When and how you can switch Medicare plans

You can change Medicare plans only during specific windows set by Medicare each year. The main window is Annual Enrollment Period (AEP), which runs October 15 through December 7. During this time, you can switch between Original Medicare and Medicare Advantage, move between different Advantage plans, or add or drop prescription drug coverage. Outside these dates, you cannot change plans unless you have a may have access to life event — such as losing employer coverage, moving to a new state, or becoming newly may be able to access for Medicaid.

The process itself is straightforward: you choose a new plan, your old coverage ends on December 31, and your new plan starts January 1. But the timing matters. If you miss the important date or wait until late November, you risk a gap in coverage or paying higher premiums later. Starting your search in September gives you time to compare plans without rushing.

Key Takeaways

  • Annual Enrollment Period runs October 15 through December 7 each year, and this is when most people change plans.
  • You can change plans outside this window only if you have a may have access to event like losing employer coverage or moving states.
  • Medicare.gov's plan comparison tool lets you see costs, coverage, and networks side by side for plans in your area.
  • Changes made by December 7 take effect January 1, but plans made after that date may not start until later in the year.
  • If you miss the important date and have no may have access to event, you are locked into your current plan until the next October.

Steps to change your plan during Annual Enrollment

Start by going to Medicare.gov and signing into your account with your username and password. If you do not have an account, create one using your Social Security number and date of birth. Once logged in, click "Change Plans" or "Enroll" depending on what you see on your dashboard.

The site will show you all plans available in your ZIP code. You can filter by plan type (Original Medicare, Medicare Advantage, or Prescription Drug Plan), monthly premium, deductible, and whether your doctors are in-network. Take time to compare at least three plans. Look at the total out-of-pocket cost for the year, not just the monthly premium — a plan with a higher premium might cost less overall if your doctors are in-network and your prescriptions are covered at a lower tier.

Once you have chosen a plan, click "Enroll" on that plan's page. Medicare will ask you to confirm your choice and review your coverage start date. You will receive a confirmation number by email and mail. Keep this number — you may need it if questions arise about your enrollment.

What to do if you have a may have access to life event

A may have access to event is a change in your life that lets you change plans outside Annual Enrollment. The most common ones are: losing health coverage through an employer or spouse's employer, moving to a different state, becoming newly may be able to access for Medicaid or Extra Help, or having a change in your Medicaid status. Turning 65 and becoming newly may be able to access for Medicare is also a may have access to event.

When a may have access to event happens, you have a limited window — usually 60 days from the date of the event — to change plans. You must report the event to Medicare to start the process. Call 1-800-MEDICARE (1-800-633-4227) and tell them what happened. They will verify the event and give you a Special Enrollment Period (SEP) that lets you change plans when ready. You do not have to wait until October.

Have your event documentation ready when you call: a letter from your employer saying coverage ended, a lease or utility bill showing your new address, or a Medicaid approval letter. Medicare may ask to see these documents, and having them on hand speeds up the process.

Comparing Original Medicare versus Medicare Advantage

Before you change plans, decide whether you want to stay with Original Medicare (Parts A and B) or switch to a Medicare Advantage plan (Part C). This choice shapes everything else. Original Medicare lets you see any doctor who accepts Medicare, but you pay a deductible and coinsurance for each service. Medicare Advantage plans have networks like HMOs or PPOs, lower out-of-pocket costs for many people, and often include prescription drug coverage and dental or vision benefits — but you must use in-network doctors except in emergencies.

If you are thinking about switching from Advantage to Original Medicare, know that you may not be able to buy a Medigap supplemental policy without undergoing medical underwriting, which can mean higher premiums or denial of coverage. If you are switching from Original Medicare to Advantage, you do not have this problem — Advantage plans must accept you during Annual Enrollment.

Use Medicare's plan comparison tool to run the numbers for your specific situation. Enter your doctors' names and your current prescriptions. The tool will show you which plans cover them and at what cost. This real data beats any general rule.

Understanding prescription drug coverage when you change plans

If you are on Original Medicare and do not have prescription drug coverage (Part D), changing your medical plan does not automatically add it. You must enroll in a separate Prescription Drug Plan (PDP) during Annual Enrollment or within 63 days of losing other drug coverage. If you miss this window and do not have creditable coverage elsewhere, you will pay a permanent penalty on top of your premium when you do enroll.

If you are switching Medicare Advantage plans, check whether your new plan covers your prescriptions at the same cost tier. Formularies — the list of covered drugs — change every year, and a drug that was covered under your old plan may not be covered under your new one, or it may be in a higher tier that costs more. Call the new plan's pharmacy line or use their website to check before you enroll.

If your current plan no longer covers a drug you need, or covers it at a much higher cost, you may be able to request an exception from the plan. But this takes time and is not may provide. It is better to catch this during your comparison and choose a plan that covers your drugs at an affordable tier.

Common mistakes to avoid when changing plans

The biggest mistake is waiting until December to compare plans. By then, you have only days to decide, and you may miss important details about coverage or networks. Start looking in September. The second mistake is comparing only the monthly premium. A plan with a $0 premium might have a $500 deductible and higher copays, making it more expensive overall than a plan with a $50 premium. Always look at total annual cost.

A third mistake is not checking whether your doctors are in-network before you enroll in a Medicare Advantage plan. Call your doctor's office or use the plan's provider search tool. If your main doctor is not in-network, you will either pay out-of-network rates or have to switch doctors. A fourth mistake is forgetting to disenroll from your old plan. Medicare usually does this automatically when your new plan starts, but confirm it in writing or by calling to avoid paying two premiums.

Finally, do not assume your prescriptions are covered just because they were covered last year. Drug formularies change annually. Check the new plan's formulary before you enroll, not after.

Where to get help comparing and changing plans

Medicare.gov is the official source and has a plan comparison tool that shows all available plans in your area with costs and coverage details. You can also call 1-800-MEDICARE to speak with a representative who can walk you through your options over the phone. The call is free and available 24 hours a day, seven days a week.

Your State Health Insurance information Program (SHIP) offers free, one-on-one counseling about Medicare plans. To find your state's SHIP, go to Medicare.gov or call 1-800-MEDICARE and ask for the number. SHIP counselors know local plans and can help you understand the differences. Some employers and unions also offer benefits counseling for retirees — check with your former employer's benefits office.

Be cautious of unsolicited calls or emails from people claiming to represent Medicare or offering to help you change plans. Medicare does not call you first. If someone calls you, hang up and call 1-800-MEDICARE yourself to verify.

Frequently Asked Questions

What happens if I miss the December 7 important date?

If you miss the important date and do not have a may have access to life event, you cannot change plans until the next October. You are locked into your current plan for the rest of the year. The only exception is if you have a may have access to event like losing employer coverage or moving states — then you can request a Special Enrollment Period and change plans when ready.

Can I change plans more than once during Annual Enrollment?

Yes. You can change plans as many times as you want between October 15 and December 7. Each change cancels the previous one. Only your final choice on December 7 takes effect on January 1. However, changing multiple times can be confusing — compare carefully the first time and make one final choice.

Do I have to change plans every year?

No. If your current plan still covers your doctors and prescriptions at a cost you can afford, you can stay with it. But plans change their networks and formularies every year, so it is worth reviewing your options annually during October and November to make sure nothing has changed.

What if my new plan does not start on January 1?

If you enroll after December 7, your new plan may not start until later in the year — sometimes as late as March. Medicare will tell you the start date when you enroll. Until then, your old plan remains active. Make sure you understand when your coverage switches so you do not accidentally use the wrong insurance card at the doctor.

Can I switch back to my old plan if I do not like my new one?

Only during the next Annual Enrollment Period in October, unless you have a may have access to event. If you realize within the first few days of January that you made a mistake, call 1-800-MEDICARE when ready — in rare cases, Medicare may allow you to cancel and switch back, but this is not may provide and must be done very quickly.