Medicare Part D plan designs hold steady in initial wake of Inflation Reduction Act implementation, researchers find

A new study has found that Medicare Part D plan designs have remained largely unchanged since the implementation of the Inflation Reduction Act in 2025, according to health services policy and management assistant professor David Anderson. The researchers, whose findings were published in Health Affairs, discovered that insurers primarily responded to the act by lowering premiums and raising deductibles.

The Inflation Reduction Act introduced two key changes to Medicare Part D: a $2,000 cap on out-of-pocket drug costs and a shift in responsibility for costs exceeding this limit from 20% to 60%. As a result, premiums decreased, making monthly costs more affordable, while deductibles increased more than expected, leading to higher out-of-pocket expenses before coverage begins.

Drug coverage became slightly more restrictive, and plan availability declined as some insurers chose to exit the market. While changes to restrictions and pharmacy networks were minimal, the researchers noted that the overall number of available plans shrank. Anderson emphasized that insurers appear to be rebalancing their plans by shifting beneficiary costs from monthly payments to upfront payments.

With the policy environment continuing to evolve, he stressed the importance of monitoring the Medicare Part D market to ensure beneficiaries continue to receive relief from high prescription drug costs.