Knowledgebase

ResDAC has developed over 100 articles that cover topics ranging from the CMS data request process through using the data for a study. CMS has developed additional resources, including TAF data quality briefs and TAF data quality state snapshots, examining the quality of the Medicaid data.
Introductory
Articles
CMS offers files from aggregate data to individual person level data. This article describes the differences between the aggregate, public use files, the limited data sets,…
This article describes the Federal Regulations that govern the release of CMS data for research.
The purpose of this article is to identify 1) common strengths of Medicare and Medicaid administrative data and 2)  broad limitations for researchers to consider when…
To describe the CMS cell size suppression policy and provide examples of common scenarios and possible options.
There are many different provider variables in the Medicare Fee-for-Service (FFS) Claims and Encounter data. Researchers are often interested in the performing NPI and/or the facility CCN or organizational NPI, but other variables are sometimes useful. The purpose of this article is to help you understand these variables and we present the completeness of these data to assist researchers who are designing research studies using Medicare FFS claims and Encounter data.
ResDAC faculty and Technical Advisors (TAs) are frequently asked to recommend a best algorithm for identifying cases, treatments, outcomes, etc.In the experience of ResDAC faculty, there is never a single best algorithm that meets all situations. There is often ambiguity with a mix of clear “yes”, clear “no” and a group in the middle (the “uncertain” ones). How exactly we define the three groups and what we do with that “uncertain” group depends on a variety of factors.
The purpose of this article is to provide an overview of the Centers for Medicare & Medicaid Services' (CMS') payment standardization process, as well as provide methodological documentation that explains how the standardized claim payment amounts for Medicare Part A, Part B, and Part D claims are calculated.
Medicare managed care enrollment has fluctuated over the years and is a frequently requested statistic. Often researchers are interested in penetration rates or the percentage of Medicare beneficiaries enrolled in a Medicare managed care plan. These plans are also referred to as Medicare Part C, Medicare Advantage (MA), or Medicare Health Maintenance Organizations (HMOs).
This article provides a link and overview of the document on finder and crosswalk files written by the CMS data distributor, HealthAPT.
Doctoral students may request CMS data for their dissertation project. Students should consider several factors when deciding which type of data to use. This article presents considerations and resources for students interested to request CMS Research identifiable data.
States that have "Opted-In" to data sharing under the State Research request process are required to submit quarterly logs to CMS. 
The Centers for Medicare & Medicaid Services (CMS) seeks to ensure the protection of CMS data disclosed to external organizations for research purposes. To accomplish this, CMS has developed the Data Privacy Safeguard Program (DPSP). The DPSP reflects the CMS priorities to both improve data stewardship and to protect the privacy and security of CMS research identifiable files (RIF) that are made available for conducting important research studies.
Beneficiary death information is available in several of the Medicare enrollment files. Limited death information is also found in other files, such as the MedPAR. This article describes the variables found in each.
To describe the CMS policy that prohibits non-US based researchers from accessing identifiable CMS data (RIF and LDS) and provide examples of common scenarios.
Along with claims at the individual beneficiary (single enrollee/provider/visit) level, state Medicaid programs also submit service tracking claims which record lump sum payments to providers or managed care plans. These data are a new enhancement to the TAF RIF, and researchers have the option of requesting these claims along with TAF claims data. This article describes service tracking claims in TAF RIF data and considerations for researchers.