Relatively little is know about the implications for Medicare spending of downward trends in old age disability in the United States between the mid-1980s and the end of the century. This is in part because uncertainty persists about the extent to which the aggregate disability declines reflect improvements in health versus improvements in the technology, service, and physical environment. This study examines Medicare spending and utilization that occurred over the period of declining disability between 1984 and 1999 and how it differed from what might have been expected had disability not changed and discusses implications for the relationship between disability, Medicare spending, and health. Projections are developed under various assumptions about how disability and spending are likely to change over the over the next several years.