Medicare Part D is prescription drug coverage you add to Original Medicare

Medicare Part D is optional prescription drug insurance run by private companies approved by Medicare. You add it to Original Medicare (Parts A and B) to cover the cost of prescription medications. You do not sign up for Part D through Medicare directly — instead, you choose a plan from an insurance company, and that company handles your enrollment.

The process takes about 15 minutes online or over the phone, and coverage can start as soon as the first day of the following month. The important date to sign up without a penalty is December 7 each year, though you can join outside that window if you have a may have access to life event like losing other drug coverage.

Key Takeaways

  • You sign up for Part D through an insurance company's website or by phone, not through Medicare.gov, though Medicare.gov has a tool to compare plans in your area.
  • You need your Medicare card and Social Security number to sign up, plus a list of your current medications to find a plan that covers them at the lowest cost.
  • The annual enrollment period runs October 15 through December 7, and plans take effect January 1 of the following year.
  • If you miss the December 7 important date and do not have other drug coverage, you will pay a penalty added to your premium for as long as you have Part D.
  • You can change plans once a year during the enrollment period, or when ready if you lose other drug coverage or move to a different state.

Gather your Medicare card and medication list before you start

Before you contact an insurance company, have your Medicare card in front of you. You will need your Medicare number, which is printed on the card. You will also need your Social Security number.

Write down every prescription medication you take right now, including the name of the drug, the dose, and how often you take it. If you are not sure of the exact dose, call your pharmacy or doctor's office — they can tell you in one call. This list matters because different plans cover different drugs at different prices. A plan that is cheap for one person's medications can be expensive for another's.

Use Medicare.gov to compare plans in your area

Go to Medicare.gov and click "Find Care Providers & Suppliers" or search for "Medicare Plan Finder." Enter your ZIP code and the current date. The tool will show you every Part D plan available where you live, ranked by estimated yearly cost based on your medications.

The tool shows you the monthly premium (what you pay each month), the deductible (what you pay before the plan starts paying), and how much you will pay out of pocket for each of your medications. Some plans have no deductible. Some plans charge different amounts depending on which pharmacy you use. Read the details for at least three plans before you decide.

Write down the name of the insurance company and the plan name for the plan you want to join. You will need this information when you sign up.

Sign up directly with the insurance company

Once you have chosen a plan, contact the insurance company to enroll. You can do this online through the company's website, by phone, or by mail. Most companies let you sign up online in about 15 minutes.

Have your Medicare card, Social Security number, and the plan name ready. The company will ask you to confirm your name, date of birth, and address. They will ask whether you have other drug coverage (from a current or former employer, a union, or the Veterans Administration). Answer honestly — if you have other coverage, you may not need Part D, and signing up could cost you money.

After you submit your information, the company will send you a confirmation number. Write this down. You should receive your insurance card in the mail within two weeks.

Know the enrollment important date and penalties for late sign-up

The main enrollment period is October 15 through December 7 each year. Plans you sign up for during this window take effect January 1 of the following year. If you sign up in November, your coverage starts January 1. If you sign up in December, your coverage still starts January 1 — there is no advantage to signing up early.

If you miss December 7 and you do not have other drug coverage, you will pay a late enrollment penalty. This penalty is added to your monthly premium for as long as you have Part D. The penalty is calculated based on how many months you went without coverage, and it increases each year. For example, if you go six months without signing up, your penalty will be roughly six months' worth of the national average premium, added to whatever plan you eventually choose.

You can avoid the penalty if you have other drug coverage — from an employer, a union, TRICARE, the Veterans Administration, or a state program. If you lose that coverage, you have 63 days to sign up for Part D without a penalty. Keep documentation of when your other coverage ended.

Change your plan once a year or after a may have access to life event

You can switch to a different Part D plan once a year during the October 15 through December 7 enrollment period. The new plan takes effect January 1. You do not have to do anything to keep your current plan — if you do not switch, your coverage continues.

You can also switch plans when ready if you have a may have access to life event: you lose other drug coverage, you move to a different state, your plan leaves the market, or your plan stops covering one of your medications. Contact your current insurance company or call Medicare at 1-800-MEDICARE to report the change and switch plans.

What happens after you sign up

Your insurance company will mail you an insurance card within two weeks of enrollment. Use this card at the pharmacy when you pick up prescriptions. If you do not receive your card by January 1, call the insurance company to ask for a temporary card number you can use at the pharmacy.

Your first month's premium is usually due by the first day of your coverage month. The insurance company will tell you how to pay — most accept online payments, automatic bank withdrawals, or checks mailed to an address on your bill.

After you have had the plan for a few weeks, review your first prescription bills to make sure the plan is covering your medications the way the Medicare Plan Finder said it would. If something is wrong, call your insurance company right away.

Frequently Asked Questions

What if I do not take any prescription medications right now?

You can still sign up for Part D. Even if you do not take medications now, you may need them later, and signing up before you need them avoids the late penalty. Some plans have low or no monthly premiums if you do not use them.

Can I sign up for Part D if I have coverage through my job?

You can, but you do not have to. If your employer's plan covers drugs as well as or better than Part D, you may not need it. Check your employer's plan documents or call your benefits office. If you drop your employer coverage later, you have 63 days to sign up for Part D without a penalty.

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

Contact your insurance company and ask for an exception. Many plans will cover a medication not on their list if your doctor writes a letter explaining why you need it. This process usually takes a few days. If the exception is denied, you can ask your doctor to prescribe a similar medication that the plan does cover.

Do I have to use a specific pharmacy?

Most Part D plans work at any pharmacy in their network, which includes most large chains and independent pharmacies. Some plans charge less if you use a mail-order pharmacy for 90-day supplies. Check your plan documents to see which pharmacies are in the network and what the costs are.

What if I move to a different state?

Your current Part D plan may not be available in your new state. Contact your insurance company as soon as you know your move date. You can switch to a plan available in your new state when ready, without waiting for the annual enrollment period.