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…
Providers that bill Medicare use codes for patient diagnoses and codes for care, equipment, and medications provided. This articles provides resources to identify the codes used in Medicare claims files.
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.
This article presents the data options available to researchers studying the End-Stage Renal Disease (ESRD) population. 
The purpose of this article is to describe how to use the Medicare managed care enrollment information found in the Medicare Beneficiary Summary File (MBSF) Research Identifiable File (RIF) or Denominator in the Limited Data Set (LDS). Medicare managed care is sometimes also called Medicare Advantage, Medicare Part C or Medicare + Choice.
When importing Medicare cost reports into Microsoft Access, data users should use the “link specifications” option to ensure that each variable imports with the correct data type.
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 outlines the provider identification numbers that are available in the MAX files and options for linking to the Medicare Provider Number.
Occasionally researchers need to obtain identifiable data for MCBS participants, including claims data outside MCBS participation (i.e. before or after the individual participates in the MCBS). This article provides a brief overview of that process.
Researchers who are interested in studying inpatient utilization (e.g. hospital stays) have two options: the Inpatient claims file or the Medicare Provider Analysis and Review (MedPAR) file. It is important to note that the differences between the two files will vary depending on whether a researcher is interested in the Research Identifiable File (RIF) or Limited Data Set (LDS) versions of the two files.
The purpose of this article is to describe what ambulatory surgical centers are and to explain how this provider type differs from other provider types that bill Medicare.
The Medicare Hospital Service Area File is one of the few CMS non-identifiable files that can be opened in Microsoft Excel. The article describes the steps to import the file into Excel.
The purpose of this article is to describe the difference between the two modules available for the MCBS between 1991-2013.