Part D Denominator

The Part D Denominator File contains demographic and enrollment information about each Medicare beneficiary enrolled in the Part D program during a calendar year. This file is not available after March of 2010. This file was incorporated into the Beneficiary Summary File.

This file includes:

  • beneficiary unique identifier,
  • state and county codes, zipcode,
  • date of birth,
  • date of death,
  • sex,
  • race/ethnicity, 
  • monthly Part D entitlement indicators

The Part D Denominator covered CY 2006-2009. Distribution of this file began in mid-2009 and was discontinued in March 2010. This file is no longer available for request. The information in this file is now found in the Master Beneficiary Summary file, Base (a/b/d) segment.

Data File Classification