This file contains Protected Identification Keys (PIK) that link Social Security Administration (SSA) Supplemental Security Record (SSR) to the respondents in the internal Current Population Survey Annual
Social and Economic Supplement (CPS ASEC) [formerly known as Current Population Survey (CPS) March Supplement] microdata files. The Supplemental Security Record (SSR) is SSA's main file to track who is receiving Supplemental Security Income (SSI) benefits and the monthly benefit amounts payable.
