The Residency Program in Social Medicine at Montefiore Medical Center is a collaborative, integrated training program for primary care pediatricians, internists, and family physicians within one interdisciplinary organization. Since 1970 we have trained more than 200 physicians, prepared them for board certification in their specialty, emphasized the psychosocial aspects and social determinants of health and illness, and shared a faculty, curriculum, and commitment to provide medical care for inner-city, underserved populations. We discuss the program's history and curriculum, administrative and academic structure, shared "crosstrack faculty units (psychosocial; social medicine; and research, education, and evaluation), and graduates' practice outcomes. The interdisciplinary character of the Residency Program in Social Medicine helps physicians successfully serve the underserved and exemplifies that interdisciplinary medical education succeeds when interdisciplinary health care teams are organized for optimal patient care. Only the federal government has the perspective and power to foster more interdisciplinary collaboration and strengthen primary care education in a period of shrinking resources.