Updated April 2026 · CMS Medicare Part D
Drug Price Trend Reports
Data-driven reports on which prescription drugs moved most year over year, drawn directly from successive releases of the CMS Medicare Part D Drug Spending Dashboard. The reports surface generic-launch effects, biosimilar competition, manufacturer hikes, and the early impact of Medicare negotiation under the Inflation Reduction Act.
What Drives U.S. Drug Price Trends
Year-over-year drug price moves cluster around three forces. First, market exclusivity transitions — when the first A-rated generic launches, prices typically drop 30–60% within a year, and the FDA Orange Book signals when a brand is approaching that cliff. Second, biosimilar adoption — slower than generics, but with multi-year impact as PBMs reset formularies. Third, manufacturer-driven increases on legacy or orphan drugs that lack competitive pressure, which show up as outsized spikes in the CMS spending data.
Trend reports focus on the extremes. The biggest year-over-year drops are typically post-launch generics and the first wave of biosimilars; the biggest increases are typically older injectables, branded combination products, and small-population drugs without competition. The Inflation Reduction Act negotiation list adds a fourth force — direct CMS-negotiated price cuts that took effect January 2026 — and reports here track the spending impact of that program release-by-release.
Top 5 Biggest Year-over-Year Increases
Browse All Trend Reports
Drugs With the Biggest Price Increases
Year-over-year Medicare cost changes
Drugs with the largest negative price moves — generic launches, biosimilar competition, and expired exclusivity windows that show up directly in the CMS spending data.
Most Expensive Medicare Drugs
The drugs costing Medicare the most each year
Snapshot reports capture the current state of a slice of the market — the most expensive drugs, the biggest CMS spend, the largest year-over-year increases.
Drugs Going Generic Soon
Expensive brand-name drugs with upcoming patent expirations
Snapshot reports capture the current state of a slice of the market — the most expensive drugs, the biggest CMS spend, the largest year-over-year increases.
How Trends Are Calculated
For each drug in the CMS Medicare Part D Drug Spending Dashboard, we compute the year-over-year change in average cost per claim using the most recent two annual releases. We then bucket drugs into "biggest increases" (largest positive moves), "biggest decreases" (largest negative moves), and "aggregate movers" (class- or manufacturer-level patterns that emerge when individual drug moves are summed). Patent and exclusivity status from the FDA Orange Book is joined to flag generic and biosimilar launches that explain the movement. The full DrugPrice methodology documents the calculation, edge cases, and update cadence.
Frequently Asked Questions
What is a drug price trend?
A drug price trend is the year-over-year change in the average cost per claim for a specific drug, drawn from successive releases of the CMS Medicare Part D Drug Spending Dashboard. Positive percentages mean prices rose; negative percentages mean they fell, usually because a generic launched, a biosimilar entered the market, or Medicare negotiated a new price under the Inflation Reduction Act. Last refreshed April 2026.
Why do some drugs spike in price year over year?
A handful of forces drive most large drug price increases: shortages that push more demand to remaining suppliers, manufacturer price hikes on legacy small-population drugs (especially injectables and orphan drugs), and shifts in patient mix toward higher-cost packaging or strengths. The "biggest increases" report identifies which force dominates each spike using FDA shortage data and Orange Book status.
Why do some drugs fall sharply in price?
The dominant cause of price declines is generic or biosimilar competition. When the first A-rated generic launches, prices often drop 30–60% within a year and 80%+ within five years. Biosimilars (like the Humira and Stelara entrants of the past two years) move more slowly because of formulary inertia, but they show up clearly in CMS data over a 24–36 month window.
Are these trends seasonal?
No — CMS publishes Part D spending data on an annual cycle, so trend reports here reflect calendar-year movement rather than seasonal swings. Within-year price changes (a manufacturer mid-year hike, a CMS negotiated price taking effect) typically do not show up until the following annual release.
How are these reports compiled?
Each trend report is built by taking the most recent two years of CMS Part D spending data, computing year-over-year change in average cost per claim per drug, joining FDA Orange Book status (generic, brand, exclusivity), and applying the relevant filter (biggest increases, biggest decreases, biggest aggregate moves by class). The full DrugPrice methodology page documents the data joins, the cleaning steps, and the refresh cadence.
Sources: CMS Medicare Part D Drug Spending Dashboard, FDA Orange Book, CMS Inflation Reduction Act negotiation announcements. All data is U.S. government public domain. Cite as: "DrugPrice, April 2026 trend reading. Data: CMS Part D & FDA."
Last updated 2026-04-06 · 3 trend reports published.