International medical graduate physicians in the United States: changes since 1981.

Nearly a quarter of all active U.S. physicians are international medical graduates (IMGs)--physicians trained outside the United States and Canada. We describe changes in characteristics of IMGs from 1981 to 2001 and compare them with their U.S. medical graduate (USMG) counterparts. Since 1981, the leading source countries for IMGs have included India, the Philippines, and Mexico. IMGs were more likely to be generalists and to practice in designated underserved areas than USMGs but slightly less likely to practice in isolated small rural areas and persistent-poverty counties. IMGs are an important source of primary care physicians in rural and underserved areas.