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Medicare Part D Drug Cost Estimator

See month-by-month how your prescription spending moves through the deductible, the 25% coinsurance phase, and the $2,100 out-of-pocket cap for 2026 — no sign-up required.

Your Plan & Drug Costs

Based on the CMS standard Part D benefit design for 2026. Your actual plan may have a lower deductible or different tiers — check your Evidence of Coverage for exact numbers.

Add up the full retail price of everything you fill each month — not your copay. Check the drug price tool for individual prices.
Some Part D plans waive the deductible on generics or lower tiers.
New Medicare enrollees mid-year still get a full deductible/cap cycle.
Deductible phase — you pay 100% Initial coverage — you pay 25% Catastrophic — you pay $0
$0Total You'll Pay This Year
$0Saved vs. Paying Retail
—Month You Hit the $2,100 Cap
$0Average Monthly Cost

Month-by-Month Breakdown

MonthPhaseRetail CostYou PayCumulative OOPPlan Pays

How the 2026 Medicare Part D Benefit Works

The Inflation Reduction Act eliminated the old "donut hole" coverage gap starting in 2025. The redesigned Part D benefit now has three phases, and this calculator walks your spending through all three:

1. Deductible

You pay 100% of drug costs until you've spent the annual deductible ($615 standard for 2026).

2. Initial Coverage

You pay 25% coinsurance; your plan pays the rest — until your total out-of-pocket spending hits $2,100.

3. Catastrophic

Once you've spent $2,100 out of pocket, you pay $0 for covered Part D drugs for the rest of the calendar year.

What Counts Toward the $2,100 Cap?

Your deductible payments and 25% coinsurance both count toward the $2,100 true out-of-pocket (TrOOP) threshold. Manufacturer discounts on brand-name drugs in the coverage phase also count toward TrOOP under current rules — this calculator assumes your own cash/coinsurance payments only, so if you take expensive brand-name drugs you may hit the cap faster than shown here.

Why This Matters More for Some Drugs

If your monthly drug costs are high — GLP-1 medications, specialty drugs, or several brand-name maintenance medications — you're likely to blow through the deductible and coinsurance phases in just a few months and spend most of the year paying $0. If your costs are low, you may stay in the 25% coinsurance phase the entire year and never reach the cap.

About This Estimator

This tool models the CMS standard Part D benefit design published for 2026 (deductible, coinsurance rate, and out-of-pocket threshold). Actual Part D plans vary — some have $0 deductibles, different drug tiers, or additional supplemental coverage. This is a planning estimate, not a guarantee of your actual costs. For your specific plan's numbers, check your plan's Evidence of Coverage or Medicare.gov's Plan Finder.

If You Might Qualify for Extra Help

Medicare's Extra Help program (also called the Low-Income Subsidy) can significantly reduce or eliminate the deductible and coinsurance shown by this calculator for beneficiaries who qualify based on income and resources. This tool does not model Extra Help — it only shows the standard benefit design. If your income is limited, it's worth checking your eligibility directly through the Social Security Administration or your State Health Insurance Assistance Program (SHIP) before assuming the standard numbers here apply to you.

What This Estimator Doesn't Account For

This calculator assumes a flat monthly retail drug cost and the CMS standard benefit phases — it doesn't model drug-tier-specific coinsurance, a plan's separate premium, mid-year drug changes, or manufacturer discounts that may apply differently depending on whether a drug is brand-name or generic. Those factors can shift exactly when you reach the $2,100 cap. Treat the month shown here as a reasonable planning estimate, not an exact date, and confirm actual phase transitions with your plan's member portal or Explanation of Benefits.

Frequently Asked Questions

What is the Medicare Part D deductible in 2026?
The standard Medicare Part D deductible for 2026 is $615. Some plans set a lower deductible, and some drugs may be exempt from it — check your specific plan's Evidence of Coverage.
What is the Medicare Part D out-of-pocket cap for 2026?
For 2026, once your true out-of-pocket (TrOOP) drug spending reaches $2,100, you enter the catastrophic coverage phase and pay $0 for covered Part D drugs for the rest of the calendar year.
Is there still a Medicare Part D donut hole in 2026?
No. The coverage gap ("donut hole") was eliminated under the Inflation Reduction Act's Part D redesign, effective 2025. Coverage now moves directly from the deductible phase, to a 25% coinsurance phase, to a $0 catastrophic phase once the annual out-of-pocket cap is reached.
Does this calculator know my actual Part D plan?
No. It models the CMS standard benefit design, not any specific insurer's plan. Real plans can have a $0 deductible, different drug tiers, or supplemental coverage that changes these numbers — use this as a planning estimate and confirm the specifics with your plan's Evidence of Coverage.
What if I qualify for Extra Help (the Low-Income Subsidy)?
Extra Help can substantially lower or eliminate the deductible and coinsurance modeled here for beneficiaries who qualify based on income and resources. This calculator doesn't account for Extra Help — check your eligibility through the Social Security Administration or your State Health Insurance Assistance Program (SHIP) rather than relying on the standard-benefit numbers shown above.
Does this calculator store or sell my information?
No. Every calculation runs in your browser using only the numbers you enter — nothing is sent to a server or saved. See our Privacy Promise page for the full policy.

Also Compare Cash Prices

If you're not yet on Medicare, or want to compare cash vs. plan pricing, use our full drug price tool.

Compare Drug Prices →