Changes in Medication Use After Medicare Part D Annual Out-of-Pocket Spending Caps

Area of Science:

• Health Economics
• Pharmaceutical Policy
• Medicare Part D

Background:

• The Inflation Reduction Act (IRA) introduced annual out-of-pocket spending caps for Medicare Part D beneficiaries.
• These caps aimed to reduce financial burdens but their impact on medication access remained unclear.

Purpose of the Study:

• To evaluate the effect of the IRA's out-of-pocket spending caps on prescription medication fills within the Medicare population.
• To assess changes in medication access following the implementation of cost-saving policies.

Main Methods:

• Utilized an all-payer pharmacy database (Symphony Health Metys) from 2022 to 2025.
• Employed an event study and difference-in-differences framework to compare medication fills before and after the caps.
• Stratified medications by cost (low, medium, high, very high) to analyze differential impacts.

Main Results:

• Overall medication use in Medicare increased compared to commercial insurance post-implementation, with greater increases for higher-cost drugs.
• Very-high-cost medication use saw a significant increase of 22.7% (P=.01).
• Event-study analyses indicated increasing medication use over time, particularly for high-cost and very-high-cost medications.

Conclusions:

• The implementation of Medicare's out-of-pocket cost caps led to increased medication utilization.
• The findings suggest a substantial improvement in patient access to high-cost medications for Medicare beneficiaries.
• This policy demonstrates a positive impact on medication adherence and access for costly treatments.