Getting Started with CMS Data

The information provided below will give new users a crash course in selecting, requesting, and analyzing CMS data files. ResDAC's Technical Advisors are available to answer any remaining questions you might have.

Is CMS data right for me?

Medicare and Medicaid administrative data can be used for several types of analyses. To name a few, past research using CMS data has focused on:

  • Factors influencing hospitalizations among the elderly
  • The effect of health reform on Medicare utilization rates
  • Geographical variation in incidence and outcomes of beneficiaries with chronic conditions
  • Cost-effectiveness analysis of clinical procedures

Review our Knowledgebase article that outlines the strengths and limitations of Medicare and Medicaid administrative data for use in research.

To review publications containing analysis of Medicare and Medicaid data, search PubMed.

Which files should I request?

There are numerous CMS data files available to researchers and deciding which file(s) are right for you can be challenging. To start, we recommend familiarizing yourself with the ways in which data files can be categorized. Our website and organize many of the available data files by Privacy Level:
  1. Research Identifiable Files (RIF)

    This is the most restricted level, because files are patient-specific and contain identifiable information. RIF data can only be obtained for research purposes.
  2. Limited Data Sets (LDS)

    LDS files may be patient-specific and also contain identifiable information. However, many of the identifiable fields are ranged or encrypted.
  3. Public Use Files (PUF)/Non-identifiable Files

    This is the least restricted level, because files contain either aggregated data or non-identifiable patient-specific information. These files are in the public domain and can be accessed by anyone.

You can also search the ResDAC website for data files by Program (Medicare or Medicaid) and by Category (such as Beneficiary Enrollment & Demographics, Beneficiary Surveys, or Medicaid Utilization).

If you already know the name of the file you are interested in requesting, see our Data File Directory. Once you find a file that sounds promising, you can review the data documentation on our website, including a list of the variables contained in the file, and variable descriptions, code tables, and limitations.

Review our CMS Data Availability table to find updated availability and estimated release dates for CMS data files.

Have more questions about which file(s) are right for you? Contact us!

What is the cost?

The cost of CMS data can vary greatly depending on several factors:
  • Number of quarters/years
  • File types
  • Cohort size
  • Cohort customization criteria
  • Whether or not you are reusing data under an existing DUA

How to obtain an estimate of the cost of data files

  • Research Identifiable Files (RIF): Pricing for RIF data is not available online. Please contact us for a ballpark estimate over the phone or submit a formal cost estimate request.
  • Limited Data Sets (LDS): To review pricing for LDS files, please visit the LDS Overview Section of the CMS website.
  • Public Use Files (PUF): To review pricing for PUF/Non-Identifiable files, please visit the PUF Overview Section of the CMS website.

How do I obtain CMS data?

To request Research Identifiable Files (RIF), you must submit your application materials to ResDAC for an initial review. A ResDAC Technical Advisor will review your request for accuracy and completeness; we are here to ensure your application for data is as strong as possible when it is submitted to CMS. An overview of the timeline and process for requesting RIF data is presented in this Knowledgebase article.

Depending on the nature of your request, specific request materials will be required. To review the request materials needed for your request, see our RIF Data Request page. If you have specific questions about how to fill out the required documents, refer to these helpful articles:

To request Limited Data Set (LDS) files (other than MCBS or HOS data), you must submit your application materials to CMS directly at ResDAC review is not required for LDS requests (other than MCBS or HOS data). For more information on the process for submission, visit the Limited Data Sets (LDS) section of the CMS website.

To request Public Use Files (PUF)/Non-identifiable Files , you must submit your order to CMS directly. ResDAC review is not required for PUF requests. For more information on the ordering process, visit the Public Use Files (PUF)/Non-identifiable Files section of the CMS website.

Still have questions? Contact us! We would be happy to assist you.

I received the data. What types of support does ResDAC offer?

ResDAC offers several resources to assist you in your research:

  • ResDAC Assistance Desk - ResDAC Technical Advisors are available at no charge to answer questions and assist you in locating additional resources.
  • Free CMS Workshops - Workshops range from introductory courses on Medicare and Medicaid data to more advanced analysis.
  • Data Documentation – Find file record layouts, variable limitations, and variable code tables on our website.
  • Knowledgebase Articles on programming and analysis

I would like to publish my research. Are there any restrictions that apply?


CMS no longer requires review of your manuscript. However, you are still expected to abide by the cell suppression policy outlined in Section 9 of the DUA.