Elderly migration was measured indirectly on the basis of the proportionate increase in the population aged 65 and older between 1970 and 1975. Using this measure, 173 "high impact counties" were identified. Characteristics of the health care delivery system (medical underservice, physicians, hospital beds) were then examined, as were selected demographic data for these counties. In general, high impact counties were found to have adequate (or better) supplies of physicians and hospital beds to meet national standards. Moreover, there was some evidence that those counties with the greatest impacts were the best served. This research underscores the need for studies focusing on individual areas rather than on grouped data.