Migration of physicians from one specialty to another. A longitudinal study of US medical school graduates.

To demonstrate the extent to which physicians change their specialty, randomized samples of the graduating classes of 1960, 1964, and 1968 were studied with respect to their self-designated specialties in 1971 and 1976. Of the 2,046 physicians in the three samples, 333 (16%) changed their specialty between 1971 and 1976. It was 8% for the 1960 cohort, 11% for 1964, and 29% for 1968. Of all the changes, 78% were from one specialty practice to another or back to a formal residency in a different specialty; 22% changed from one specialty residency to either practice or another residency in a different specialty. Between 1971 and 1976, a total of 127 (16%) of 783 primary care physicians changed their specialty. The magnitude of this change must be considered in planning for distribution of physicians by specialty.