Plan D is a prescription drug coverage option, but it no longer exists as a standalone choice

Plan D was a Medicare prescription drug plan that ran from 2006 to 2007. It is no longer offered. If you see "Plan D" mentioned in old materials or hear it in conversation, the person is referring to a plan that ended nearly two decades ago.

What exists now are Part D plans — the prescription drug coverage that Medicare created in 2006 and continues to offer today. The letter changed, but the concept remained: private insurance companies run these plans under Medicare rules, and they cover medications you take at home. Part D is what you would actually be looking at if you need prescription drug coverage through Medicare right now.

The confusion happens because the original program included Plan A, Plan B, Plan C, and Plan D as four separate options. Medicare discontinued those letter names and moved to a different structure. Understanding what happened and what your actual options are now will save you time when you are shopping for coverage.

Key Takeaways

  • Plan D ended in 2007 and is not available; if you need prescription drug coverage now, you are looking at Part D plans instead.
  • Part D is the current prescription drug program run by private insurers under Medicare, and it covers medications filled at pharmacies.
  • Part D plans vary by insurer, cost, and which drugs they cover, so comparing plans in your area each year matters.
  • You can enroll in Part D when you first become may be able to access for Medicare, during the annual enrollment period, or if you miss the important date and face a penalty.

Why Plan D disappeared and what replaced it

When Medicare Part D launched in 2006, the program offered four standardized prescription drug plans with letter names: A, B, C, and D. Plan D was the most comprehensive of the four — it covered the widest range of drugs and had the highest out-of-pocket costs for the person using it. Insurers offered these plans nationwide, and the structure was meant to be straightforward and consistent.

By 2008, Medicare changed the system. The letter-named plans were phased out, and insurers began designing their own Part D plans with their own names and structures. This shift gave insurers more flexibility to compete on price and coverage, but it also made the plans harder to compare. Today, there is no Plan D option at all — only individual Part D plans offered by companies like UnitedHealthcare, Humana, CVS Caremark, and others.

If someone tells you they have "Plan D," they either have an old plan that was grandfathered in (very rare) or they are using outdated language to describe their current Part D coverage. The substance of what they have — prescription drug insurance through Medicare — is the same, but the name and structure are different.

How Part D plans work today

Part D is prescription drug coverage you can add to Original Medicare (Parts A and B) or to a Medicare Advantage plan. You pay a monthly premium, and the plan covers medications you fill at participating pharmacies. The plan also covers some mail-order and online pharmacies.

Every Part D plan has a formulary — a list of drugs the plan covers. Not all plans cover the same medications, and the cost you pay for a specific drug depends on which plan you choose. This is why two people taking the same medication can pay very different amounts depending on their plan.

Part D plans also have a standard structure for how much you pay out of pocket. You pay a monthly premium, then a copay or coinsurance for each prescription until you reach a certain amount in out-of-pocket costs. Once you hit that limit, the plan covers most of the cost of your medications for the rest of the year. The exact amounts change each year.

Comparing Part D plans in your area

Because Part D plans vary by insurer and by region, the plan available to you in one state may not be available in another, and the cost of the same drug can differ between plans. Medicare provides a tool called the Plan Finder on Medicare.gov where you can enter your medications and see which plans cover them and what you would pay.

You do not have to use the same plan year after year. Every year during the annual enrollment period (October 15 to December 7), you can switch to a different Part D plan if a better option becomes available or if your medications change. Many people's costs go up or down from year to year, so checking your options annually is worth the time.

When you compare plans, look at the monthly premium, the copays for your specific drugs, and whether your pharmacy is in the plan's network. A plan with a low premium might have high copays, while a plan with a higher premium might cover your medications more cheaply overall. The Plan Finder will show you the total estimated cost for the year based on your medications, which makes comparison easier.

When you can enroll in Part D

You can enroll in Part D when you first become may be able to access for Medicare, usually at age 65. If you enroll during your initial enrollment period (the three months before, the month of, and the three months after your 65th birthday), there is no penalty.

If you miss that window, you can still enroll during the annual enrollment period each October through December. However, if you go without Part D coverage for more than 63 days after you become may be able to access, Medicare charges you a late enrollment penalty — an extra amount added to your premium for as long as you have Part D coverage. The penalty is calculated based on how long you went without coverage.

There are exceptions: if you have coverage through an employer or union, or if you have coverage through another source that is as good as Part D (called creditable coverage), you can delay enrollment without penalty. You will need to show proof of that coverage when you do enroll.

Part D costs and what you pay

Part D premiums vary widely depending on the plan and your location. In 2024, premiums range from roughly $7 to $100 per month, though the exact amount depends on which plan you choose and where you live. The monthly premium is separate from what you pay when you fill a prescription.

When you fill a prescription, you pay a copay (a fixed amount like $5 or $15) or coinsurance (a percentage of the drug's cost). The amount depends on the plan and the drug's tier — plans typically have three to five tiers, with generic drugs on lower tiers and brand-name drugs on higher tiers. As you fill prescriptions throughout the year, these copays add up toward your out-of-pocket limit.

Once your out-of-pocket costs reach a certain amount (in 2024, that limit is $7,050), the plan covers 95 percent of the cost of your medications for the rest of the year. This protection is important if you take expensive medications or have a serious illness that requires multiple prescriptions.

What to do if you have old Plan D paperwork

If you have documents, letters, or insurance cards that mention "Plan D," check the date. If the documents are from 2007 or earlier, they are outdated and do not describe your current coverage. If you are currently enrolled in a Part D plan, your current plan documents and your insurance card will show the plan name and the insurer — not a letter designation.

If you are unsure what coverage you have now, call the number on your Medicare card or visit Medicare.gov and log into your account. You can see your current coverage there, including which Part D plan you are in (if you have one). If you do not have Part D coverage and think you need it, you can check your options using the Plan Finder tool.

Frequently Asked Questions

Is Plan D the same as Part D?

No. Plan D was a specific Medicare prescription drug plan that ended in 2007. Part D is the current prescription drug program that Medicare offers today. The names are similar, which causes confusion, but they are different things. If you need prescription drug coverage now, you are looking at Part D plans.

Can I still enroll in Plan D?

No, Plan D is not offered anymore. If you need prescription drug coverage, you can enroll in a Part D plan during your initial enrollment period when you turn 65, or during the annual enrollment period from October 15 to December 7 each year. If you miss these windows, you may face a late enrollment penalty.

What if my doctor prescribed a medication that my Part D plan does not cover?

You can ask your doctor to prescribe a different medication that is on your plan's formulary, or you can request an exception from the plan. Many plans will cover a non-formulary drug if your doctor submits a request explaining why that specific medication is medically necessary. The process usually takes a few days to a week.

Do I have to switch Part D plans every year?

No, you can keep the same plan if you want to. However, your costs and coverage may change from year to year, and new plans may become available. Checking your options during the annual enrollment period helps you find the plan that costs the least for your current medications.

What happens if I do not enroll in Part D when I am first may be able to access?

If you go more than 63 days without Part D coverage after you become may be able to access, you will owe a late enrollment penalty for as long as you have Part D. The penalty is based on how long you went without coverage. The only exception is if you had creditable coverage through an employer, union, or another source during that time.