Classroom studies of peer-led teaching and mentoring report benefits for students both as teachers and learners. Such benefits include both improved content mastery and personal and professional development. While benefits of peer-led teaching in the clinical setting have been well characterized among other health professions, less is known within undergraduate medical education. In this study, we explored medical students' perceptions and experiences relevant to peer teaching and mentoring in outpatient clinical clerkships. Third-year medical students enrolled in two different longitudinal primary care clerkships, Education Centered Medical Home (ECMH) or Individual Preceptorship (IP), participated in semi-structured interviews in 2018. Students were asked to describe their peer teaching experiences during the clerkship and to reflect on their experiences serving as role models or mentors. We analyzed transcripts utilizing a two-cycle team-based inductive approach. Thirty-three students completed interviews. We derived three main themes: (1) diversity of peer teaching and mentoring opportunities, (2) transitioning one's role from learner to teacher, and (3) personal and professional development. While participants from both clerkships participated in peer teaching and mentoring experiences, ECMH students described more opportunities to interact with students across all years of medical school training, noting that "getting that guidance and in turn being able to teach is a valuable experience." ECMH students further perceived the responsibility of creating a comfortable learning environment for others. Students from both clerkships reflected on 'learning through teaching,' that teaching served as a reaffirmation of the knowledge they gained, and that teaching experience contributed to their personal and professional growth. Students perceived their participation in peer teaching and mentoring experiences in the clinical setting as contributing positively to personal and professional development. Students from both clerkships reflected on their teaching and mentoring opportunities as a facilitator of growth in their own teaching skills; ECMH students further described a heightened sense of self-confidence and fulfillment. These findings highlight the importance of creating learning environments that foster peer teaching and mentoring, as such opportunities may lead to further growth as a learner and as a physician.