A 9-year follow-up study of a national probability sample (n = 865) of foreign medical graduates (FMGs) and United States medical graduates (USMGs) who were house officers in United States hospitals in 1973-1974 reveals that more than three fourths of the alien FMGs were located in the United States in 1983. FMGs were distributed disproportionately across United States census regions (P < 0.001), specialty areas (P = 0.071), and type of position (P = 0.059). Neither the switching of specialty areas nor the changing among United States census regions was significantly different for FMGs and USMGs. Census regions with net gains of FMGs over the 9-year period included the Pacific, South Atlantic, and West South Central regions, areas with either proportionately higher 1973-1974 USMG concentrations or net USMG gains. The results suggest a gradual assimilation of FMGs into the American medical system from an initial position different than that of USMGs