The Medicare Part D Formulary fileset is a suite of five files: Formulary, Excluded Drug, Over-the-Counter Drug, Indication-based Formulary, and Part D Senior Savings (PDSS) Model. This fileset contains information on the plan’s formulary, which is the list of prescription medications covered by the Part D plan.
Starting with the 2026 service year, CMS is releasing the Part D Formulary fileset quarterly. The new quarterly Part D data products will be produced after a three-month maturity run-out for a calendar quarter, following the same cadence as the quarterly Master Beneficiary Summary File and Original Medicare claims datasets. For example:
- Q1 2026 (January – March 2026) PDE was produced in July 2026
- Q2 2026 (April – June 2026) PDE was produced in October 2026
What does this file include? (variable highlights)
- CCW Formulary Drug Identifier
- Tier ID
- Step Therapy Indicator
- Quantity Limit
- Prior authorization
- Linkage variable to the PDE file record: Formulary Identifier (in each Formulary file)
Why do researchers request this file?
- To examine differences in utilization based on formulary inclusion or restrictions
- To examine plan differences in formularies
Special considerations
- Part D Characteristics files for service years prior to 2026 are available as annual files only.
- The Tier ID available in this file may be linked to the Plan Characteristics File.
- When the Formulary characteristics data is requested and approved, all files are delivered.
