Information needed to administer the federal SSI program resides on SSA's Supplemental Security Record (SSR) file, which in December 2001 contained records for approximately 6.4 million individuals who received a federal SSI benefit for that month. The SSI Public-Use Microdata File contains an extract of data fields from the SSR and consists of a 5 % random, representative sample of persons who received a federal SSI benefit in December 2001. This file contains approximately 320,000 records with 13 data fields on each record.
