​Beginning April 1, 2023, the coinsurance for select Part B rebatable drugs will be reduced if the drug's price has increased at a faster rate than inflation. This benefit falls under the Part B Rebatable Drug Coinsurance Adjustment provision of the Inflation Reduction Act.  

CMS will publish the adjusted beneficiary coinsurance for each Part B rebatable drug in the quarterly pricing files posted on the CMS website, which will note:

• “Inflation-adjusted coinsurance" in the Notes column if the coinsurance for a Part B drug or biological should be less than 20 percent of the Medicare Part B payment amount.
• Your Medicare portion of payment and the patient coinsurance percentage for each HCPCS code of a drug or biological, so you can charge patients correctly.

Starting April 1, 2023, when a Part B coinsurance lower than 20 percent applies for a rebatable drug for a calendar quarter:

• You must charge patients the correct amount of coinsurance.
• The Medicare portion of your payment will be increased for the difference between the Medicare Part B payment amount and patient coinsurance, minus any Part B deductible and sequestration.

For the time period of April 1 to June 30, 2023, CMS has published the list on its website, which contains  the 27 Part B rebatable drugs that have an adjusted coinsurance rate based on the inflation-adjusted payment amount.