Medicare Advantage Open Enrollment Period: What You Can Change

The Medicare Advantage Open Enrollment Period runs from January 1 to March 31 every year. If you’re already in a Medicare Advantage plan, you can use it to make one change: join a different Medicare Advantage plan, or leave Medicare Advantage for Original Medicare and add a stand-alone drug plan if you want one. Your new coverage starts the first day of the month after your plan gets the request.

It’s a useful second chance if the plan you picked in the fall isn’t working out. But it has limits, and leaving Medicare Advantage can affect your Medigap options.

MA OEP 2027 at a glance

• Dates: January 1 – March 31, 2027
• Who can use it: People already enrolled in a Medicare Advantage plan, with or without drug coverage
• How many changes: One
• When the change starts: The first day of the month after the plan gets your request. For example, a request made in February takes effect March 1.

What you can and can’t do

You can	You can’t
Switch from one Medicare Advantage plan to another, with or without drug coverage	Switch from Original Medicare into a Medicare Advantage plan
Drop your Medicare Advantage plan and return to Original Medicare	Switch from one stand-alone Part D drug plan to another
Join a stand-alone Part D plan when you return to Original Medicare	Join a stand-alone drug plan if you already have Original Medicare
Make one change during the period	Make a second change before March 31

If you have Original Medicare and want to make a change, the Annual Enrollment Period or a Special Enrollment Period is usually the way to do it.

Changing your Medicare Advantage plan in January

Many people use this window because something about their plan didn’t match what they expected. A doctor you see often may not be in the network, or a prescription may cost more than you planned. If you want to change your Medicare Advantage plan in January, February or March, you generally just enroll in the new plan. Your old plan generally ends on its own when the new one starts.

Because you only get one change, check the new plan’s network, drug list and costs before you enroll.

How to switch to Original Medicare

If you’d rather leave Medicare Advantage, you can switch to Original Medicare during this period. Contact your plan or call 1-800-MEDICARE (TTY 1-877-486-2048) to ask how to disenroll. If you join a stand-alone Part D plan at the same time, joining it generally ends your Medicare Advantage enrollment automatically.

Think about drug coverage before you leave. Original Medicare doesn’t cover most prescriptions you fill at a pharmacy, so most people add a stand-alone Part D plan. Under Medicare’s rules, if you go 63 days or more in a row without Part D or other creditable drug coverage, you may owe a late enrollment penalty for as long as you have Part D.

The Medigap question

This is the part people often miss. Original Medicare doesn’t pay all of your costs, so many people pair it with a Medicare Supplement (Medigap) policy. Your easiest chance to buy one is your 6-month Medigap open enrollment period, which starts the month you’re 65 and enrolled in Part B. During that window, there are no medical questions.

Outside that window, a Medigap insurer can generally ask about your health, and may decline to sell you a policy or charge you more. Federal and California rules give some people a right to buy a Medigap policy without medical questions in specific situations, so find out whether one applies to you before you drop your plan.

California adds another protection, but it works differently than people expect. If you already have a Medigap policy, California gives you an annual window of at least 60 days beginning on your birthday to switch to another Medigap plan with equal or lesser benefits without medical questions. The California Department of Insurance has the exact dates. Because this window is for moving from one Medigap policy to another, it usually won’t help if you’re coming from Medicare Advantage without one.

Before you leave Medicare Advantage, you can talk it through with HICAP, California’s Health Insurance Counseling & Advocacy Program (1-800-434-0222), which offers counseling at no charge. Our comparison of Medicare Advantage and Medigap in California goes deeper.

How the Medicare Advantage Open Enrollment Period differs from Annual Enrollment

The two windows are easy to mix up. Here’s how they compare:

	Annual Enrollment Period	MA Open Enrollment Period
Dates	October 15 – December 7	January 1 – March 31
Who can use it	Anyone with Medicare	Only people in a Medicare Advantage plan
Move from Original Medicare to Medicare Advantage	Yes	No
Switch stand-alone drug plans	Yes	No
When changes start	January 1	First day of the month after your request

In short, the fall window is for everyone and covers almost any change. The January–March window is a narrower follow-up for people already in Medicare Advantage. See our Annual Enrollment 2027 guide for the fall dates and choices.

Checklist before you switch

Before you use the Medicare Advantage Open Enrollment Period, work through these steps:

1. List your doctors, hospitals and pharmacies. Check that they’re in the new plan’s network, or that they accept Original Medicare.
2. List your prescriptions. Check each one on the new plan’s drug list, or on the drug list of the stand-alone Part D plan you’d join.
3. Compare total costs. Look at premiums, deductibles, copays and each plan’s yearly out-of-pocket maximum. You still pay your Part B premium either way.
4. If you’re heading to Original Medicare, look into Medigap first. Find out whether an insurer will sell you a policy, and at what price, before you leave your plan.
5. Line up drug coverage so you don’t have a gap.
6. Mind the deadline. Your request needs to reach the plan by March 31, and you get only one change.
7. Get help if you need it. The Medicare.gov plan finder, 1-800-MEDICARE, HICAP or a licensed agent can walk you through your options.

Frequently asked questions

Can I switch from Original Medicare to Medicare Advantage in January?

No. The January–March window is only for people already in a Medicare Advantage plan. If you have Original Medicare, you can join a Medicare Advantage plan during the Annual Enrollment Period (October 15 – December 7) or if you qualify for a Special Enrollment Period.

How many changes can I make between January 1 and March 31?

One. After your change takes effect, you can’t use this window again that year. Check networks and drug lists before you decide.

When does my new coverage start if I switch in February?

Your change takes effect the first day of the month after the plan gets your request. A request made in February would generally start March 1.

Can I change my stand-alone Part D plan during this period?

Not if you have Original Medicare. You can join a stand-alone drug plan in this window only if you’re leaving a Medicare Advantage plan for Original Medicare.

Is this the same as the old Medicare Advantage disenrollment period?

It replaced it. Until 2018, a Medicare Advantage disenrollment period from January 1 to February 14 only let you leave Medicare Advantage for Original Medicare. Since 2019, the Medicare Advantage Open Enrollment Period runs to March 31 and also lets you switch to another Medicare Advantage plan.

I just joined Medicare Advantage for the first time. Do other rules apply?

If you’re new to Medicare Advantage, you may also have a one-time chance to change during the first 3 months of your Medicare Advantage enrollment. Ask your plan or call 1-800-MEDICARE to confirm which window applies to you.

Talk with a licensed Boomers agent

A licensed Boomers agent can go over the Medicare plans we represent in your area and check them against your doctors and prescriptions before you decide whether to make a change. Our help is at no cost to you.

Find a licensed agent near you · See upcoming Medicare events

Or call 1-800-815-1943 (TTY 711), Monday – Friday, 9 AM – 5 PM Pacific.

Sources

• Joining a plan: enrollment periods (Medicare.gov)
• Medicare & You 2027 handbook (Medicare.gov)
• Medicare Supplement Insurance (Medigap) (Medicare.gov)
• Costs for Medicare drug coverage (Medicare.gov)
• Medicare Supplement Insurance “Medigap” senior advisory (California Department of Insurance)
• Medicare counseling: HICAP (California Department of Aging)