Updated research request forms and data security approval requirement effective 4/24/23
The 3-digit social security administration (SSA) standard county code of a beneficiary's residence.
CMS enrollment data is obtained from the source CMS Common Medicare Environment (CME) data.
A listing of county codes can be found on the US Census website; also CMS has corebased statistical area (CBSA) crosswalk files available on their website, which include state and county SSA codes.
Source: CMS Encounter Data System (EDS)