Part D, decoded
The $2,100 drug cap: what counts, what doesn’t, and where the donut hole went
Short answer: once your out-of-pocket spending on covered Part D drugs reaches $2,100 in 2026, you pay $0 for covered drugs for the rest of the year. The donut hole is gone for good. The two words carrying all the weight in that sentence are "covered" and "Part D," and this article maps exactly what falls inside and outside them.
Key takeaways
- The 2026 Part D out-of-pocket cap is $2,100, up from $2,000 in 2025; after you reach it, covered drugs cost $0 for the rest of the year.
- Plans may charge a deductible of up to $615 in 2026; after it, you typically pay 25% cost-sharing until the cap.
- Only drugs on your plan’s formulary count toward the cap; non-covered drugs cost full price with no ceiling.
- The Medicare Prescription Payment Plan lets you spread out-of-pocket costs into equal monthly installments.
- Insulin is capped at $35 a month and recommended vaccines are free, on every Part D plan.
The three phases of a 2026 drug year
| Phase | What you pay | When it ends |
|---|---|---|
| Deductible | 100% of covered drug costs | When you’ve paid your plan’s deductible (up to $615; many plans charge less or $0) |
| Initial coverage | Typically 25% cost-sharing, or your plan’s copays | When your own out-of-pocket spending on covered drugs reaches $2,100 |
| Catastrophic | $0 for covered drugs | December 31, then everything resets |
Standard 2026 Part D benefit design. Individual plans can be more generous at each stage but not less.
For anyone on expensive brand-name drugs, this is the most protective change in Medicare in a generation. Under the pre-2025 design, the catastrophic phase still charged coinsurance with no ceiling at all; five-figure annual drug bills were routine for specialty medications. Now the worst legal case for covered drugs is $2,100 plus premiums.
The famous donut hole (the coverage gap where cost-sharing used to spike mid-year) was eliminated in 2025 and stays gone in 2026. If you’ve been budgeting around it from memory, retire that mental model.
A worked example
Say your plan has the full $615 deductible and one of your medications is a brand drug with a $900 monthly retail price.
- January: you pay $615 (deductible met mid-fill), then 25% of the remainder. Out of pocket so far: roughly $686.
- February through part of July: $225 a month (25% of $900) until your cumulative out-of-pocket hits $2,100, which lands mid-summer.
- Rest of the year: $0 for that drug and every other covered drug.
Total for the year: $2,100, no matter whether the drug costs $900 or $9,000 a month. That predictability is the whole point, and it’s also why the next section matters so much.
"Covered" is doing heavy lifting
The cap applies to drugs on your plan’s formulary. A drug your plan doesn’t cover contributes nothing toward the cap, and you pay its full price with no ceiling. Two plans with identical premiums can produce wildly different years for the same prescription list purely on formulary differences.
Practical consequences: run your exact drug list through Medicare.gov’s plan finder every fall before letting a plan auto-renew, because formularies change each January; and if a drug you need isn’t covered, your plan has a formal exception process where your prescriber attests medical necessity. A granted exception makes the drug count as covered, cap included. Denials can be appealed, and the appeal deadlines are printed on the denial letter for a reason.
What sits outside the cap entirely
- The GLP-1 Bridge. The new $50-a-month weight-loss drug program runs outside Part D. Those payments never touch your $2,100. (Full explainer here.)
- Part B drugs. Medications administered in a doctor’s office or infusion center (many cancer drugs, injections) usually bill under Part B, with its own 20% coinsurance that a Medigap plan, not the drug cap, addresses.
- Non-formulary drugs without an exception, as above.
- Premiums. Your monthly plan premium doesn’t count toward the cap.
Two floors that help everyone regardless of the cap: insulin is capped at $35 a month on every plan, and recommended adult vaccines (like shingles) are free under Part D.
Smoothing: pay monthly instead of all at once
Every plan must offer the Medicare Prescription Payment Plan, which spreads your out-of-pocket drug costs into equal monthly payments across the calendar year instead of charging them at the counter. If a January fill would otherwise cost you the full $2,100 at once, opting in turns that into roughly $175 a month.
Be clear-eyed about what it is: a payment plan, not a discount. It changes when you pay, not how much. It shines for people on fixed monthly budgets facing front-loaded costs; it adds nothing if your spending is already spread evenly. You opt in through your plan, and you can do so before the year starts or mid-year.
Why healthy people should still carry a drug plan
The Part D late enrollment penalty is 1% of the national base beneficiary premium ($38.99 in 2026) for every month you went without creditable drug coverage after becoming eligible, added to your premium permanently and recalculated as the base premium rises. Skip coverage for three years because you take nothing, and you’ve bought a 36% surcharge on every drug plan for the rest of your life. A $0-premium plan you never use is penalty insurance, and it also means that the year a specialist writes you an expensive prescription, the $2,100 ceiling is already in place instead of a year away.
Questions people also ask
What is the Medicare drug out-of-pocket cap in 2026?
Is the Medicare donut hole gone?
Do all my prescriptions count toward the $2,100 cap?
Can I spread my Medicare drug costs over the year?
Is insulin really $35 a month on Medicare?
Sources for this article
- Medicare.govHow much does Medicare drug coverage cost: the phase structure, the penalty formula, and the $38.99 national base premium.
- CMS.gov2026 premiums and deductibles announcement: companion 2026 amounts referenced here.
- Medicare.govMedicare Plan Finder: the official tool for testing your drug list against real plan formularies.
Figures checked against these sources in July 2026. We update within weeks when CMS publishes new amounts.