Over the years, the SSDI program has undergone several changes and expansions. In 1965, the
program was extended to cover individuals under the age of 65, and in 1972, the Supplemental Security
Income (SSI) program was established to provide financial assistance to disabled individuals who were
not covered under the DI program.

In the 1980s and 1990s, there were a number of reforms to the SSDI program in an effort to improve
efficiency and reduce fraud. These reforms included stricter eligibility requirements and the
implementation of a medical vocational allowance, which allowed individuals to receive benefits if they
were unable to work in their previous occupation due to a disability, but could potentially work in a
different occupation.