Despite the ever-present risk of a critical imbalance in the physician workforce total numbers and specialty distribution, no systematic planning mechanism is in place. Furthermore, the length of training for graduate medical education (GME) precludes timely rectification of imbalances. We report GME activities collected in the American Medical Association Annual Survey of Graduate Medical Education Programs for 1998-1999, along with trends during the last 3 to 6 years. These data initially suggest that little has changed during the past several years; however, on closer examination, small but significant changes during the past 2 years may have serious consequences if continued. The total number of resident physicians, which has been constant during the last several years, decreased in 1998 by 760 from the previous year, while the number of programs continues to increase (6.1% since 1993). The number of US medical graduates entering GME programs remained stable during the last 6 years, the number of osteopathic graduates entering GME increased by 55.7%, and the number of international medical graduates (IMGs) entering GME continued to drop (down 13.2% since 1993). More IMGs tend to pursue additional training than do US graduates (in 1997, 32.9% vs 23.6%). Because IMGs are remaining in GME programs for longer periods, the total number of IMGs has not yet reflected significant change. About 62% of IMGs now entering GME training are either US citizens or permanent residents; ethnic minority residents are not decreasing in numbers as some predicted; and for the first time in the past 5 years, the primary care specialties have ceased their persistent growth. Toward the end of GME, the number of residents leaving programs before completion increased by 5.7% during the last 3 years. While some of these changes may be ascribed to reduced GME funding through the Balanced Budget Act of 1997, other factors clearly are at play. To anticipate future changes in the physician workforce, these factors should be identified to permit them to be monitored and modified as needed.