Medicare Part D Explained: Costs, Coverage & 2026 Changes
TL;DR
Medicare Part D is optional prescription drug coverage sold by private insurers. In 2026, plans can charge up to a $615 deductible, and your total out-of-pocket drug spending is capped at $2,100 for the year. After that, covered drugs cost you $0. The old 'donut hole' coverage gap is gone.
Key Takeaways
- ✓Part D is optional drug coverage from private plans — a standalone PDP or built into a Medicare Advantage plan (MAPD).
- ✓2026 deductible: no plan can charge more than $615.
- ✓2026 out-of-pocket cap: once you spend $2,100 on covered drugs, you pay $0 for the rest of the year.
- ✓The 'donut hole' coverage gap no longer exists — replaced by the hard out-of-pocket cap.
- ✓You can spread drug costs into monthly payments via the Medicare Prescription Payment Plan.
- ✓Late enrollment without other creditable coverage triggers a permanent penalty — sign up when first eligible.
If you take any prescription medication, Medicare Part D is how you keep it affordable. Part D is optional coverage for prescription drugs, sold by private insurance companies that Medicare approves. You can get it as a standalone plan added to Original Medicare, or built into a Medicare Advantage plan. And in 2026, Part D is genuinely better than it's been in years — for the first time, there's a firm limit on how much you can pay out of pocket all year. Here's everything you need to know, in plain English.
What is Medicare Part D?
Part D covers the prescription drugs you pick up at the pharmacy. Original Medicare (Part A and Part B) was never designed to cover most outpatient prescriptions, so Part D fills that gap. Because it's run by private insurers, every plan has its own monthly premium, its own list of covered drugs (called a formulary), and its own network of pharmacies. There are two ways to get it: a standalone Part D plan (a "PDP") added to Original Medicare, or a Medicare Advantage plan that includes drug coverage (a "MAPD"). Most Advantage plans bundle Part D in. You generally cannot have both — adding a separate PDP while on most Advantage plans can drop you out of your Advantage plan, so check first.
How Part D works in 2026: the stages
Your drug costs move through a few stages over the year. The Inflation Reduction Act reshaped these stages and removed the old coverage gap, or "donut hole."
| Stage | Description |
|---|---|
| Stage 1: Deductible | You pay 100% of drug costs until you meet your plan's deductible (capped at $615 in 2026; some plans charge less or $0). |
| Stage 2: Initial Coverage | You pay a copay or coinsurance and the plan pays the rest. |
| Stage 3: Out-of-Pocket Cap | Once your out-of-pocket spending hits $2,100, you pay $0 for covered drugs for the rest of the year. |
That $2,100 ceiling is the headline change: no matter how costly your covered drugs are, your spending on them stops at $2,100.
SeniorPop Tip
The $2,100 cap only counts spending on drugs on your plan's formulary. Before you enroll, make sure each of your medications is covered — a cheaper premium isn't a deal if your prescription isn't on the list.
What happened to the "donut hole"?
For years, Part D had a dreaded middle phase called the coverage gap, nicknamed the donut hole, where your share of costs jumped. As of 2025 that phase was eliminated, and 2026 keeps the simpler structure. There is no donut hole anymore — just the deductible, your normal cost-sharing, and then the $2,100 cap.
What Part D costs
Monthly premium (varies by plan; higher earners pay an IRMAA surcharge); annual deductible up to $615 in 2026; copays/coinsurance during initial coverage; and $0 after you hit the $2,100 cap. Because premiums and formularies differ so much, two people in the same town can pay very different amounts for the same medication. Compare plans by your specific drug list, not just the premium.
The Medicare Prescription Payment Plan
You can now choose to spread your out-of-pocket drug costs across the year in monthly payments instead of paying a big bill at the pharmacy. It doesn't lower your total cost, but it smooths it out — helpful if an expensive prescription would otherwise hit all at once. Enrollment is free and you opt in through your drug plan.
Help paying for Part D
Extra Help (Low-Income Subsidy) lowers or eliminates your Part D premium, deductible, and copays. Medicare Savings Programs help pay Medicare costs and can open the door to Extra Help. Manufacturer and pharmacy patient-assistance programs can help with specific drugs.
Don't get the late-enrollment penalty
If you go 63 or more days without Part D or other creditable drug coverage after you're first eligible, you can owe a permanent late-enrollment penalty added to your premium for as long as you have Part D. Even if you take no medications today, it's often worth enrolling in a low-cost plan when first eligible to avoid the penalty later.
How to choose a Part D plan
- List your medications (exact names and doses).
- Check each plan's formulary to confirm coverage and tier.
- Compare total annual cost (premium + deductible + copays for your drugs), not just premium.
- Check the pharmacy network (preferred pharmacies mean lower copays).
- Review every fall — plans change formularies and prices each Open Enrollment (Oct 15–Dec 7).
Not sure where to start? SeniorPop can help you see which plans cover your medications and fit your budget.
Disclaimer
SeniorPop is a private resource and is not affiliated with or endorsed by Medicare or any government agency. Figures reflect 2026 Medicare amounts published by CMS and Medicare.gov; verify specifics at Medicare.gov.
Frequently Asked Questions
Disclaimer: SeniorPop is not affiliated with Medicare, Medicaid, or any government agency. Benefit availability varies by plan and location.