IRA Reforms To Medicare Part D Reinsurance Were Associated With Plan Exits And Higher Premiums, 2024-25

Area of Science:

• Health Economics
• Public Policy
• Pharmaceutical Policy

Background:

• The Inflation Reduction Act (IRA) of 2022 significantly modified Medicare Part D prescription drug financing.
• Federal reinsurance contributions for beneficiaries exceeding a certain spending threshold decreased from 80% to 20% starting in 2025.

Purpose of the Study:

• To analyze the impact of IRA reinsurance reforms on Medicare Part D plan exit, premium adjustments, and benefit design.
• To investigate the relationship between pre-IRA reinsurance levels and plan behavior under the new financing structure.

Main Methods:

• Examined the effect of reinsurance reforms on free-standing Medicare Part D plans.
• Analyzed plan exit data, premium changes, and benefit design features.
• Assessed participation in the 2025 Medicare Part D Premium Stabilization Demonstration based on pre-IRA reinsurance.

Main Results:

• Pre-IRA reinsurance payments emerged as a significant predictor of Medicare Part D plan exit post-reform.
• Plans with higher pre-IRA reinsurance were more likely to receive demonstration subsidies but also substantially increased premiums in 2024-2025.
• No significant association was found between pre-IRA reinsurance and changes in benefit design, such as coverage or out-of-pocket spending.

Conclusions:

• Reinsurance reforms under the IRA have played a key role in recent Medicare Part D market volatility.
• These reforms influenced plan stability and pricing strategies, leading to increased premiums despite stabilization efforts.