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…
The Medicare cost report files are created by Fiscal Year. The definition used to create the fiscal year files vary depending on the provider type.
This article provides resources for obtaining statistics and reports related to the Medicare and Medicaid programs and their beneficiaries. The following Medicare/Medicaid statistical and summary data resources address some of the most common requests for this type of information. These are by no means exhaustive.
States that have "Opted-In" to data sharing under the State Research request process are required to submit quarterly logs to CMS. 
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.
This article provides a brief overview of the SEER-Medicare linked database.
This article outlines the availability of date of service information for the Limited Data Set (LDS) Medicare claims files.
Researchers may now request Research Identifiable File (RIF) Medicare data on a quarterly basis, in addition to the annual files.Data available on a quarterly basis includes FFS claims (Inpatient, Outpatient, Home Health Agency, Hospice, Skilled Nursing Facility, Carrier, and Durable Medical Equipment) and the Master Beneficiary Summary File: Base A/B segment.
This article provides a link and overview of the document on finder and crosswalk files written by the CMS data distributor, HealthAPT.
CMS began offering quarterly claims and enrollment data with Quarter 3, 2015. This article describes the quarterly data file creation, availability, and pricing.
This article is designed to provide a brief overview of the differences between the Medicare Current Beneficiary Survey (MCBS) Public Use File (PUF) and MCBS Limited Data Set (LDS) files so researchers can decide which file is appropriate for their study needs.
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, and research identifiable files.
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.