Changes in Medicare Part D Plan Designs After the Inflation Reduction Act

After the Inflation Reduction Act (IRA), Medicare Part D plans increased deductibles and relied more heavily on coinsurance for brand-name drugs. For the most common medications, average monthly out-of-pocket costs in Medicare Advantage plans ranged from $46 to $55 between 2019 and 2024 and then increased to $73 in 2025. In standalone plans, mean monthly costs increased from $62 to $108 from 2019 to 2025. While the IRA capped annual out-of-pocket spending at $2,000, these plan design changes may result in higher costs for beneficiaries who do not reach the cap, suggesting a need for further policy action.