Despite increased numbers of medical-school graduates and opportunities for "primary-care" specialty training since the mid-1960's, many believe that the shortage of physicians delivering generalist care will continue through the 1980's. Missing, however, is solid information on the role of physician specialists in providing such care. Two national studies have shown that one of every five Americans now receives continuing general medical care from a specialist physician. Our study suggests that, despite the current shortage of generalist-physician services, continuing specialist participation in primary care will lead to sufficient generalist medical services by the mid-1980's. Whether specialist participation is the most appropriate or cost-effective way to improve access to such care is unclear. However, until this question is resolved, more governmental regulation of graduate medical education may be unwise. Offering all physicains, regardless of specialty, more primary-care experience during residency training might better deal with this aspect of American medical practice.