charting tool. This review builds on the Marton et al. review and includes articles published from 2014 to 2020. Findings: Of the 1,644 manuscripts identified, the full-text of 57 were reviewed, and ultimately 27 were included. Articles included empirical research, synthetic reviews, opinion pieces, and a descriptive study. Analysis focused on modalities for teaching medical students how to teach; content to teach medical students about teaching; benefits and barriers to starting teaching programs; and the value of teaching programs for medical students. Insights: The rapid growth of MSAT programs suggests that this curricular offering is of great interest to the field. Literature shows an increase in evaluative efforts among programs, benefits for students beyond learning to teach, and evidence of effective engagement in medical students’ designing and implementing programs.