There is a confluence of interests between those who acquire a disability and those who do so through the process of aging. This chart from "U.S. Census Bureau Report on Americans with Disabilities: 1994-95" summarizes.

Source: U.S. Census Bureau Report on Americans with Disabilities: 1994-95, P70-61 (August 1997)
Based on Survey of Income and Program Participation, Oct. 1994-Jan. 1995