International medical graduates (IMGs) represent a large proportion of the population entering graduate medical education (GME) programs. Many of these internationally trained physicians go on to practice medicine in the United States. To be eligible for GME, IMGs must be certified by the Educational Commission for Foreign Medical Graduates (ECFMG). The number of certificates issued by the ECFMG has varied over time and historically has exceeded the number of available training positions. More detailed longitudinal analyses are required to better understand the interwoven issues of physician supply, consumers' needs, and the role of IMGs in the U.S. health care system.