Skip to main content
DrugPrice

Inflation Rebate Penalty

An IRA provision requiring drug manufacturers to pay Medicare rebates when a drug's price increases exceed general inflation (CPI-U) on a year-over-year basis.

How It Works

The inflation rebate penalty under IRA Section 11101 (Part B) and Section 11102 (Part D) requires manufacturers to pay Medicare a rebate equal to the difference between the drug's actual price and an inflation-adjusted benchmark price, multiplied by Medicare-covered units. The Part B provision took effect January 1, 2023, and CMS issued the first Part B inflation rebate invoices in late 2023 for Q1 2023 utilization. The Part D provision began accruing October 1, 2022 (for the rebate year ending September 30, 2023), with invoices expected to start hitting manufacturers in 2025. Drugs exceeding CPI-U growth face rebate liability on Medicare-covered units: CMS identified 48 Part B drugs subject to inflation rebates for Q4 2024, including Keytruda, Padcev, Opdivo, and Eylea. The benchmark price is set at the 2021 payment amount and inflated forward by CPI-U; any drug whose actual AMP or ASP exceeds the benchmark owes the difference. Rebates can substantially exceed the original price increase on a per-unit basis because they are multiplied by total Medicare-covered units. Importantly, the inflation rebate is applied to coinsurance calculations, reducing beneficiary cost-sharing when a drug has triggered rebates, so patients share directly in the savings. The inflation rebate has visibly altered manufacturer list-price behavior: the January 2024 Part D list-price hike wave saw smaller and fewer increases than historical norms, with median increases well below CPI-U.

Related Terms

  • Inflation Reduction Act (IRA), A 2022 federal law that, for the first time, allows Medicare to negotiate prices directly with drug manufacturers for select high-cost medications and creates new inflation rebate and Part D redesign provisions.
  • Wholesale Acquisition Cost (WAC), The manufacturer's list price for a drug sold to wholesalers, often called the "sticker price" before any rebates or discounts.
  • Drug Price Increase, When a manufacturer raises the list price (WAC) of an existing drug, historically a common practice that drove much of the growth in U.S. drug spending.
  • Medicare Part D, The prescription drug benefit within Medicare, covering outpatient medications for 50+ million Americans aged 65+ and those with disabilities.

Explore Drug Data

Most Expensive DrugsGeneric Drug WatchSearch All Drugs

About This Definition

This definition is part of the DrugPrice Drug Pricing Glossary, 49 terms explaining how prescription drug pricing works in the United States. All definitions are written in plain language for patients, caregivers, journalists, and healthcare professionals.

this entity is one of the U.S. Medicare prescription-drug pricing concepts that recurs across this site. The definition above is the technical answer; the paragraphs below add the practical context for how the concept connects to the CMS Medicare Part D Drug Spending data data behind every per-entity page on the site.

In the CMS Medicare Part D Drug Spending data data, this concept shapes one or more of the fields that drive the per-entity grades and rankings on this site. The methodology page describes which fields feed into which output; this glossary entry documents the underlying term.

Source: CMS Medicare Part D Spending, 2026.