Medicare Part D Coverage of Drugs Selected for the Drug Price Negotiation Program

Published in JAMA Health Forum, this study examined current Medicare beneficiary access to the drugs selected for the first round of the Inflation Reduction Act’s Medicare Drug Price Negotiation Program.


Julie Patterson, PharmD, PhD; Tyler Wagner, PharmD, PhD; John M. O’Brien, PharmD, MPH; and Jon D. Campbell, MS, PhD


JAMA Health Forum


This cross-sectional study describes and historically benchmarks Medicare Part D coverage in 2019 and 2023 for the first 10 drugs selected for negotiation under the Inflation Reduction Act’s (IRA) Medicare Drug Price Negotiation Program (DPNP).


Among the 10 drugs, average coverage was generally high and increased from 2019 to 2023. 

  • Across 3,345 plans examined, coverage in 2019 averaged 82%
  • Across 4,362 plans examined, coverage in 2023 averaged 91.3%


  • Beneficiary access to the first ten selected drugs was high in 2019 and 2023, with most available to beneficiaries without prior authorization or step therapy requirements.
  • Current CMS guidance requires Part D plans to include all dosage forms and strengths of selected Part D drugs on formularies, but offers less clear guidance on final utilization decisions by Plan D. Because of the lack of requirements, Plan D sponsors have freedom to apply utilization management tools like prior authorization and step therapy.
  • The IRA creates strong perverse incentives for Part D plans to maximize rebates by potentially using utilization management and adverse tiering for the drugs selected.
  • The increased utilization management requirements that are likely to emerge in response to Part D redesign could reduce patient access to treatments, counter to the intended effects of the DPNP.
  • The IRA’s formulary inclusion requirement may improve access to selected drugs previously excluded from the plan (like insulin), but access concerns beyond formulary inclusion remain — including the potential for copays for selected drugs to increase if their formulary placement changes.
JAMA Health Forum Study

Read the full study now.

JAMA Health Forum