The Master Beneficiary Summary File includes several segments.
Base (A/B/C/D) segment: This segment includes beneficiary enrollment information, such as the beneficiary unique identifier, state and county codes, zip code, date of birth, date of death, sex, race, age, monthly entitlement and enrollment information (A/B/C/D) and plan information for Medicare Advantage (Part C) and the Prescription Drug Program (Part D). Part C and Part D enrollment information is available beginning with the 2006 file year.
Chronic Conditions segment: This segment includes 27 chronic condition data warehouse flags called CCW Flags. This includes 6 new chronic conditions in addition to the 21 chronic conditions previously defined. For more information about the CCW Flags, please see the CCW User Guide.
Other Chronic or Potentially Disabling Conditions segment: The Other Chronic or Potentially Disabling Conditions segment of the MBSF contains 9 mental health and tobacco use conditions, 15 developmental disorder and disability-related conditions, and 9 other chronic physical and behavioral health conditions which were developed by CMS specifically to enhance research of the Medicare-Medicaid dually enrolled population.
Cost & Use segment: This segment includes summarized information about the service utilization and Medicare payment amounts by file type.
National Death Index (NDI) segment: This segment includes the National Death Index cause of death information. This is available for all Medicare beneficiaries from 1999-2016.
Base (A/B/C/D) Segment
The Part D variables in the Base segment are available for years 2006 and forward only.
Chronic Conditions Segment
Other Chronic or Potentially Disabling Conditions Segment
Cost and Use Segment
The mid-year Cost and Use segment, which is available in the Fall, will not include Part D claims information.
National Death Index Segment