Reminder: DUA and VRDC access needs to be extended or renewed annually. Read more.
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…
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 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.
Claims for ambulance services are found in both the Carrier and the Outpatient claims data. This article describes how to identify ambulance services.
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.
With the exception of PY 2014, CMS research files do not include beneficiary risk adjustment scores. However, CMS does provide the programming code and instructions to calculate the three risk adjustments that CMS uses as the basis for managed care payment.
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.
Beginning in 2008, some hospital provider numbers appearing in the claims contain a “V” in the fifth position of the six-digit Medicare Provider Number. Usually, the fifth position is a number, not a character. These hospital provider numbers appear in the MedPAR, Inpatient and Outpatient files for both RIF and LDS versions. ResDAC recommends that researchers remove these claims.