Master Beneficiary Summary File (MBSF): Chronic Conditions Segment

The Chronic Conditions segment of the Master Beneficiary Summary File (MBSF) flags each Medicare beneficiary for the presence of one of 27 specific chronic conditions.

What does this file include? (variable highlights)

  • Three flags for each chronic condition:
    • First occurrence date
    • Mid year indicator
    • End of year indicator

Special considerations

  • The algorithms used to assign the flags are available from the CCW website.
  • Algorithms requiring a multiple-year look back period are completed without requiring the researcher to order multiple years of data.
  • Algorithms search data from Medicare Fee-For-Service (FFS) claims.
  • This file is a segment that can be requested in addition to the Master Beneficiary Summary File (MBSF) base file.

Availability of this file


CY 1999 - 2019

Date Requests Can Be Accepted for Upcoming Releases:

CY 2020 available 11/2021

See what is in this file