Traditional underrepresented minority (URM) groups (African Americans, Hispanic Americans, Native Americans) remain underrepresented among physician-scientists. To address the dearth of URM physician-scientists, in 1993 the Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program developed a pipeline program, Gateways to the Laboratory (Gateways), which focuses on increasing the breadth and depth of the URM physician-scientist pipeline by offering an all-encompassing summer research training program which mirrors the life of a physician-scientist. This includes hypothesis-driven research and clinical shadowing opportunities, coupled with weekly career development workshops and extensive multitiered mentoring. Among the 245 alumni who had "graduated" from Gateways as of 2013, 88% have pursued or completed advanced degrees. Among these, 74% completed or are pursuing MD, PhD, or MD-PhD degrees; and 17% completed or are pursuing combined MD-PhD degrees, over one-third of whom are enrolled in the Tri-Institutional MD-PhD Program. Gateways outcomes are compared to other programs with similar missions, which shows that Gateways has been successful at preparing URMs for MD-PhD Programs. The program serves as a model for how to increase the national pool of competitive URM MD-PhD applicants.