Medicare Part D

Part D in 2026: New $2,100 Cap and How It Works

Londonderry, N.H. — If you take prescription drugs and have Medicare, 2026 brings the biggest change to Part D in years. There's now a firm ceiling on what you pay out of pocket each year, and the old "donut hole" is gone for good. Here's a plain-language walkthrough of how Part D works this year, what the numbers mean, and where to get answers you can trust.

The big headline: a $2,100 out-of-pocket cap

Starting in 2026, no one with a Medicare Part D plan will pay more than $2,100 out of pocket for covered prescription drugs in a calendar year. Once your spending on covered drugs reaches that cap, you pay $0 for the rest of the year for those prescriptions.

This cap is set by Medicare and applies across all Part D plans, whether you get drug coverage through a stand-alone Part D plan or bundled inside a Medicare Advantage plan. It's the same number in Londonderry as it is anywhere else in the country. (Source: CMS — Medicare Part D program rules, medicare.gov.)

The three phases of Part D in 2026

Since 2025, Part D has had three phases instead of four. The old coverage gap — often called the donut hole — no longer exists. Here's how a year of drug coverage flows now:

1. The deductible phase. If your plan has a deductible, you pay the full negotiated price for your drugs until you meet it. For 2026, the maximum deductible any Part D plan can charge is $615. Plans can set a lower deductible, or none at all — but no plan can go higher than that ceiling.

2. The initial coverage phase. After the deductible, you pay a copay or coinsurance for each prescription, and your plan pays the rest. You stay in this phase until your out-of-pocket spending hits the annual cap.

3. The catastrophic phase. Once you've spent $2,100 out of pocket on covered drugs, you're done paying for covered prescriptions for the rest of the calendar year. Your share drops to $0.

That's it. Three phases, one clear finish line.

The Medicare Prescription Payment Plan: spreading costs out

Even with a $2,100 cap, hitting a big drug bill in January can sting. That's why Medicare offers the Medicare Prescription Payment Plan — sometimes called "M3P" or drug cost smoothing.

If you opt in, you don't pay the pharmacy directly at the counter for covered drugs. Instead, your plan bills you monthly, spreading your out-of-pocket costs across the rest of the year. It doesn't lower what you owe overall, but it can make a large one-time bill easier to manage. Enrollment is optional and free, and you can ask your plan about signing up.

What this looks like in Londonderry

Londonderry is in Rockingham County, which is where Medicare sets plan availability for local residents. The rules and dollar figures above — the $2,100 cap, the $615 maximum deductible, the three phases — apply the same way whether you live on Mammoth Road or anywhere else in town.

If you want to see exactly which Part D and Medicare Advantage plans are offered in Rockingham County, the Plan Finder tool at medicare.gov lets you enter your ZIP code and compare options side by side, including how each plan covers your specific medications.

A quick word on higher-income surcharges (IRMAA)

Most people pay only their plan's Part D premium. But if your income is higher, you may owe an extra amount called IRMAA (Income-Related Monthly Adjustment Amount) on top of it. For 2026, IRMAA surcharges kick in when a single filer's income is above $109,000 (higher thresholds apply for married couples filing jointly). Social Security notifies you if this applies, based on your tax return from two years earlier.

Key dates to keep on the fridge

• October 15 – December 7: Medicare Annual Enrollment Period. You can join, switch, or drop a Part D or Medicare Advantage plan. Changes take effect January 1.
• January 1 – March 31: Medicare Advantage Open Enrollment Period. If you're already in a Medicare Advantage plan, you get one chance to switch to another Advantage plan or return to Original Medicare with a Part D plan.

Outside these windows, you generally need a Special Enrollment Period (for example, if you move or lose other coverage) to make changes.