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 purpose of this article is to provide an overview of the Centers for Medicare & Medicaid Services' (CMS') Price (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.
Availability of provider variables Provider variable completeness Provider variable definitions
This article presents the data options available to researchers studying the End-Stage Renal Disease (ESRD) population. 
Medicare-paid observation stays may be found in the Medicare Outpatient, Inpatient, or MedPAR files. This article describes how to identify observation stays that appear in each as defined by CMS billing guidance.
A number of CMS Limited Data Set (LDS) files are released first as a Proposed Rule file and then as a Final Rule file. This article provides a brief description of the differences between those 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 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.
The purpose of this knowledge base article is to 1) present an overview of International Classification of Disease (ICD) codes and versions available, 2) describe where researchers can find these codes in the Medicare claims, and 3) understand how ICD codes appear in the data.
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.
This article provides instructions on how to open the Medicare Physician/Supplier Procedure Summary Master (PSPS) file in Microsoft Access or SAS.
The purpose of this article is to define a Long-Term Care Hospital (LTCH) and to identify the files that contain claims submitted by a LTCH.
Under changes to the Part 2 regulations on January 17, 2017, CMS is now permitted to include substance use disorder claims data in the Research Identifiable Files (RIFs).  Research Identifiable Files shipped or extracted in the VRDC after 05/22/2017 are no longer subject to the redaction.