Social Security Disability Insurance (DI) is the nation’s most important public support for the working-age population with disabilities. The health of this population is a key driver of enrollment and spending in the DI program and the related Supplemental Security Income (SSI) program. Several studies have found that in recent years some dimensions of health among those approaching retirement age have worsened. This study addresses the question of what these recent health trends portend for the future of federal disability programs. Using data from two nationally representative surveys, this study examines trends in chronic disease, physical limitation, and difficulty with activities of daily living (ADL) since the mid-1990s and confirms that trends in many measures do indeed point to worsening health. Based on an analysis of the effects of all measures on DI/SSI application and award probabilities, we constructed indices combining individual health indicators into a smaller number of indices based on their relevance to rates of application and award. While all health variables have strong statistical relationship to DI/SSI behavior, we find that the weighted indices based on trends in diagnoses of chronic illness point to larger increases in demand for disability programs than do indices based on physical limitations and ADL difficulty. If capacity for work is most directly related to measures of physical limitation, and chronic diseases have their effect largely through those limitations, our findings suggest perhaps less alarm about the future demand for DI and SSI benefits than recent studies showing worsening health might generate.