Skip to main content
DrugPrice

Our Methodology

DrugPrice makes prescription drug costs transparent by combining Medicare spending data with patent and generic availability information. We help patients understand what their drugs cost the healthcare system and when cheaper alternatives may become available.

Data Sources

  • CMS Medicare Part D Drug Spending Dashboard — Our primary source for drug cost data. Published by the Centers for Medicare & Medicaid Services at data.cms.gov, this dataset includes total spending, number of claims, average cost per claim, and year-over-year price changes for every drug covered by Medicare Part D.
  • FDA Orange Book — The official source for patent protection and therapeutic equivalence data. We use this to track active patents, exclusivity periods, and approved generic equivalents for brand-name drugs.
  • openFDA API — For supplemental drug label information including indications, dosage forms, and manufacturer details.

Price Data Explained

The prices shown on DrugPrice are average cost per claim from Medicare Part D, which represents what Medicare (and beneficiaries) actually pay per prescription fill. This is different from:

  • List price (WAC) — The manufacturer's published price before rebates, which is often much higher than what anyone actually pays.
  • Out-of-pocket cost — What a patient pays depends on their specific insurance plan, deductible status, and copay tier.

We use Medicare Part D data because it represents the largest single-payer prescription drug program in the US and provides standardized, auditable cost data across all covered drugs.

Generic Availability Tracking

For each brand-name drug, we track patent expiration dates and FDA-approved generics using the Orange Book. Our "Generic Watch" page highlights drugs with expiring patents where generic competition may soon reduce costs.

Data Collection Process

We download the Medicare Part D Spending Dashboard dataset from data.cms.gov, join it with Orange Book patent and exclusivity data, and enrich with drug label metadata from the openFDA API. Year-over-year price changes are calculated from the CMS data directly.

Update Frequency

CMS publishes updated Medicare Part D spending data annually, typically in the spring for the prior calendar year. FDA Orange Book data is updated monthly. We refresh our dataset when new CMS spending data becomes available.

Known Limitations

  • Medicare Part D data only covers Medicare beneficiaries (primarily age 65+). Prices for commercially insured or uninsured patients may differ significantly.
  • Rebates negotiated between manufacturers and pharmacy benefit managers are confidential and not reflected in the average cost per claim.
  • Specialty drugs administered in physician offices (Part B) are not included in Part D data.
  • Patent expiration does not guarantee immediate generic availability — FDA approval and manufacturing timelines create additional delays.

How to Cite This Data

If you use data from DrugPrice, please cite:

DrugPrice. "[Drug Name] Pricing Data." drugprice.org, 2026. Accessed [date].

Underlying data is sourced from CMS Medicare Part D Spending Dashboard and FDA Orange Book. All sources are in the public domain.