Updated research request forms and data security approval requirement effective 4/24/23
Knowledgebase
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…
Popular
Articles
This article provides guidance on how to identify hospital emergency room claims from the Medicare files.
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…
To describe the CMS cell size suppression policy and provide examples of common scenarios and possible options.
Featured Article
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…
This article outlines the provider identification numbers that are available in the MAX files and options for linking to the Medicare Provider Number.
This article describes the structure of the Medicare cost reports and provides instructions for identifying specific data elements for specific facilities. While the examples and screenshots provided below are specific to the hospital cost reports, the discussion on file structure and logic used for identifying specific variables are applicable to any facility cost report.
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.
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.
The Internet Archive is a useful resource for finding historical copies of the Centers for Medicare and Medicaid Services (CMS) websites, reports or statistics that are no longer available.
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.
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.
The purpose of this article is to describe the difference between the two modules available for the MCBS between 1991-2013.
Researchers who are interested in studying Part D utilization within the Medicare Current Beneficiary Survey (MCBS) can do so by using the MCBS Cost and Use for years 2006 through 2013. This article provides an overview of where Part D utilization information located within the MCBS during these years, as well as the list of PDE variables included with the file.
This article describes the Federal Regulations that govern the release of CMS data for research.
CMS offers several claim-level files that contain outpatient claims; that is, facility claims submitted for care covered under Part B. Three versions of the LDS files are described:Outpatient file,Outpatient Prospective Payment System (OPPS) file, and OPPS Partial Hospitalization file.
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.