If you have seen a headline about “the drug that costs Medicare billions,” it almost certainly came from the CMS Medicare Part D Spending by Drug dataset. Here is what it actually contains and how to read it.
What the dataset is
CMS publishes one row per drug (plus per-manufacturer breakdowns) covering the Medicare Part D outpatient prescription-drug program. The latest annual file covers data years 2019–2023, with 2023 the most recent year. It is free and in the public domain. We snapshot it and build a page for the highest-spend drugs; see our methodology.
What the key fields mean
| Field | What it means |
|---|---|
| Total spending | Gross drug cost: Medicare, plan and beneficiary payments combined, across all Part D claims for the drug that year |
| Spending per dosage unit | Total spending divided by total dosage units (pills, mL, etc.), volume-weighted |
| Spending per claim | Average gross cost of one filled prescription |
| Spending per beneficiary | Total spending divided by the number of unique people who used the drug |
| Claims / beneficiaries | How many prescriptions were filled, and how many distinct people used it |
| Change & CAGR | Year-over-year and multi-year change in spending per dosage unit |
What it does not tell you
- It is not the price you pay. Total spending is gross cost across the whole program. Your copay depends on your plan, deductible and coverage phase.
- It is not the net price. Manufacturer rebates are confidential and are not netted out, so “total spending” overstates what the program ultimately retains in cost.
- It is not a list price. It is an aggregate, not a per-unit sticker price.
How to use it
The data is great for spotting trends: which drugs drive program spending, which prices are rising fastest, and which medicines are most widely dispensed. Start with the biggest-spend ranking or browse the A–Z drug index.
This page is general information, not medical or pricing advice. Source: CMS Medicare Part D Spending by Drug, data year 2023, U.S. public domain.