ICD-10 codes for stroke: I60-I69. Age-adjusted death rates for adults 35 years and older were calculated using the 2000 U.S. standard population and are displayed by county per 100,000 total population. Rates were spatially smoothed to enhance the stability of rates in counties with small populations by using a spatial moving average. Deaths (numerators) and population counts (person–year denominators) for each county were combined with the deaths and population counts of the immediate neighboring counties (i.e., contiguous counties) and then divided to produce an average rate. A county was determined to have insufficient data for the display of the death rate if the total number of deaths in that county plus its neighbors was fewer than 20 during the specified time period or if the population count was less than 5 during the specified time period. For the contiguous U.S., we used an Albers conic equal area projection; for Alaska, we used a Miller’s Cylindrical projection; and for Hawaii, we used geographic coordinates. Alaska and Hawaii are not in proper geographic scale relative to the continental U.S.