OBJECTIVES: This study will explore the impact of the 2024 Inflation Reduction Act (IRA) on Medicare Part D plans, focusing on small, single-drug manufacturers. The IRA has removed coinsurance and copayments for Medicare patients in the catastrophic phase, with costs shared by Part D plans and drug manufacturers. It also limited Medicare Part D premium increases to 6%. Amidst escalating cost pressures, approximately 180 small manufacturers, will see a phase-in of their cost liability of 20%. This liability, additional costs, is set to transition to Part D plans. Our objective is to assess the future impact of this liability shift on the formulary access provided by Part D plans.

METHODS: The study will engage 15-20 managed care decision-makers in a quantitative electronic survey, followed by five qualitative in-depth interviews. The focus will be on the impact of the 2024 Inflation Reduction Act on Medicare Part D plans, particularly the effects of the catastrophic discount liability shift on formulary access.

RESULTS: The results will be an aggregated view of the effects of the catastrophic discount liability shift on formulary access. The results could reveal how the Act’s changes, including the removal of the patient’s coinsurance and copayments, and the limitation on premium increases, affect these manufacturers and the formulary access provided by Part D plans.

CONCLUSIONS: Despite needs to reduce patient burden, the IRA may inadvertently burden payers, escalating costs and limiting options for US Medicare patients. This could potentially impact commercially insured patients as well.