CMS Medicare: Public-Use Feasibility Files

NCHS Linked Data

July 17, 2025

Researchers use feasibility files to understand whether restricted-use data will be appropriate for their research.
National Center for Health Statistics (NCHS)-CMS Medicare public-use feasibility files are available to download.
Feasibility files are specific to each NCHS survey and survey-year.

Image shows two swarms of dots, one purple and one green. Each swarm represents a data stream. They are converging.

Overview

Feasibility files help researchers determine whether restricted-use data are appropriate for their needs. They are also helpful when deciding whether to start a Research Data Center (RDC) proposal to access restricted data.

These files provide variables that determine the largest available sample size for each linked file. The National Center for Health Statistics (NCHS) has created public-use feasibility files for Medicare linked data products.

Feasibility files

Each feasibility file is NCHS survey- and survey-year specific. The following information is included on each feasibility study file—

NCHS survey public-use identifier
Survey participant eligibility status for CMS Medicare linkage
Final match status
Other variables indicating which specific CMS Medicare data files are available for each successfully linked survey participant

The feasibility files were prepared for the initial data release in April 2021. The feasibility files have not been updated with information based on the additional files provided in the April 2024 release. Files do not include 2014–2015 fee-for-service claims, prescription drug events, and patient assessments, or 2017–2018 Medicare Advantage encounter records.

The updated data release has no impact on using the feasibility files for estimating maximum available sample size.

Feasibility study files do not contain any specific information about CMS Medicare benefits. Researchers should consider external sources to estimate the number of respondents with a specific condition.