Medicare Part D Prescription Drug Coverage

What Part D is

Original Medicare doesn't cover most prescriptions you fill at a pharmacy. Part D fills that gap. Part D plans are sold by private insurance companies approved by Medicare, so costs and covered drugs vary from plan to plan.

There are two ways to get Part D coverage:

• A stand-alone Part D plan added to Original Medicare, usually alongside a Medicare Supplement plan
• A Medicare Advantage plan that includes drug coverage

How Part D plans are set up

Every plan follows rules set by Medicare, but each company decides the details. When you compare plans, look at:

• Premium: the monthly cost of the plan, from a few dollars to over $100
• Deductible: what you pay before the plan starts sharing costs. In 2026 it can be no more than $615, and some plans have none.
• Formulary: the list of drugs the plan covers. Every plan's list is different, so always check your medications.
• Tiers: plans sort drugs into levels, usually 4 or 5, from preferred generics up to specialty drugs. Lower tiers usually cost less.
• Pharmacies: many plans have preferred pharmacies where your costs are lower.

Plans can change their drug lists during the year within Medicare's rules, and they have to let you know about changes that affect you.

Your costs in 2026

Part D now has a yearly cap on drug costs. In 2026, once you've paid $2,100 out of pocket for covered drugs, you pay nothing more for covered drugs for the rest of the year. Covered insulin is capped at $35 for a month's supply.

You can also spread your drug costs into monthly payments through the Medicare Prescription Payment Plan, instead of paying large amounts at the pharmacy all at once.

People with higher incomes pay an extra amount (IRMAA) on top of their premium. In 2026 it applies to incomes over $109,000 for single filers or $218,000 for joint filers. If your income is limited, you may qualify for Extra Help, which lowers your drug costs.

Part D with Original Medicare

If you choose Original Medicare with a Medicare Supplement plan, you'll add a separate Part D plan. Because the two are separate, you can pick each on its own merits. One company might have the best price on your supplement while another covers your prescriptions for less. Choosing them separately can add up to real savings.

Part D with Medicare Advantage

Most Medicare Advantage plans include drug coverage, so your hospital, medical and drug benefits come from one company with one ID card, much like many employer plans. Since the drug coverage comes with the plan, check how each plan covers your medications as part of choosing it.

When you can enroll

You can join a Part D plan once you have Part A or Part B. You can sign up or switch plans only at certain times:

• Initial Enrollment Period: your 7-month window around your 65th birthday
• Annual Enrollment Period, October 15 to December 7: join, switch or drop a plan, with changes starting January 1
• Medicare Advantage Open Enrollment Period, January 1 to March 31: if you're in a Medicare Advantage plan, you can switch to another one, or return to Original Medicare and add a Part D plan
• Special Enrollment Periods: certain life events, like moving or losing employer coverage, let you make changes at other times

How to avoid the Part D late penalty

If you go 63 days or more in a row without Part D or other creditable drug coverage after your Initial Enrollment Period ends, you may owe a late penalty when you join. The penalty is 1% of the national base premium ($38.99 in 2026) for each month you went without coverage. It's added to your premium for as long as you have Part D.

Even if you don't take any medications now, a low-cost plan protects you from the penalty and from large bills if your health changes. If you have drug coverage through an employer or union, ask whether it's "creditable," meaning it's at least as good as Part D.

Get help choosing a plan

The right Part D plan depends on your exact medications, doses and pharmacy. Send us your list and we'll compare plans for you. Call 702-768-7999 to get started.