Part D Insulin Cost-Sharing Cap (Lesser of $35 or 25%)
The Part D cost-sharing cap on a covered insulin fill, plan year 2026 and later.
Open the tool → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Plan year
- 2026
- Days supply of the fill
- 90 days
- Days in a one-month supply under the plan
- 30 days
- Negotiated price for a one-month supply
- 100 dollars
Result: Cost-sharing cap for this fill: $75.00.
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What you enter
- Plan year (2026 or later)
- Days supply of the fill
- Days in a one-month supply under the plan
- Negotiated price for a one-month supply
- Maximum fair price for a one-month supply, if the insulin has one
- Cost sharing the claim charged
How this is calculated
Citation
42 CFR 423.120(h) and 423.100: for a covered insulin product, plan year 2026 and later, cost sharing per one-month supply is the lesser of $35, 25 percent of the maximum fair price and 25 percent of the negotiated price, with no deductible; a longer fill takes the fewest one-month increments. Read the sources: 42 CFR 423.120 ↗, 42 CFR 423.100 ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.