What Part D covers
Part D is prescription drug coverage sold by private insurers approved by Medicare. It covers brand-name and generic medications based on the plan's formulary (drug list). You can get it as a standalone plan alongside Original Medicare, or bundled into a Medicare Advantage plan (called an MA-PD).
The four coverage stages
Part D costs move through four stages during the year, and where you are determines what you pay:
- Deductible — you pay full price until you meet the plan's annual deductible (up to about $615 in 2026).
- Initial coverage — you pay copays or coinsurance and the plan pays the rest.
- Coverage gap — the old "donut hole." Under the Inflation Reduction Act, your costs in this phase are now sharply reduced.
- Catastrophic — once you hit the annual out-of-pocket cap, you pay $0 for covered drugs the rest of the year.
The out-of-pocket cap is a big deal
There's now a hard annual cap on what you pay out of pocket for covered Part D drugs — about $2,100 in 2026 — ending the era of unlimited exposure for people on expensive medications. You can also spread that spending across the year in monthly installments through the Medicare Prescription Payment Plan. If you take high-cost drugs, this changes the math on which plan is right for you.
Your drug list is the whole game
Two plans with similar premiums can differ by thousands of dollars a year once you account for how each covers your specific medications. When we compare plans for you, we check four things: that your drugs are on the formulary (and on a low tier), that your preferred pharmacy is in-network, the true total cost (premium + deductible + copays — not just the premium), and the plan's Medicare star rating. We run your exact list through every available plan to find the lowest total annual cost — it's part of our free service.
Standalone vs. bundled — and Extra Help
A standalone Part D plan pairs with Original Medicare + Medigap and lets you choose your drug coverage independently. An MA-PD bundles drugs into your Advantage plan for convenience, but ties you to that plan's formulary and pharmacy network.
If your income and resources are limited, you may qualify for Extra Help (the Low-Income Subsidy) — a federal program that pays part or all of your Part D premiums, deductibles, and copays. Call Social Security at 1-800-772-1213 or ask us to check whether you qualify.