When and how to enroll in Medicare Part D

You enroll in Medicare Part D during your Initial Enrollment Period, which runs for seven months starting the month you turn 65 or the month you first become may be able to access for Medicare. The enrollment window includes the month before you turn 65, the month itself, and three months after. If you miss this window, you can still enroll during the Annual Enrollment Period from October 15 to December 7 each year, but you may face a permanent penalty on your premiums if you wait.

You can enroll through three routes: online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. The online route is fastest — you can compare plans, see your costs, and submit your choice in one session. By phone, a Medicare representative walks you through the same options but takes longer. In person, you bring your Medicare card and any documents showing your current prescriptions, and staff help you choose.

The enrollment itself takes 10 to 15 minutes once you have decided which plan you want. Your coverage starts the first day of the month after you enroll, unless you enroll between November 1 and December 7, in which case coverage starts January 1.

Key Takeaways

  • Your Initial Enrollment Period is seven months long, starting the month before you turn 65, and missing it triggers a permanent penalty unless you have creditable coverage from an employer or union.
  • You enroll online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office — online is fastest.
  • Before you enroll, gather a list of your current medications and their doses, because your out-of-pocket costs vary sharply by plan.
  • Coverage starts the first day of the month after you enroll, or January 1 if you enroll between November 1 and December 7.
  • You can change plans once per year during the Annual Enrollment Period (October 15 to December 7) if your medications or costs change.

What documents and information you need before enrolling

Gather your list of current medications before you start the enrollment process. Include the name of each drug, the dose (for example, 10 mg), and how many times per day you take it. This list is the single most important thing you bring to enrollment, because your out-of-pocket costs — copays, coinsurance, and deductibles — depend entirely on which drugs are on each plan's formulary and at what tier.

You will also need your Medicare card, which shows your Medicare number. If you are enrolling online, you can have your card in front of you but do not need to type the number — Medicare.gov recognizes you through your Social Security number and date of birth. If you are enrolling by phone or in person, having the card makes the process slightly faster.

If you take multiple medications or have complex prescriptions, print or write down the pharmacy you currently use. Some plans have preferred pharmacies that charge less, and knowing your pharmacy in advance helps you check whether it participates in the plan you are considering.

Step-by-step enrollment at Medicare.gov

Go to Medicare.gov and select "Find Care Providers & Compare Plans" from the homepage. Click "Compare Medigap, Medicare Advantage, and Part D plans." You will be asked to log in or create a Medicare.gov account. Use your email address and a password you create — you do not need your Medicare number to set up the account, though you will verify your identity later.

After you log in, enter your zip code and select your state. Medicare will show you all Part D plans available in your area. Enter your list of medications into the drug search tool — type the name of each drug, and the tool will show you the cost under each plan. The tool displays your estimated yearly out-of-pocket cost for each plan, which includes premiums, deductibles, copays, and coinsurance.

Compare at least three plans. Look not just at the yearly cost but at the structure: some plans have a low premium but high copays, while others have a higher premium but lower copays. If you use the same pharmacy regularly, check whether it is in-network for each plan. Once you have chosen, click "Enroll" on that plan's page. You will confirm your personal information, review the plan details one more time, and submit your enrollment. You will receive a confirmation number when ready.

Enrolling by phone or in person

Call 1-800-MEDICARE (1-800-633-4227) Monday through Friday, 8 a.m. to 8 p.m. Eastern time. A representative will ask for your name, date of birth, and Social Security number to pull up your Medicare record. Tell them you want to enroll in Part D and have your medication list ready. The representative will read through available plans in your area and their costs for your specific drugs. This process takes 20 to 30 minutes because the representative reads details aloud rather than showing them on a screen.

To enroll in person, visit your local Social Security office. You can find the address and hours at ssa.gov or by calling 1-800-772-1213. Bring your Medicare card, your medication list, and your Social Security card or other photo ID. A staff member will help you compare plans using a computer terminal, just as you would online. In-person enrollment takes 30 to 45 minutes because staff walk through each step with you.

What happens after you enroll

You will receive a confirmation number by email (if you enrolled online) or by phone (if you enrolled by phone or in person). Write this number down and keep it. Within two weeks, your new insurance company will mail you a welcome packet with your member ID card, plan details, and a list of covered drugs. Do not throw away the welcome packet — you need the member ID card to fill prescriptions.

Your coverage starts on the first day of the month after you enroll, or January 1 if you enroll between November 1 and December 7. If you enroll on January 15, your coverage starts February 1. If you enroll on November 20, your coverage starts January 1. Call your pharmacy before your coverage date to confirm they accept your new plan, because some pharmacies drop plans from year to year.

If you realize you chose the wrong plan within 14 days of enrollment, you can switch to a different plan. Contact your new insurance company or call Medicare at 1-800-MEDICARE to request the change. After 14 days, you are locked into that plan until the next Annual Enrollment Period in October.

Late enrollment penalties and creditable coverage

If you do not enroll in Part D during your Initial Enrollment Period and you do not have creditable coverage from another source, Medicare charges you a permanent penalty. The penalty is roughly 1 percent of the national average Part D premium for each month you were without coverage. If the national average premium is $35 and you were uninsured for 12 months, your penalty would be about $4.20 per month for life.

You avoid the penalty if you have creditable coverage — meaning prescription drug coverage that is at least as good as Medicare Part D — from an employer, a union, TRICARE, the Veterans Health Administration, or a state Medicaid program. If you have creditable coverage, you can enroll in Part D later without penalty. When you do enroll, bring documentation of your creditable coverage, such as a letter from your employer's benefits office or your insurance card.

If you missed your Initial Enrollment Period and do not have creditable coverage, you can still enroll during the Annual Enrollment Period (October 15 to December 7), but the penalty will explore. There is no way to remove the penalty once it starts, so it is worth enrolling as soon as you realize you need Part D coverage.

Changing your Part D plan

You can change Part D plans once per year during the Annual Enrollment Period from October 15 to December 7. Your new coverage starts January 1. You do not need a reason to switch — you can change plans straightforward because your costs went up, your pharmacy changed, or you want to try a different insurance company.

To switch plans, go to Medicare.gov, call 1-800-MEDICARE, or visit your local Social Security office. Use the same process you used to enroll the first time: enter your medications, compare plans, and select a new one. If you do nothing during the Annual Enrollment Period, your current plan continues into the next year, even if the premium or formulary changes.

Frequently Asked Questions

Can I enroll in Part D if I am still working and have employer coverage?

Yes, but check whether your employer coverage is creditable first. If it is, you can wait to enroll in Part D without penalty. If it is not, enroll in Part D now to avoid the permanent penalty. Your employer's benefits office can tell you whether your coverage is creditable.

What if my medication is not on my plan's formulary?

Contact your insurance company and ask for an exception. Many plans will cover drugs not on the formulary if your doctor writes a letter explaining why you need that specific medication. The process takes one to two weeks. If the exception is denied, you can switch plans during the next Annual Enrollment Period.

Do I have to use a specific pharmacy?

No, but your copay may be different at different pharmacies. Most plans have a list of preferred pharmacies where your copay is lower. You can use any pharmacy in the plan's network, but you will pay more at non-preferred locations. Check your plan's pharmacy list before you fill a prescription.

What if I move to a different state?

You can change plans outside the Annual Enrollment Period if you move. Contact your insurance company or Medicare within 60 days of your move to request a plan change. You will need to choose a plan available in your new state, because Part D plans are state-specific.

Can I enroll in Part D online if I do not have a computer?

Yes. Call 1-800-MEDICARE or visit your local Social Security office, and staff will help you enroll using their computer. You do not need your own device to complete enrollment.