Who it's for
- People with Original Medicare, with or without a Medicare Supplement
- Anyone whose current drug plan raised prices or dropped a medicine
- People turning 65 who don't have other creditable drug coverage
- Caregivers helping a parent manage several prescriptions
What it covers
- Brand-name and generic prescription drugs on the plan's formulary
- Adult vaccines recommended by the CDC, such as the shingles vaccine, at no cost to you
- Covered insulin for no more than $35 a month
- A yearly cap on what you pay out of pocket for covered drugs
How Part D works
Part D coverage comes from private insurance companies approved by Medicare. You can get it through a stand-alone drug plan (paired with Original Medicare) or as part of most Medicare Advantage plans. Each plan has a formulary — its list of covered drugs — sorted into tiers. Lower tiers usually cost less.
Your costs depend on the plan's monthly premium, its deductible, and the copay or coinsurance for each drug's tier. Using a plan's preferred pharmacy can lower your costs further, and mail order can help with medicines you take every day.
Recent changes that help your wallet
- A yearly out-of-pocket cap. Since 2025, the law has capped what you pay for covered Part D drugs each year. The amount is adjusted annually.
- Spread your costs out. The Medicare Prescription Payment Plan lets you pay your drug costs in monthly amounts across the year instead of all at once at the pharmacy.
- Insulin and vaccines. Covered insulin costs no more than $35 a month, and recommended adult vaccines are covered at no cost to you.
How we compare drug plans
- We list every medicine you take, with the dose and how often you take it.
- We check which plans cover each drug, on what tier, and whether it needs prior authorization or has quantity limits.
- We compare the estimated yearly cost at the pharmacies you actually use.
- We review the results with you and help you enroll.
Because plans can change their drug lists and prices every year, we recommend repeating this check each fall during the Annual Enrollment Period.
Avoid the late enrollment penalty
If you go 63 days or more in a row without Part D or other creditable prescription drug coverage after your Initial Enrollment Period ends, you may owe a late enrollment penalty added to your premium for as long as you have Part D. If you have coverage through an employer or union, ask whether it's creditable, and keep the letter that says so.
Help paying for prescriptions
If your income and resources are limited, you may qualify for Extra Help, a Medicare program that lowers Part D premiums, deductibles and copays. We can help you find out whether you might qualify and how to apply through Social Security.
Common questions about Part D Drug Plans
Do I need Part D if I don't take any medicines now?
Many people still enroll in a low-cost plan to avoid a late enrollment penalty later and to be covered if they suddenly need a prescription. We'll help you weigh it.
Why did my drug costs change this year?
Plans update premiums, deductibles, drug lists and pharmacy networks every year. Your Annual Notice of Change explains what's different. Bring it to your review and we'll compare your options.
Can I switch drug plans in the middle of the year?
Usually only during certain enrollment periods, such as the Annual Enrollment Period from October 15 to December 7, unless you qualify for a Special Enrollment Period.
What if my drug isn't on the plan's list?
You and your doctor can ask the plan for an exception, or you may be able to switch to a covered alternative. When we compare plans, we look for ones that cover what you take.
