The Inflation Reduction Act capped out-of-pocket insulin costs for Medicare beneficiaries at $35, a policy that took effect in 2023. A study observed that this cap was associated with reduced and more stable out-of-pocket insulin costs for beneficiaries.
Researchers from Emory University, the University of Southern California, and the University of Wisconsin-Madison conducted an analysis of insulin costs and usage for over 2.8 million Medicare Part D beneficiaries using insulin. The study compared out-of-pocket costs, 30-day insulin fills, adherence rates, and persistence levels before and after the policy's implementation. For the overall study cohort, out-of-pocket insulin costs decreased by approximately $5 per 30-day supply, which represents a decrease of about 21 percent.
A group of approximately 250,000 people, identified as having pre-policy insulin costs of at least $58 per 30-day supply, saw an 8 percent increase in 30-day insulin fills. For this same high-cost group, the proportion of days covered increased by 5 percent. "Insulin users who previously faced high insulin costs improved their adherence to insulin after the cap, suggesting they had been skipping doses to save money. However, many Medicare patients already paid low prices. Future out-of-pocket caps will have the largest impact if they can target patients facing high out-of-pocket costs, such as people who are uninsured," said Rebecca Myerson, an associate professor of health policy and management.
"Making sure patients take their medication should be a greater clinical priority. This research demonstrates a powerful policy lever for doing so: reducing their out-of-pocket costs," said Dana Goldman, founding director of the USC Schaeffer Institute for Public Policy & Government Service.
The research analysis indicated that during 2021 and 2022, only 13 percent of Medicare Part D insulin fills would have exceeded the $35 cap. Most Medicare Part D insulin users had previously qualified for existing affordability programs, including the Senior Savings Model and the Low-Income Subsidy Program. Beneficiaries who experienced the most benefit from the cap were disproportionately non-Hispanic white, male, aged 65 to 75, enrolled in fee-for-service insurance, and less likely to reside in urban areas. This research was funded by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases. Data from the IQVIA Institute indicates that a universal $35 cap on all insulin prescriptions would have saved insulin users in the U.S. $170 million in out-of-pocket costs in 2024.