There are wide disparities in health across the US population. The identification of geographic health priority areas for Medicare could inform efforts to eliminate health disparities and improve health care. In a sample of 3,282 counties with more than 73 million unique Medicare beneficiaries in the period 1999–2014, we identified geographical areas—“hot spots”—with persistently higher adjusted mortality rates for older adults compared with the rest of the country. During the study period, the risk-standardized mortality rates decreased from 5.52 percent to 4.61 percent (a 0.91-percentage-point change) for the priority areas and from 5.16 percent to 4.11 percent (a 1.05-percentage-point change) for other areas. Faced with decisions surrounding allocation of scarce resources and marked geographic disparities, the identification and prioritization of hot spots may be one way to eliminate disparities and improve health care.