We used detailed information from 16 states to determine the distance that residents of outlying areas (or of towns of less than 25,000, outside metropolitan areas) must travel to receive various types of medical care. For both 1970 and 1979, we found that approximately 80 per cent of such residents lived within 10 miles' driving distance of some physician and 98 per cent lived within 25 miles. Most of the remaining 2 per cent lived in areas so sparsely settled that physicians will not find them economically attractive as practice locations. During the 1970s, the distance of members of the studied population from medical and surgical specialists was substantially reduced. The greatest improvement occurred for the specialties that had the largest percentage increase in their numbers. As the physician pool expands further during the 1980s, geographic access to specialty care for rural and small-town residents should show a further notable improvement. However, this improvement may not suffice to meet what some consider the "medical need" of those who are geographically isolated or economically deprived.