A physician workforce for the 21st century.

Medicine is entering an unprecedented era of provider abundance, including both physician and nonphysician providers. Over the next several decades, the projected number of primary care physicians will be more than adequate to meet national needs, although there is no assurance that any number of physicians will create an equitable distribution. At the same time, a growing surplus of specialists is projected. A balanced abundance in both primary care and specialty medicine will continue if approximately 33% of first-year residents ultimately practice primary care and 67% become specialists. In contrast, a shift to 50:50, as has been proposed by the Committee on Graduate Medical Education and others, will lead to a superabundance in primary care and a potential deficiency in specialty medicine later in the 21st century. Under either scenario, maintaining balance will be aided by those physicians with sufficient generalist skills to enable them to practice at the interface of primary care and specialty medicine, the domain of "middle care." The nation will be well served by educational policy that imparts such generalist expertise to medical students and that creates a workforce of highly skilled physicians capable of caring for patients in the technologically advanced clinical environment of the future.