This report describes the 10-year outcome of implementing practices that support and foster success of underrepresented students in science, technology, engineering, and math (STEM) graduate training at Brown University. The results show sustained improvements in compositional diversity, retention, and degree attainment of supported students relative to their peers. Among the outcomes is an increase in enrolled student diversity from 19 (35 of 179) to 26% (58 of 223) for historically underrepresented minority (URM) students and an increase in Ph.D. degree attainment from 4 (1 of 25) to 14% (6 of 44) for this group. These achievements follow the introduction and coordination of academic and co-curricular practices through the National Institutes of General Medical Sciences-funded Brown University Initiative to Maximize Student Development (IMSD) Program. At the center of these outcomes is the alignment of IMSD practices with recent diversity initiatives launched by the university. The outcomes described result from long-term commitments to building a culture that includes: (1) development of relationships that serve underrepresented students; (2) provision of a personalized education program of support and skills-based learning that supplements discipline-based research and coursework; and (3) investments in processes that build a culture that values and benefits from diversity. These practices may yield similar outcomes and success for students when applied elsewhere.