Tufts’ Building Diversity in Biomedical Sciences (BDBS) Program builds on a 30-year tradition of excellence in preparing students from under-represented groups (URG) for careers in the biomedical workforce. BDBS has an outstanding history of providing immersive summer research experiences in areas of NHLBI focus. Based at Tufts University’s Graduate School of Biomedical Sciences (GSBS), BDBS has trained 220 students in the past 15 years, all of whom have either completed or are still enrolled in undergraduate training. Among those who have completed college, 129 have entered health-science-related graduate programs. Another 74 have completed their degrees and 51 remain enrolled, while only four have left the programs without a degree. In the coming period, we will build on this high record of success using insights from current education literature on successful training approaches for URG students in the sciences, as well as formative and summative evaluations and other surveys. Specifically, BDBS will build on the principle that independent research in an inclusive welcoming community improves student self-confidence, persistence and success in a science major, and overall interest in pursuing a research career. The core of our program is a rigorous and intensive 10-week mentored summer lab experience focused on NHLBI research. A merger of Tufts Medical School with its major clinical affiliate permits us to increase the number of preceptors – especially those in NHLBI research (from 40 to 52), and we provide them with culturally-aware mentor training. These preceptors are clustered into seven areas of focus, such that trainees can further learn the value of interdisciplinary collaboration in small groups. Their lab experience is complemented by Skills Workshops for training in scientific skills that enhance self- confidence and identity as a scientist. Lunch with a Professor and Meet the Scientist introduce trainees to the breadth of biomedical science careers and provide career models through interactions with faculty (beyond their own preceptor), GSBS alumni who are biomedical leaders, BDBS alumni, graduate students, post- baccalaureate, and postdoctoral scholars. BDBS trainees are housed together close to labs and public transportation at the Tufts University Medical School residence, building their cohort community, while social events that include GSBS students, faculty and alumni provide a diverse and welcoming community (25% of our PhD students are from URG compared to 11% in 2018). A novel aspect of our social events are our STEAM-based activities (STEM+Art to inspire our trainees to creative thinking), taking advantage of the Tufts School of the Museum of Fine Arts and an outreach program for near-peer mentoring. By achieving our aims, BDBS gives trainees the skills and confidence needed to persist and compete effectively for advanced training positions, and eventually to assume leadership roles in the biomedical workforce. Our record ...