As the supply of physicians grew during the 1970s, medical and surgical specialists diffused into smaller communities. In 1979, nearly every town with a population of more than 2,500 had ready access to a physician. The overall pattern of physician distribution was quite similar in the four disparate geographic regions chosen for study. The data strongly suggest that competitive forces play a major role in determining where physicians choose to practice. As the pool of physicians expands during the 1980s, a wide range of services will become increasingly available to populations outside metropolitan areas. The methods developed here provide important tool for evaluating and shaping health manpower policy.