Identifying Dual Eligible Medicare Beneficiaries in the Medicare Beneficiary Enrollment Files

Purpose

For data years 2006 and forward, dually eligible Medicare beneficiaries are identified in the Medicare Master Beneficiary Summary File, Base segment. Initially available only as a RIF, this file was released as an LDS file in 2016. The monthly variable “Medicare-Medicaid Dual Eligibility” identifies dual status.

Dual eligibles are also identified in the Medicaid Analytic Extract (MAX) Personal Summary (PS) file.

Current Version Date:
10/25/2018
Save as PDF (print)

Dual eligible enrollees are Medicare enrollees that are receiving some form of assistance from their states’ Medicaid program. Dual beneficiaries may receive all or some of the following:

  • Medicare Part B premium assistance
  • Medicare cost sharing payment assistance
  • Eligibility for full Medicaid services

Detailed descriptions of the various, specific types of dual eligibility are found on the CMS web site. The MBSF variable “Medicare-Medicaid Dual Eligibility Status” occurs monthly. The values identify:

  • Qualified Medicare Beneficiaries (QMBs)
    • Medicare Part B Premium and cost-sharing assistance
    • With or without Medicaid benefits
  • Specified Low-Income Medicare Beneficiaries (SLMBs)
    • Medicare Part B Premium Assistance
    • With or without Medicaid benefits
  • Qualified Disabled and Working Individuals (QDWIs)
    • Medicaid only pays the Medicare Part A premium
    • Beneficiaries spend down assets to be eligible
  • Qualifying Individuals (Qis)
    • Medicaid paid Part B Premiums, effective 1/1/1998 to 12/31/2002
    • Beneficiaries spend down assets to be eligible
  • Medicaid Only Dual Eligibles, entitled to full Medicaid benefits but receive not cost-sharing or premium assistance

Prior to the development of the MBSF variable with the implementation of the Part D program, there was no reliable way to identify all dually eligible from Medicare enrollment files.

Statistics on the Dual Eligible Population are available from the Kaiser Family Foundation.

Save as PDF (print)

Article Information

Author:
Gerri Barosso, RD, MPH, MS
Acknowledgements:
ResDAC would also like to acknowledge Sarah Garcia for assistance with this article.
Level:
Intermediate
Topic:
Analytic Guidance
Program:
Medicare, Medicaid
Category:
Beneficiary Enrollment and Summary
Disclaimer:
The process and materials mentioned as part of this KnowledgeBase article are current, as of the publication date on the article, to the best of our knowledge. The examples provided are correct in the aggregate but may not apply to every subgroup or circumstance that a researcher may wish to study. It is up to the researcher to conduct analysis and confirm that the patterns described in this KnowledgeBase article apply to his/her particular study. If your research findings appear to contradict the advice provided, please contact ResDAC at resdac@umn.edu.