A cancer research training program explored different approaches for staffing their in-person and virtual programs for high school students. The inclusion of undergraduate near-peer mentors had a universal benefit when implemented across in-person and virtual training programs of one- and ten-week durations. Benefits are described for four stakeholder groups: the high school trainees, program staff, scientist partners, and peer mentors themselves. Peer mentors described that their involvement enhanced their own professional development and, for some, drove a new interest in cancer research. Scientist partners described that peer mentors helped translate their work in the virtual environment for high school students. High school trainees reported their sessions with peer mentors to be one of their favorite parts of the program. Interprofessional peer mentors were highly relatable to students and modeled communication and paths in biomedical research. Staff reported that peer mentors supported student engagement during community shadowing sessions, allowing staff to focus on developing the shadowing experiences with partners. The benefit of including peer mentors was substantial from all viewpoints explored. Their intensive inclusion in cancer research training programs supports sustainability and capacity building in biomedical workforce development.