When Medicare Open Enrollment Happens and What You Need to Know

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. During these eight weeks in the fall, you can switch between Original Medicare and Medicare Advantage plans, add or drop prescription drug coverage, or move to a different plan altogether. If you miss this window, you generally cannot make changes until the next year's Open Enrollment — unless a life event like losing employer coverage or moving to a new state gives you a Special Enrollment Period.

The dates are the same every year: October 15 through December 7. Your changes take effect on January 1 of the following year. This means if you enroll in a new plan on November 1, that plan starts covering you on January 1, not when ready.

Key Takeaways

Open Enrollment for Medicare happens every October 15 through December 7, and any changes you make take effect January 1.
You can switch between Original Medicare and Medicare Advantage, change prescription drug plans, or add dental and vision coverage during this window.
If you miss Open Enrollment, you cannot change plans until the next year unless a may have access to life event occurs, such as losing health coverage or moving.
Medicare sends notices to all beneficiaries before Open Enrollment begins, and you can compare plans on Medicare.gov or call 1-800-MEDICARE for help.

What you can change during Open Enrollment

During Open Enrollment, your options depend on what coverage you currently have. If you are on Original Medicare, you can switch to a Medicare Advantage plan (Part C), which bundles hospital, medical, and usually prescription drug coverage into one plan run by a private insurance company. If you are already on Medicare Advantage, you can switch back to Original Medicare, move to a different Medicare Advantage plan, or stay where you are.

For prescription drugs, you can add Part D coverage if you do not have it, drop it, or switch to a different Part D plan. You can also add or change supplemental coverage (Medigap) if you are on Original Medicare, though Medigap has its own enrollment rules outside of Open Enrollment. Dental, vision, and hearing coverage through Medicare Advantage plans can also be changed during this window.

Why the dates matter: planning ahead

The October 15 start date gives you time to review your current plan and compare new options before the December 7 important date. Many people wait until November or early December, which is fine, but comparing plans takes time — you will want to check whether your doctors are in-network, what your out-of-pocket costs will be, and whether your medications are covered at the price you expect.

Medicare sends you a notice called the "Annual Notice of Change" in September or early October. This notice tells you if your current plan's costs or coverage are changing. Read it carefully: sometimes your plan's premiums or deductibles go up, or a medication you take gets moved to a higher cost tier. That is often a sign you should compare other plans.

How to find out about plan changes and compare options

Start by visiting Medicare.gov and using the Plan Finder tool. You enter your current medications, doctors, and hospitals, and the tool shows you which plans cover them and what your costs would be. You can also call 1-800-MEDICARE (1-800-633-4227) and speak with someone who can walk you through your options. Both services are free and do not require you to enroll through them.

Many states also have State Health Insurance information Programs (SHIPs), which offer free one-on-one counseling about Medicare plans. Your local Area Agency on Aging can connect you to your state's SHIP. These counselors know your state's specific plans and can answer questions about how coverage works in your area.

What happens if you miss the important date

If December 7 passes and you have not made a change, your current plan continues into the new year without interruption. You cannot switch plans again until the next October 15, with one major exception: a Special Enrollment Period.

You may have access to for a Special Enrollment Period if you experience certain life events, such as losing employer health coverage, moving out of your plan's service area, getting married or divorced, or having a significant drop in income. You typically have 60 days from the event to make a change. If you think you may have access to, call 1-800-MEDICARE to report the event and find out whether you can change plans outside of Open Enrollment.

important date and timing for your new coverage

Any plan changes you make between October 15 and December 7 take effect on January 1. This means there is no gap in coverage — your old plan ends and your new plan begins on the same day. However, you should verify your new plan's coverage before January 1 arrives. Check that your doctors are confirmed in-network, that your pharmacy is listed, and that your medications are covered.

If you enroll in a plan and then change your mind, you have until December 31 to disenroll and go back to your previous coverage (or choose a different plan). After December 31, you are locked into your choice for the full year unless a Special Enrollment Period applies.

Preparing now for next year's Open Enrollment

If Open Enrollment is months away, you can still prepare. Keep a list of your current medications and their costs. Note which doctors and hospitals you use most often. If your plan changes its formulary (the list of covered drugs) or your doctor leaves the network, write down the date and the change — this information helps you decide whether to switch plans when Open Enrollment arrives.

Set a calendar reminder for mid-October so you do not forget the start date. If you have questions before Open Enrollment begins, you can call 1-800-MEDICARE anytime to learn how your current plan works or to ask general questions about Medicare coverage types.

Frequently Asked Questions

Can I change my Medicare plan outside of October 15 to December 7?

Only if you have a may have access to life event, such as losing employer coverage, moving, getting married or divorced, or experiencing a significant income change. You must report the event within 60 days to may have access to for a Special Enrollment Period. Call 1-800-MEDICARE to report the event and learn whether you can change plans.

What if my doctor leaves my plan's network after I enroll?

If your doctor leaves the network after you enroll, you may be able to request a Special Enrollment Period to switch plans outside of Open Enrollment. Contact your plan directly to report the change, and ask whether you may have access to to switch. If not, you can change plans during the next Open Enrollment.

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

No. If you do not make any changes during Open Enrollment, your current plan automatically continues into the new year. However, review your Annual Notice of Change to see if your costs or coverage are changing, so you know what to expect in January.

Where can I get help comparing plans if I am not comfortable using a computer?

Call 1-800-MEDICARE and speak with a representative who can compare plans for you over the phone. You can also contact your State Health Insurance information Program (SHIP) for free, one-on-one counseling. Your local Area Agency on Aging can give you your state's SHIP phone number.

What if I enroll in a new plan and then realize it was a mistake?

You have until December 31 to disenroll from a plan you chose during Open Enrollment and return to your previous coverage or select a different plan. After December 31, you are locked in for the full year unless a Special Enrollment Period applies.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.