Over the last decade, the primary care specialties have experienced an ebb and flow in popularity. A description of the future primary care workforce may inform planning for the health care needs of our population. To describe characteristics of physicians training in primary care specialties over the past 9 years and to monitor trends in the characteristics of the entire residency population. Descriptive survey study of the National GME Census, conducted by the American Medical Association and Association of American Medical Colleges, which jointly surveyed 8246 allopathic graduate medical education (GME) programs during the academic year 2004-2005 about active, transferred, and graduated residents, as well as about program characteristics. Program directors confirmed the status of 97.3% of active residents. The accompanying program survey was completed by 7163 (87%) of the program directors. General trends in the numbers and characteristics of all residents, fellows, and training programs, with specific trends for residents and fellows training in the primary care specialties and subspecialties over the past 9 years. The census counted 101 291 physicians-in-training during the 2004-2005 academic year, the largest number ever recorded by this survey. The number of osteopathic medical school graduates (DOs) in allopathic GME decreased from 5838 in 2003-2004 to 5675, following many years of annual increases. The number of residents in primary care specialties reached a peak in the mid 1990s. The number of family medicine residents who are graduates of US allopathic medical schools (USMDs) has fallen from 8232 (77.6%) in 1998-1999 to 4848 (51.7%) in 2004-2005. The number of primary care residents who are graduates of foreign medical schools and US citizens (USIMGs) nearly doubled between 1995-1996 (n = 1768) and 2004-2005 (n = 3304). The number of USIMGs training in internal medicine or pediatrics subspecialties increased by 45.7% between 1995-1996 (n = 622) and 2004-2005 (n = 906). The number of pediatric subspecialty fellows grew 55.7%, mostly because of the near doubling of USMDs, from 813 to 1617. More than half of primary care residents are women (52.5%). All primary care specialties and subspecialties experienced gains in the proportion of female residents, with the greatest in obstetrics/gynecology, which increased by 28.7% (57.9% in 1995-1996 vs 74.5% in 2004-2005). An increasing proportion of physicians are pursuing subspecialty training, while the number in primary care specialties has leveled off. Trends in GME suggest that the primary care medical workforce of the future will include more women, more IMGs, and more DOs.