OOP Insulin Cap Stabilizes Costs, Improves Adherence

A recent national analysis showed the federal out-of-pocket cap of $35 for a 30-day insulin supply for Medicare Part D beneficiaries successfully stabilized costs and improved medication adherence, particularly among patients who previously faced the highest financial burdens. Prior to the implementation of the Inflation Reduction Act (IRA) in 2023, insulin users under Medicare often experienced significant cost volatility, with out-of-pocket expenses for a 30-day supply sometimes doubling within a single calendar year due to shifts in insurance benefit phases or deductibles.¹

For pharmacists, who often witness the clinical consequences of patients rationing doses due to cost, these findings offer compelling evidence that policy-driven price stability can directly translate into increased persistence and adherence.

About the Findings

The study, published in JAMA, found that after the cap took effect, the average out-of-pocket cost for a 30-day insulin supply dropped from $22.95 to $18.16, representing a 21% relative reduction. Perhaps more significantly for pharmacy counseling and patient planning, the within-year range of insulin costs declined by 48%, meaning patients were far less likely to encounter sticker shock at the pharmacy counter during different months of the year.¹

This stabilization was even more pronounced for those in the top decile of baseline spending—patients who previously averaged over $58 per fill—who saw their average out-of-pocket costs decline by 51% and the within-year range of those costs decrease by a staggering 75%.

This reduction in financial friction resulted in measurable improvements in clinical metrics that pharmacists track. Among the highest-cost users, 30-day insulin fills per year increased by 8%, while the proportion of days covered with basal insulin rose by 5% and persistence—defined as having no gaps in coverage—increased by 13%. These improvements show that high out-of-pocket costs have historically been linked to poor adherence, which can lead to severe complications such as ketoacidosis, kidney disease, and vision loss. The federal cap, which applied to Medicare Part D starting in January 2023 and Part B for insulin used in pumps in July 2023, is estimated to have saved approximately 1.5 million beneficiaries a total of $761 million annually.^1,2

The Role of the Pharmacist

Pharmacists should be aware of the nuances in how these caps are applied to manage patient expectations at the point of sale. Although the Medicare cap is now a federal mandate, 29 states and the District of Columbia have also implemented their own copay caps for state-regulated commercial health insurance plans. These state-level caps vary widely, ranging from $0 in New York to $100 in states like Alabama and Colorado, and some states even extend these protections to diabetes supplies and devices.³

“In my opinion, one of our biggest roles as a pharmacist on that care team is going to be education, whether that is educating the patient or even educating other members of the care team,” Jennifer Griffin, PharmD, clinical pharmacist at Harps Food Stores Inc, said.⁴ “We have so much education when it comes to these medications and insulin management, so it's important that pharmacists are empowered to speak up and share that expertise.”

Furthermore, although the Medicare cap is highly effective, some beneficiaries may still pay more than $35 if their prescription is not prorated. Current Centers for Medicare & Medicaid Services guidance generally applies the $35 rule only to full multiples of 30 days, meaning a 45-day supply could potentially be billed as a 60-day supply with a $70 charge.⁵

Despite the clear benefits of the IRA cap, researchers noted that many insulin users still experience gaps in basal insulin coverage, suggesting that while cost is a major hurdle, other barriers to adherence remain. For the uninsured population, the financial burden remains even more acute, as they previously paid more than double the national average out-of-pocket per fill.^1,2

Although some manufacturers have voluntarily implemented list price caps for certain products, the comprehensive protection provided by the Medicare cap offers a more stable framework for the millions of seniors living with diabetes. As these policies continue to evolve, the pharmacy remains the front line for ensuring that lower costs translate into the long-term health benefits intended by the legislation.^1,2

“Educating patients when it comes to these chronic disease states is going to be imperative because it's going to lead to them having better control of their conditions [and] because the patients are going to be empowered by having that knowledge,” Griffin said.⁴ “Pharmacists may also be the first to know about any problems with a medication regimen.”

READ MORE: Diabetes Resource Center

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REFERENCES

1. Myerson R, Kim NH, Romley J, et al. Insulin Costs and Use by Medicare Beneficiaries After the Inflation Reduction Act Out-of-Pocket Cap. JAMA. Published online June 06, 2026. doi:10.1001/jama.2026.5975

2. Sayed BA, Finegold K, Anders Olsen T, et al. Insulin Affordability and the Inflation Reduction Act: Medicare Beneficiary Savings by State and Demographics. Office of Health Policy. January 24, 2023. Accessed June 8, 2026. https://aspe.hhs.gov/sites/default/files/documents/bd5568fa0e8a59c2225b2e0b93d5ae5b/aspe-insulin-affordibility-datapoint.pdf

3. American Diabetes Association. State insulin copay caps. Accessed June 8, 2026. https://diabetes.org/tools-resources/affordable-insulin/state-insulin-copay-caps

4. Gallagher A, Griffin J. Q&A: community pharmacists educate patients on safe insulin use. Drug Topics. December 20, 2025. Accessed June 8, 2026. https://www.drugtopics.com/view/q-a-community-pharmacists-educate-patients-on-safe-insulin-use

5. Johns Hopkins Bloomberg School of Public Health. Medicare patients’ out-of-pocket costs for insulin decrease under mandated caps. March 19, 2024. Accessed June 8, 2026. https://publichealth.jhu.edu/2026/medicare-patients-out-of-pocket-costs-for-insulin-decrease-under-mandated-caps