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.
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…
This article describes three variable groups that can be used to identify managed care enrollment for Medicaid beneficiaries. Codes for the variables are also given that identify beneficiaries who received their comprehensive medical care under the Fee-For-Service (FFS) payment system.
This article has three goals: (1) to describe missing patterns on pain variables; (2) to describe the difference between real missing and skip patterns; (3) to describe which assessments should be used for calculating pain measures. This information is most relevant for researchers who work on either creating their own pain measures or constructing CMS quality measures. The new MDS 3.0 requires nursing home staff to interview residents regarding health conditions, such as pain, mood and cognitive function through…
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 summarizes two methods available to link mothers and their infants using the MAX data. Frequently researchers using the CMS Medicaid Analytic Extract (MAX) data are looking for ways to link mothers with their infants. Given the available identifiers in MAX data, there are two options.
Provide the steps to identify the drug name from the RxNorm database for the NDCs in the BSA PDE PUF. 
CMS updated several Medicare cost report forms. As a result, during the year of the transition and up to one year after, the facility will have two separate data downloads, one that includes all the data collected under the old form and another one under the new form. 
Values that are "missing" in the Minimum Data Set (MDS) nursing home assessment can be represented by several different symbols. While all of these symbols represent that a value is "missing," the specific symbol indicates the specific reason why the value is missing.
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.
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.
This article explains possible discrepancies when using the outpatient file to calculate payment amounts at the claim level and revenue center level.
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.