EXPLORING THE POTENTIAL IMPACT OF THE INFLATION REDUCTION ACT’S PART D REDESIGN ON FORMULARY COVERAGE?IN COMPETITIVE CLASSES: 2024-2026
Author(s)
Hanke Zheng, MS, PhD1, Julie Patterson, PharmD, PhD2, Jon Campbell, PhD2;
1National Pharmaceutical Council, Research Manager, Washington, DC, USA, 2National Pharmaceutical Council, Washington, DC, USA
1National Pharmaceutical Council, Research Manager, Washington, DC, USA, 2National Pharmaceutical Council, Washington, DC, USA
OBJECTIVES: To examine changes in Medicare Part D formulary coverage of brand-only drugs in competitive classes from 2024 to 2026 and compare these with commercial plans.
METHODS: We selected competitive pharmacological classes in the US Pharmacopoeia with at least four commercially available brand-only drugs, excluding drugs administered by a healthcare provider, not covered by Part D, and/or primarily covered under Part B. Classes were excluded if subject to legislative coverage mandates/restrictions, had limited therapeutic relevance to older adults, or experienced launch of a first generic, biosimilar, or authorized generic in the study period. Using Clarivate’s Fingertip Formulary database, we compared beneficiary-weighted coverage for included drugs from 2024 to 2026 across Medicare Advantage Prescription Drug (MA-PD), stand-alone Part D (PDPs), and commercial plans. We calculated absolute changes in average coverage from 2024-2026 by plan type and conducted paired Wilcoxon signed-rank tests.
RESULTS: We identified 50 drugs across nine competitive classes spanning therapeutic areas (e.g., diabetes, multiple sclerosis). Average beneficiary-weighted coverage in 2026 was highest in commercial plans (72.8%), followed by MA-PD (53.5%) and PDP plans (40.2%). Coverage declines from 2025 to 2026 were numerically largest in PDPs and smallest in commercial plans. Average coverage in PDPs declined from 53.9% in 2024 to 46.9% in 2025 (p<0.01) and further declined to 40.2% in 2026 (p<0.01). MA-PD plans experienced a decrease in coverage from 2024 (61.5%) to 2025 (57.6%; p<0.05) and from 2025 to 2026 (53.5% in 2026; p<0.05). In contrast, coverage in commercial plans remained stable in 2025 (2024: 75.0%; 2025: 74.5%; p = 0.9) and decreased by 1.7% in 2026 (72.8%; p<0.01).
CONCLUSIONS: Our findings suggest that compared to commercial plans, Medicare Part D plans experienced larger reductions in coverage of brand-only drugs in competitive classes following the Inflation Reduction Act’s formulary redesign, with the greatest declines observed in standalone PDPs.
METHODS: We selected competitive pharmacological classes in the US Pharmacopoeia with at least four commercially available brand-only drugs, excluding drugs administered by a healthcare provider, not covered by Part D, and/or primarily covered under Part B. Classes were excluded if subject to legislative coverage mandates/restrictions, had limited therapeutic relevance to older adults, or experienced launch of a first generic, biosimilar, or authorized generic in the study period. Using Clarivate’s Fingertip Formulary database, we compared beneficiary-weighted coverage for included drugs from 2024 to 2026 across Medicare Advantage Prescription Drug (MA-PD), stand-alone Part D (PDPs), and commercial plans. We calculated absolute changes in average coverage from 2024-2026 by plan type and conducted paired Wilcoxon signed-rank tests.
RESULTS: We identified 50 drugs across nine competitive classes spanning therapeutic areas (e.g., diabetes, multiple sclerosis). Average beneficiary-weighted coverage in 2026 was highest in commercial plans (72.8%), followed by MA-PD (53.5%) and PDP plans (40.2%). Coverage declines from 2025 to 2026 were numerically largest in PDPs and smallest in commercial plans. Average coverage in PDPs declined from 53.9% in 2024 to 46.9% in 2025 (p<0.01) and further declined to 40.2% in 2026 (p<0.01). MA-PD plans experienced a decrease in coverage from 2024 (61.5%) to 2025 (57.6%; p<0.05) and from 2025 to 2026 (53.5% in 2026; p<0.05). In contrast, coverage in commercial plans remained stable in 2025 (2024: 75.0%; 2025: 74.5%; p = 0.9) and decreased by 1.7% in 2026 (72.8%; p<0.01).
CONCLUSIONS: Our findings suggest that compared to commercial plans, Medicare Part D plans experienced larger reductions in coverage of brand-only drugs in competitive classes following the Inflation Reduction Act’s formulary redesign, with the greatest declines observed in standalone PDPs.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
HPR124
Topic
Health Policy & Regulatory
Topic Subcategory
Coverage with Evidence Development & Adaptive Pathways, Insurance Systems & National Health Care, Reimbursement & Access Policy
Disease
No Additional Disease & Conditions/Specialized Treatment Areas