OBJECTIVE Because of the size and growth of the international medical graduate (IMG) contribution to graduate medical education (GME) in the United States, and subsequently to the US physician workforce, it is essential to understand the demographics and patterns of IMG training and practice as well as the routes of entry into the United States. METHODS Published data from the American Medical Association, the American Osteopathic Association, and the Association of American Medical Colleges; tabular runs of county-level data contained on the Bureau of Health Professions' Area Resource File. RESULTS The majority of IMGs who participate in GME in the United States ultimately enter US practices. A significant proportion of exchange visitors eventually enter into permanent practice in the United States, contrary to the intent of the J-1 visa-based GME training as an international educational exchange program. International medical graduates gravitate toward initial residency programs in internal medicine and pediatrics, many of which have unfilled positions; however, IMGs subspecialize at a disproportionately high rate, reducing their net contribution to the generalist pool. Patterns of ultimate practice location of IMGs parallel the patterns of US medical graduates (USMGs). CONCLUSIONS In recent years, participation of IMGs in GME and practice has increased significantly. Most IMGs in GME are not exchange visitors, but are either permanent residents or US citizens. Patterns of specialization and location of IMGs ultimately mirror those of USMGs. National IMG policy must be examined in light of the projected surplus of physicians in the United States. The best option for long-term control of the number of physicians in practice, USMG or IMG, is a system of specifying the number of GME positions nationally.