This study assesses whether the National Health Service Corps's legislated goals to see health improve and health disparities lessen are being met in rural health professional shortage areas for a key population health indicator: age-adjusted mortality. In a descriptive study using a pre-post design with comparison groups, the authors calculated age-adjusted mortality rates at baseline (1981-1983) and follow-up (1996-1998) for the populations of 448 rural whole-county health professional shortage areas arrayed into 3 groups based on the number of study years they were staffed by National Health Service Corps physicians, physician assistants, and nurse practitioners (terms of 1 to 7, 8 to 11, and 12 to 15 years). The authors compared changes over time in age-adjusted mortality rates in the 3 county groups that had National Health Service Corps staffing with rate changes in 172 whole-county rural health professional shortage areas and 772 non-health professional shortage area rural counties that had no National Health Service Corps. At baseline, age-adjusted mortality was higher in all 4 health professional shortage area county groups than in the non-health professional shortage area county group. Age-adjusted mortality rates improved with time in all groups, including health professional shortage area counties both with and without National Health Service Corps support, and non-health professional shortage area counties. Essentially, baseline differences in age-adjusted mortality rates between health professional shortage areas and non-health professional shortage area counties did not diminish with time, whether or not there was National Health Service Corps support. From the early 1980s through the mid-1990s, the National Health Service Corps's goal to see health improve in rural health professional shortage areas was met, but its goal to diminish geographical health disparities was not. Because age-adjusted mortality rates improved in all county groups, the authors conclude that improvement was likely due to a variety of factors, including decreasing poverty and unemployment rates and increasing primary care physician-to-population ratios, to which the National Health Service Corps may have contributed.