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Biosimilar Trends in Medicare Part D

Biologic drugs—generally large, complex molecules produced in a living system—are among the most expensive drugs on the U.S. market. Biosimilar drugs are highly similar and have no clinically meaningful difference from their reference biologics; they also tend to be less expensive than their reference biologics. Medicare Part D and beneficiaries have the potential to spend less on prescription drugs with the increased use of biosimilars rather than their reference biologics, but use of biosimilars remains low. Limited coverage of biosimilars by Part D plans and formulary tier placement may discourage the use of less expensive biosimilars. Our study will describe utilization and cost trends of biosimilars and reference biologics covered by Part D over time. In addition, we will determine how much Medicare and beneficiaries paid for biosimilars and reference biologics covered by Part D in 2019, and then compare those costs to determine how much Part D and beneficiaries would have spent with increased use of biosimilars.

Announced or Revised Agency Title Component Report Number(s) Expected Issue Date (FY)
Completed Centers for Medicare and Medicaid Services Biosimilar Trends in Medicare Part D Office of Evaluation and Inspections OEI-05-20-00480 2022