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…
Researchers and data users who are working with CMS files may need to map zip code information to CMS carriers and localities. This article describes where to find current and historical versions of the file.
This article provides instructions on how to open the Medicare Physician/Supplier Procedure Summary Master (PSPS) file in Microsoft Access or SAS.
The Centers for Medicare & Medicaid Services (CMS) seeks to ensure the protection of CMS data that are disclosed to external organizations for research purposes. To accomplish this, CMS has developed the Data Privacy Safeguard Program (DPSP). The DPSP reflects the Agency's 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.
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 requesting and using the data.
Part D Event (PDE) files for data years prior to 2010 may include the values of “XX” or “NA” for any of the four Utilization Management variables. This article describes when and why each value was used.
For data years 2006 and forward, dually eligible Medicare beneficiaries are identified in the Medicare Master Beneficiary Summary File, Base segment. Initially available only as a RIF, this file was released as an LDS file in 2016. The monthly variable “Medicare-Medicaid Dual Eligibility” identifies dual status. Dual eligibles are also identified in the Medicaid Analytic Extract (MAX) Personal Summary (PS) file.
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.
This article describes the Federal Regulations that govern the release of CMS data for research.
Cost report variables are split between two data files depending on the format of the variable. A master table lists all cost report variables and the format. The “Usage” column in the master table specifies the format of the variable, which determines the file location.
This article provides guidance on how to identify hospital emergency room claims from the Medicare files.
Claims for ambulance services are found in both the Carrier and the Outpatient claims data. This article describes how to identify ambulance services.
This article provides a link and overview of the document on finder and crosswalk files written by the CMS data distributor, HealthAPT.