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. In 2024, that window is October 15 through December 7. During these 53 days, you can switch from Original Medicare to a Medicare Advantage plan, move between Medicare Advantage plans, add or drop prescription drug coverage, or switch back to Original Medicare. Changes you make during Open Enrollment take effect on January 1 of the following year.

If you miss this window, you generally cannot change your coverage until the next Open Enrollment period — unless you have a may have access to life event like losing employer coverage, moving to a new state, or getting married. Missing the important date can lock you into a plan that no longer fits your needs or budget for a full year.

Key Takeaways

  • Open Enrollment for 2024 runs October 15 through December 7, and any changes take effect January 1, 2025.
  • You can switch between Medicare Advantage plans, add or remove prescription drug coverage, or return to Original Medicare during this period.
  • Medicare.gov, your plan's website, and 1-800-MEDICARE all have current plan options and costs for your area.
  • If you miss Open Enrollment, you cannot change plans unless you have a may have access to life event like moving or losing coverage.
  • Comparing plans before October 15 helps you decide what to do when the window opens.

What you can and cannot change during Open Enrollment

During Open Enrollment, you have full freedom to change your prescription drug plan (Part D), your Medicare Advantage plan (Part C), or your supplemental insurance (Medigap). You can also drop coverage you no longer want. If you are on Original Medicare without drug coverage, you can add a Part D plan. If you are on a Medicare Advantage plan that includes drug coverage, you can switch to a different Advantage plan or go back to Original Medicare plus a separate Part D plan.

What you cannot change during Open Enrollment is your Original Medicare coverage itself (Parts A and B) — that is set when you first turn 65 or become may be able to access. You also cannot enroll in Medicare for the first time during Open Enrollment; that requires your Initial Enrollment Period, which is the seven months around your 65th birthday. If you missed that window, you may face a permanent penalty on your premiums.

How to compare plans before the window opens

Start comparing plans in September, before October 15 arrives. Go to Medicare.gov and use the Plan Finder tool. Enter your zip code, current medications, and preferred doctors and hospitals. The tool shows you every Medicare Advantage plan and Part D plan available in your area, along with monthly premiums, deductibles, copays, and which pharmacies and providers are in-network.

You can also call 1-800-MEDICARE (1-800-633-4227) and speak with a counselor who can walk you through your options. Many states also run State Health Insurance information Programs (SHIPs) that offer free, one-on-one counseling. To find your state's SHIP, visit shiptalk.org or call 1-877-839-2675. These counselors know your local plans and can answer questions about how each one works.

Write down the names and phone numbers of two or three plans you are considering. Check whether your current doctors and pharmacy are in-network, what your out-of-pocket costs would be, and whether the plan covers the drugs you take. This homework takes an hour or two but saves you from buyer's remorse in January.

The three ways to make changes during Open Enrollment

Online: Go to Medicare.gov, log into your account, and follow the prompts to make changes. You can review your choices before confirming. Changes are when ready, and you get a confirmation email.

By phone: Call 1-800-MEDICARE and speak with a representative. They can answer questions while you are on the line and process your changes over the phone. This takes 20 to 30 minutes.

Through your plan: Call the plan directly (the number is on your insurance card or their website) and ask to make changes. Some plans also let you change through their website or mobile app. If you switch to a different plan, you do not need to contact your old plan — the new plan handles the transition.

Whichever method you choose, make your changes by December 7. Changes submitted after that date will not take effect on January 1.

What happens after you make changes

Once you submit your changes, you will receive a confirmation letter from Medicare and from your new plan within two weeks. The letter shows your new coverage details, your member ID number, and your effective date (January 1, 2025). Keep this letter — you will need it when you see a doctor or fill a prescription starting January 1.

If you are switching from one Medicare Advantage plan to another, your old plan ends on December 31, 2024. If you are switching from Medicare Advantage back to Original Medicare, you can enroll in a Part D plan at the same time, and both take effect on January 1. If you do not enroll in Part D when you switch back to Original Medicare, you may face a late-enrollment penalty on your drug premiums later.

In late December, your new insurance card will arrive in the mail. If it does not arrive by December 20, call your new plan and ask them to send it again or provide a temporary member ID you can use at the doctor's office.

What to do if you miss the October 15 important date

If December 8 arrives and you have not made changes, you are locked into your current plan for 2025 — with one exception. You have a second chance if you have a may have access to life event. These include losing employer coverage, moving to a different state, getting married or divorced, having a baby or adopting a child, or experiencing a significant drop in income. You have 60 days from the date of the event to make changes.

To report a may have access to event, call 1-800-MEDICARE or go to Medicare.gov and select "Report a Life Event." You will need to provide proof of the event — a letter from your employer, a lease showing your new address, a marriage certificate, or a tax return showing lower income. Once Medicare confirms the event, you get a Special Enrollment Period, usually lasting two months, to change your coverage.

If you do not have a may have access to event and you miss Open Enrollment, your only option is to wait until the next Open Enrollment period in October 2025. Plan ahead so this does not happen to you.

Common mistakes to avoid during Open Enrollment

Do not wait until December 6 to make changes. The website and phone lines get very busy in the final week, and if you have questions, you may not reach someone in time. Make your changes by mid-November so you have time to fix any errors.

Do not assume your current plan is still the best choice. Plans change their premiums, deductibles, and networks every year. A plan that was affordable in 2024 might cost much more in 2025, or your doctor might no longer be in-network. Spend 30 minutes comparing your current plan to one or two alternatives.

Do not forget to check whether your medications are covered under the new plan's formulary (drug list) and at what cost. A plan with a low premium might have high copays for your specific drugs, making it more expensive overall. Call the plan and ask, or use the Plan Finder tool to see the exact copay for each drug you take.

Do not switch plans just because a friend or family member recommends one. Their needs and doctors are different from yours. Use the Plan Finder tool to compare plans based on your own situation.

Frequently Asked Questions

Can I change my mind after I make changes during Open Enrollment?

Yes, but only if you change your mind before December 7. You can make as many changes as you want during Open Enrollment — each new change replaces the previous one. After December 7, you are locked in unless you have a may have access to life event. If you realize in January that you made a mistake, you will have to wait until October 2025 to change again.

What if my doctor or pharmacy is not in the new plan's network?

Call the plan and ask whether your doctor or pharmacy is in-network for 2025. If not, ask whether they offer an out-of-network option and what the copay would be. Some plans allow out-of-network care at a higher cost. If your doctor is not available in any plan in your area, you may need to find a new doctor or stay with your current plan.

Do I have to change plans every year?

No. If your current plan still works for you and the cost is acceptable, you can keep it. But it is worth comparing your plan to others each year because premiums and networks change. Many people find a plan that works and stick with it for years.

What if I turn 65 during Open Enrollment?

If you turn 65 between October 15 and December 7, you have your own Initial Enrollment Period, which is the seven months around your birthday month. You do not use Open Enrollment. Contact Social Security or Medicare to start your coverage, and they will explain your options.

Can I get help paying my Medicare premiums?

Yes. Programs like the Medicare Savings Program, Low-Income Subsidy, and Extra Help can reduce your premiums and out-of-pocket costs if your income is low enough. Contact your state Medicaid office or call 1-800-MEDICARE to learn whether you may be may be able to access and how the process works. These programs have their own enrollment periods and rules.