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 may request Research Identifiable File (RIF) Medicare data on a quarterly basis, in addition to the annual files. Data available on a quarterly basis includes Medicare Research Identifiable 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.
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.
Hospitals may submit multiple claims for some hospitalizations. This article provides guidance for counting distinct inpatient hospitalizations and for sequencing claims for each distinct hospitalization found in the Inpatient Research Identifiable File (RIF) and Limited Data Set (LDS) files. This guidance is not applicable to the MedPAR because each record in that file is already a distinct hospitalization.
This article provides guidance on how to identify hospital emergency room claims from the Medicare files.
Provide the steps to identify the drug name from the RxNorm database for the NDCs in the BSA PDE PUF. 
Researchers working with the Research Identifiable (RIF) MedPAR or Inpatient and Skilled Nursing Facility (SNF) claims may find records that do not appear to correspond to the year of the file. This article explains these instances. 
This article describes the difference between two similiar variables in the carrier file -the Line NCH Payment Amount and Line Provider Payment Amount.
This article explains possible discrepancies when using the outpatient file to calculate payment amounts at the claim level and revenue center level.