Medicare Open Enrollment runs from October 15 to December 7 each year

Open Enrollment is the yearly window when you can change your Medicare coverage without penalty. It happens the same time every year: October 15 through December 7. During these 53 days, you can switch between Original Medicare and Medicare Advantage plans, add or drop prescription drug coverage, or change which plan you're in. Any changes you make take effect on January 1 of the following year.

If you miss the October 15 start date, you can still enroll until December 7. However, once December 7 passes, you're locked into your current coverage for the entire next year — with rare exceptions. This is why marking your calendar in early October matters: the window closes, and you cannot change plans again until the following October.

Key Takeaways

  • Open Enrollment happens every year from October 15 to December 7, and any changes start on January 1.
  • You can switch from Original Medicare to Medicare Advantage, change prescription drug plans, or move between Advantage plans during this window.
  • Missing the December 7 important date means you cannot change your coverage until next October, with very few exceptions.
  • Medicare will mail you a notice in September or early October listing your current plan and the changes available to you.
  • You can review plans and make changes online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at a local Senior Center.

What you can change during Open Enrollment

Open Enrollment lets you make four main types of changes. First, you can switch from Original Medicare (Parts A and B) to a Medicare Advantage plan, or go the opposite direction — from Advantage back to Original Medicare. Second, you can change which Medicare Advantage plan you're in if you're already enrolled in one. Third, you can add prescription drug coverage (Part D) if you don't have it, or switch to a different Part D plan. Fourth, you can add or drop supplemental coverage (Medigap) if you have Original Medicare.

You cannot use Open Enrollment to change your Part A or Part B coverage itself — those are automatic once you turn 65 and enroll in Medicare. You also cannot change your Medigap plan to a different company during Open Enrollment; Medigap has its own separate enrollment rules. But for the four categories above, Open Enrollment is your main chance each year to make changes without medical underwriting or waiting periods.

How to find out what plans are available to you

In September or early October, Medicare mails you a notice called the "Annual Notice of Change" or "Important Notice About Your Medicare Prescription Drug Coverage." This notice lists your current plan, what the premiums and out-of-pocket costs will be next year, and whether your doctors and medications are still covered. Read this notice carefully — it tells you whether your plan is staying the same or changing.

You can also compare all plans available in your area by going to Medicare.gov and using the Plan Finder tool. Enter your ZIP code, the medications you take, and your preferred doctors and hospitals. The tool shows you every Original Medicare option, every Medicare Advantage plan, and every Part D plan available where you live, ranked by cost and coverage. You can also call 1-800-MEDICARE and speak to a representative who will walk you through your options over the phone.

When to make your decision and how to enroll

You do not have to wait until October 15 to start researching. Many people begin comparing plans in August or September, while the notice is still fresh. This gives you time to call your doctor's office to confirm they're in-network for any new plan you're considering, and to check whether your pharmacy carries your medications at the cost shown in the plan materials.

Once you've decided, you can enroll starting October 15. You have three ways to do it. Online: go to Medicare.gov, log in, and follow the enrollment steps — this usually takes 10 to 15 minutes. By phone: call 1-800-MEDICARE (1-800-633-4227) and a representative will enroll you over the phone. In person: visit your local Senior Center, Area Agency on Aging, or a certified counselor at a community health center who can help you enroll face-to-face. All three methods are free.

Whichever method you use, you'll receive a confirmation number. Write it down. Your new coverage starts January 1, and you should receive your new insurance card in the mail by December 20.

What happens if you miss the December 7 important date

If December 7 passes and you have not made a change, you stay in your current plan for the entire next year. You cannot switch plans again until the following October 15, even if your premiums go up, your doctor leaves the network, or your medication is no longer covered.

There are a few exceptions. If you experience a "may have access to life event" — such as losing employer coverage, moving to a new state, getting married, or having a significant drop in income — you may be able to change plans outside of Open Enrollment. You have 60 days from the date of the event to make a change. You'll need to report the event to Medicare and provide proof, such as a letter from your former employer or a copy of your marriage license. Call 1-800-MEDICARE to report a may have access to event and find out whether you can make a change.

Special rules if you're new to Medicare

If you're turning 65 or becoming may be able to access for Medicare for the first time, you have your own enrollment window called the Initial Enrollment Period. This is a seven-month window that starts three months before the month you turn 65 and ends three months after. During this time, you can enroll in any Medicare plan without waiting for October. Once your Initial Enrollment Period ends, you're bound by the Open Enrollment dates like everyone else.

If you miss your Initial Enrollment Period and do not enroll in Medicare when you first become may be able to access, you may face a permanent penalty on your premiums. The penalty is 10% of the Part B premium for each full year you could have had Part B but did not enroll. This penalty stays with you for life, even after you finally enroll. This is why it's important to enroll as soon as you're may be able to access, even if you're still working.

How to prepare before October 15

Start preparing in August or September. Gather a list of your current medications, including the dose and how often you take each one. Make a list of the doctors and specialists you see regularly, and note which hospital you prefer. If you have a chronic condition, write down the treatments or tests you expect to need in the coming year — this helps you understand whether a plan's out-of-pocket costs will be manageable for you.

Call your doctor's office and ask which Medicare plans they accept. Some doctors are in-network for Medicare Advantage plans but not others, and some only accept Original Medicare. If your doctor is not in-network for a plan you're considering, you may have to pay more or switch doctors. Ask now, before you enroll, so you're not surprised in January.

Review your current plan's Summary of Benefits and Coverage document — this is a plain-language guide to what your plan covers. Compare it to the same document for any new plan you're considering. Pay special attention to your out-of-pocket maximum, your deductible, and the copays for services you use most often.

Frequently Asked Questions

Can I change my mind after I enroll during Open Enrollment?

Yes, but only until December 7. If you enroll in a new plan on November 15 and then change your mind on November 20, you can switch to a different plan before the important date. However, once December 7 passes, your choice is locked in for the entire year. Make sure you're confident in your choice before the important date arrives.

What if my doctor or medication is no longer covered in my current plan next year?

This is a may have access to event that may let you change plans outside of Open Enrollment. Call 1-800-MEDICARE and explain the situation. You'll need to provide proof, such as a letter from your doctor's office or a notice from your pharmacy. Medicare will tell you whether you can make a change and how much time you have.

Do I have to do anything if I want to keep my current plan?

No. If you're happy with your current plan and want to stay in it, you don't have to do anything. Your coverage continues automatically on January 1. However, you should still read the Annual Notice of Change that Medicare sends you, because your premiums, deductibles, or covered services may change even if you stay in the same plan.

Can I enroll in a plan before October 15?

Not during Open Enrollment. However, if you're new to Medicare and within your Initial Enrollment Period, you can enroll any time during that seven-month window. If you've had a may have access to life event, you can also enroll outside of Open Enrollment. Otherwise, you must wait until October 15.

What if I'm still working and have coverage through my employer?

You can delay enrolling in Medicare without penalty if you have employer coverage and you're still actively working. However, once you retire or lose that coverage, you have a limited time to enroll in Medicare without facing a penalty. Talk to your employer's benefits office about your Medicare options and when you need to enroll.