CMS Medicare Geographic Data and FIPS Codes

The Centers for Medicare & Medicaid Services (CMS) publishes an extensive array of geographic data products covering Medicare and Medicaid enrollment, utilization, spending, and quality metrics. For public health researchers, health economists, and policy analysts, CMS data is essential — and nearly all of it is published at the county level using 5-digit FIPS codes. Our federal data guide includes CMS alongside the EPA, HUD, and other major agencies.

The CMS Geographic Variation Public Use File (GV PUF) is one of the most comprehensive county-level datasets available, covering Medicare fee-for-service spending, utilization, and beneficiary characteristics for every county in the US. Each row represents one county in one year, identified by its 5-digit FIPS code. Standard metrics include total Medicare spending per beneficiary, hospital readmission rates, chronic condition prevalence, and preventive service utilization rates.

The Dartmouth Atlas of Health Care, while not a CMS product directly, is built on CMS data and uses Hospital Referral Regions (HRRs) and Hospital Service Areas (HSAs) — geographic units defined by patient flow rather than political boundaries. HRRs and HSAs have their own codes (not standard FIPS) and don't align with county boundaries. If you need to join Dartmouth Atlas data with standard FIPS-based datasets, you'll need a crosswalk from HSA/HRR to county FIPS.

For geographic analysis of healthcare access and outcomes, a common workflow combines CMS county-level utilization data with Census ACS socioeconomic variables and HRSA (Health Resources and Services Administration) provider shortage area designations — all joined on 5-digit county FIPS codes. Browse county profiles like Harris County, TX (48201) or Cook County, IL (17031) for geographic context, and use the FIPS search to identify the codes you need.