Summary: Medicare Part D in 2026 works like this: you pay your monthly premium, then a $615 deductible on covered drugs, then 25 percent of drug costs until your out-of-pocket spending hits the $2,100 annual cap. After that, covered drugs cost you $0 for the rest of the year. This calculator estimates your total yearly Part D cost from your premium and your drugs' retail cost, including the $35-a-month insulin cap.
Uses the 2026 CMS standard benefit. Your plan's formulary tiers will differ. For planning only.
The Inflation Reduction Act redesigned Part D, and the old vocabulary is obsolete. The donut hole, the coverage gap where you once paid a higher share mid-year, was eliminated starting in 2025. The 2026 benefit has three phases: the deductible ($615), initial coverage where you pay 25 percent, and catastrophic coverage where you pay $0 after your out-of-pocket hits $2,100. That cap is the single most important number in the program.
Premiums are separate from the cap. The national base beneficiary premium for 2026 is $38.99 a month, and CMS projected the average standalone plan premium at about $34.50. Your premium does not count toward the $2,100 cap, which surprises people every year. The calculator adds premiums and drug out-of-pocket separately so you see the true total.
Two more 2026 facts worth knowing: insulin is capped at $35 a month and is exempt from the deductible, and the late enrollment penalty is 1 percent of the base beneficiary premium for every month you went without creditable drug coverage. The penalty is permanent, which makes the enroll-on-time decision more valuable than most plan-shopping decisions.
The 2026 standard benefit: up to a $615 deductible, 25% coinsurance on covered drugs after that, and a $2,100 annual out-of-pocket cap. Premiums average about $34.50 a month for standalone plans; the national base premium is $38.99.
$2,100 for covered Part D drugs, up from $2,000 in 2025. Once your out-of-pocket spending reaches it, covered drugs cost $0 for the rest of the year. Premiums do not count toward the cap.
No. The coverage gap (donut hole) was eliminated under the Inflation Reduction Act starting in 2025. You now pay 25% after the deductible until you hit the out-of-pocket cap.
1% of the national base beneficiary premium ($38.99 in 2026) for each full month you were eligible but lacked creditable drug coverage, added to your premium permanently.
Figures: CMS 2026 Part D standard benefit parameters. Verify plan details in your plan's formulary. This page is for planning only.