Medicare

Medicare is a health insurance program, administered by the United States government, for people who are aged 65 and over; to those who are under 65 and are permanently physically disabled or who have a congenital physical disability; or to those who meet other special criteria like the End Stage Renal Disease program (ESRD).

Medicare-Medicaid Linked Enrollee Analytic Data Source (MMLEADS) 3.0

The Medicare-Medicaid Linked Enrollee Analytic Data Source (MMLEADS) 3.0 suite of files combines Medicare and Medicaid enrollment and claims data into two annual beneficiary-level files. The files include beneficiaries who are Medicare-only, Medicare-Medicaid dually enrolled and Medicaid-only blind and disabled.

What is different about MMLEADS 3.0?

MMLEADS now consists of two files—a beneficiary summary file and single cost (i.e., payments) and use (i.e., claim counts) file that combines Medicare and Medicaid information. CCW Chronic Condition and other condition flags are no longer provided.

Source data

Medicare: FFS, PDE and MA

Medicaid: T-MSIS data

What does this file include? (variable highlights)

  • Eligibility, enrollment variables
  • Aggregated claim counts and payment amounts
    • Medicare: FFS, PDE includes FFS and MA
    • Medicaid: FFS, managed care encounter where available
  • Both files are released for approved MMLEADS data requests
    • Beneficiary file
    • Medicare and Medicaid cost and use file

Special considerations

External resource of detailed information on MMLEADS files and structure: CCW MMLEADS User Guide

Comprehensive ESRD Care (CEC) Model - Provider

CMS has created an analytical file that contains information about providers who are participating in the Comprehensive ESRD Care (CEC) Model. A related file, the CEC Beneficiary RIF, contains identifying information about the beneficiaries assigned to a provider who is participating in the CEC Model. 

The CEC Provider Performance Year RIF files contain PY finder files for the providers participating in the ESRD Seamless Care Organization (ESCO). 

What does this file include? (variable highlights)

  • ESCO Name 
  • Period of Performance 
  • Tax Identification Number of the practice/facility associated with the Individual NPI 
  • Parent Participant NPI Number 
  • Organization Name 
  • Provider Type description 
  • CMS Certification Number (CCN)

Special considerations 

  • This file can be linked to any other CMS file that include the TIN, CCN, or NPI.
  • PY1 is for a 15 month period beginning in October, all other PYs are for a calendar year beginning in January.
  • All technical questions related to the CEC program should be directed to ESRD-CMMI@cms.hhs.gov.

Comprehensive ESRD Care (CEC) Model - Beneficiary

CMS has created an analytical file that contains enrollment data for beneficiaries in the Comprehensive ESRD Care (CEC) Model. A related file, the CEC Provider RIF, contains identifying information about the providers participating in the CEC Model. 

The CEC Beneficiary Performance Year RIF files contain PY finder files for the beneficiary population attributed to an ESRD Seamless Care Organization (ESCO).

What does this file include (variable highlights) 

  • Beneficiary ID (allows linkage to other files)
  • ESCO Name 
  • Monthly assignment status information 
  • Date of birth 
  • Date of death 

Special Considerations 

  • This file can be linked to any other CMS file that includes the Bene ID. 
  • PY1 is for a 15 month period beginning in October, all other PYs are for a calendar year beginning in January.
  • All technical questions related to the CEC program should be directed to ESRD-CMMI@cms.hhs.gov.

Home Health Outcome and Assessment Information Set (OASIS)

The Home Health Outcome and Assessment Information Set (OASIS) contains data items developed to measure patient outcomes and for improve home health care. The OASIS assessments are required of all home health agencies certified to accept Medicare and Medicaid payments.

What does this file include? (variable highlights)

  • HIPPS code
  • Socio-demographic variables
  • Information on patient home environment and informal caregivers
  • Health status, including diagnosis codes
  • Functional status
  • Psychosocial status
  • Health service utilization
    • Emergent care
    • Hospital admission

Special considerations

  • The Medicare Prescription Drug Improvement and Modernization Act of 2003 (MMA) suspended required completion for non-Medicare and non-Medicaid patients.

Long Term Care Minimum Data Set (MDS) 2.0

The Long Term Care Minimum Data Set (MDS) is a health status screening and assessment tool used for all residents of long term care nursing facilities certified to participate in Medicare or Medicaid, regardless of payer. The assessment is also required for Medicare payment of skilled nursing facility stays. Assessment data for Skilled Nursing Swing Beds 2.0 is included in a separate file. Version 2.0 was replaced by MDS version 3.0 on October 1, 2010.

What does this file include? (variable highlights)

  • Resource Utilization Group (RUG) code
  • Clinical status measures
  • Physical functioning assessment
  • Psychological status measures
  • Psycho-social functioning measure
  • End-of-life care decisions

Plan Characteristics File

The Plan Characteristics file contains Medicare Advantage plan and Prescription Drug Plan information separated into six subfiles.

The subfiles are:

  • Plan Base
  • Premium
  • Tier
  • Service Area
  • Plan Crosswalk
  • SNP Contract

What does this file include? (variable highlights)

  • Initial and gap coverage limits
  • Plan premium amount
  • Plan service area description
  • Crosswalk of current plan ID to previous years
  • Demonstration type
  • Special needs plan type
  • Linkage variables to the PDE and to each of the Plan Characteristic File sub-files:
    • Plan Contract ID, Plan Benefit Package ID (use in combination to link to specific plan)

Why do researchers request this file?

  • Studies that compare medication usage and clinical outcomes by plan benefits

Special considerations

  • Plan identifiers are encrypted in the data prior to the CY2015 file, so researchers must use this file to find out more information about the plan. Beginning with the CY2015 file, plan contract ID numbers are not encrypted
  • This file consists of six sub-files.
  • When the Plan characteristics file is requested and approved, all subfiles are delivered.

Long Term Care Minimum Data Set (MDS) 3.0

The Long Term Care Minimum Data Set (MDS) is a health status screening and assessment tool used for all residents of long term care nursing facilities certified to participate in Medicare or Medicaid, regardless of payer. The assessment is also required for Medicare payment of skilled nursing facility stays. Assessment data for Skilled Nursing Swing Beds 3.0 is included in a separate file, MDS version 3.0 was implemented on October 1, 2010, replacing version 2.0.

What does this file include? (variable highlights)

  • Resource Utilization Group (RUG) code
  • Clinical status measures
  • Physical functioning assessment
  • Psychological status measures
  • Psycho-social functioning measure
  • End-of-life care decisions

Long Term Care Minimum Data Set (MDS) - Swing-Bed 3.0

The Long Term Care Minimum Data Set (MDS)-Swing Bed is a health status screening and assessment tool. It is required for Medicare payment of hospital-based skilled nursing care. Swing-bed providers are hospitals that can use their beds, as needed, to provide either acute or post-acute skilled nursing care.  The swing-bed assessment includes a subset of the skilled nursing facility (SNF) assessment items. The MDS 3.0 was implemented in October, 2010, replacing version 2.0.

What does this file include? (variable highlights)

  • Resource Utilization Group (RUG) code
  • Clinical status measures
  • Physical functioning assessment
  • Psychological status measures
  • Psycho-social functioning measure

Medicare-Medicaid Linked Enrollee Analytic Data Source (MMLEADS) 2.0

The Medicare-Medicaid Linked Enrollee Analytic Data Source (MMLEADS) 2.0 suite of files combines Medicare and Medicaid enrollment and claims data into four annual beneficiary-level files. The files include beneficiaries who are Medicare-only, Medicare-Medicaid dually enrolled and Medicaid-only blind and disabled.

Source data

  • Medicare: FFS, PDE and MA
  • Medicaid: MAX data

What does this file include? (variable highlights)

  • Eligibility, enrollment variables
  • Aggregated cost and use
    • Medicare: FFS, PDE includes FFS and MA
    • Medicaid: FFS, managed care encounter where available
  • Prescription Drug service utilization reported for classes of drugs
  • Chronic Condition flags - 27 CCW Chronic Conditions plus an additional 25 other condition flags
  • All four files are released for approved MMLEADS data requests
    • Beneficiary file
    • Medicare Services file
    • Medicaid Services file
    • Conditions file

Special considerations