You can change your Medicare plan during specific windows each year, but the timing and your options depend on which type of plan you have and what triggered the change.

Medicare sets three main periods when you can switch plans without waiting until the next year. Outside those windows, you can only change if you experience a may have access to life event — a move, loss of coverage, or change in income. The rules differ sharply between Original Medicare (Parts A and B) and Medicare Advantage or Part D prescription drug plans, so the first step is knowing which one you currently have.

Most people can make changes during the Annual Enrollment Period, which runs October 15 to December 7 each year. Changes take effect January 1. If you miss that window, you may still have options depending on your situation, but they are narrower and have shorter important date.

Key Takeaways

  • The Annual Enrollment Period (October 15 to December 7) is when almost anyone can change Medicare plans, with changes taking effect January 1.
  • If you have Original Medicare with a Medigap or Part D plan, you can switch Medigap or Part D separately from Original Medicare itself.
  • Medicare Advantage plans have their own enrollment period (January 1 to March 31) when you can switch to a different Advantage plan or return to Original Medicare.
  • may have access to events like moving, losing coverage, or a major change in income can open a Special Enrollment Period outside the regular windows.
  • You must act within 60 days of a may have access to event, or you may lose the chance to change until the next Annual Enrollment Period.

The Annual Enrollment Period: October 15 to December 7

This is the main window when you can change any Medicare plan. It applies to Original Medicare, Medicare Advantage, Part D prescription drug plans, and Medigap supplemental insurance. You can switch from one plan to another, drop coverage, or add coverage you did not have before. The change takes effect on January 1 of the following year.

To make a change during this period, contact the plan you want to join directly — by phone, online, or in person at a local office. You do not have to contact your current plan to leave; the new plan handles the switch. However, you should confirm with your current plan that coverage ends on December 31 to avoid overlap or gaps.

This window is the most forgiving because you do not need a reason to change. You can switch straightforward because you want different coverage, a lower premium, or a different pharmacy network. No may have access to event is required.

Medicare Advantage Open Enrollment: January 1 to March 31

If you are already enrolled in a Medicare Advantage plan, you have a second chance to change plans during the first three months of the calendar year. During this period, you can switch to a different Medicare Advantage plan or go back to Original Medicare with Part D and Medigap. This window exists only for people already in Advantage plans — if you are in Original Medicare, you cannot use this period to switch into an Advantage plan.

Changes made during this period take effect on the first day of the month after you enroll. If you enroll on January 15, your new coverage starts February 1. This matters if you are trying to time a switch around a prescription refill or a doctor visit.

You can only use this window once per year, so if you switch plans in January, you cannot switch again until October 15. Plan carefully if you are considering multiple changes.

Special Enrollment Periods: When Life Changes Open a Window

If you experience certain life events, you may open a Special Enrollment Period that lets you change plans outside the regular windows. These events include moving to a new state or county, losing employer or union coverage, becoming may be able to access for Medicaid or Extra Help, getting married or divorced, or a significant change in your income or health status. The key is that the event must be recent — generally within the last 60 days.

Once a may have access to event occurs, you have 60 days to make a change. This important date is strict. If you wait 61 days, you lose the right to change until the next Annual Enrollment Period. Contact Medicare at 1-800-MEDICARE or your plan directly to report the event and ask what documentation they need.

Different events have different rules about which plans you can switch to. A move, for example, may open access to plans not available in your old location. Losing employer coverage lets you switch to any plan. Medicaid may be able to access may restrict your options. Ask Medicare or your plan which changes are available to you before you decide.

Switching Between Original Medicare and Medicare Advantage

Original Medicare (Parts A and B) and Medicare Advantage are two different ways to get coverage, and the rules for switching between them are not symmetrical. During the Annual Enrollment Period, you can move from Original Medicare to Advantage, or from Advantage back to Original Medicare. During the Advantage Open Enrollment Period (January 1 to March 31), you can only switch if you are already in Advantage — you cannot use this window to enter Advantage from Original Medicare.

If you switch from Original Medicare to Advantage, your Medigap coverage ends automatically. You do not need to cancel it, but you should confirm the end date with your Medigap insurer. If you later switch back to Original Medicare, you may have the right to re-enroll in Medigap without underwriting, but only if you act within 63 days of losing Advantage coverage. This is called Medigap Open Enrollment, and it is a one-time right per switch.

Switching from Advantage to Original Medicare also means your Advantage prescription drug coverage ends. You will need to enroll in a standalone Part D plan during the same enrollment period, or you will face a late enrollment penalty if you go without Part D and later want to join.

Changing Part D Prescription Drug Plans Without Changing Medicare

You can change your Part D plan independently of your Medicare coverage. If you are in Original Medicare with Part D, you can switch Part D plans during the Annual Enrollment Period without touching your Original Medicare coverage. If you are in Medicare Advantage with integrated drug coverage, you can switch to a different Advantage plan during the Advantage Open Enrollment Period, or switch to Original Medicare with a separate Part D plan during the Annual Enrollment Period.

Part D changes take effect January 1 if you enroll during the Annual Enrollment Period. If you miss that window and have a may have access to event — such as a significant increase in your drug costs or a change in which pharmacy you use — you may open a Special Enrollment Period. Contact your current Part D plan or Medicare to report the event within 60 days.

When comparing Part D plans, check whether your current medications are covered, what tier they are on (which determines your out-of-pocket cost), and whether your pharmacy is in the plan's network. Formularies and networks change every year, so a plan that worked last year may not work the same way this year.

What Happens If You Miss the Enrollment Windows

If you do not change your plan during an enrollment period and do not have a may have access to event, you are locked into your current plan until the next Annual Enrollment Period. You cannot switch, even if your premium goes up, your doctor leaves the network, or your medications are no longer covered at an affordable cost.

The exception is a Special Enrollment Period triggered by a life event. If you move, lose coverage, or experience another may have access to change, you have 60 days to act. After 60 days, the window closes. If you wait until November and realize you should have switched in September, you will have to wait until October 15 for the next Annual Enrollment Period.

Some people face a late enrollment penalty if they go without Part D or Medigap coverage for more than 63 days in a row. The penalty is added to your premium permanently, even after you enroll. This is why acting quickly during a Special Enrollment Period matters — it protects you from penalties.

How to Make the Change

Contact the plan you want to join, not the plan you are leaving. You can reach most plans by phone (the number is on your insurance card or plan documents), online through their website, or in person at a local office. Have your current Medicare card and any plan documents handy so you can answer questions about your coverage history.

The new plan will handle the paperwork and notify Medicare of the change. You do not need to call Medicare or your old plan to leave. However, you should keep records of when you enrolled and what coverage you selected, in case there are questions later.

After you enroll, the new plan will send you a confirmation letter and a new insurance card. This usually arrives within two weeks, but can take longer. Do not throw away your old card until you have the new one in hand and have confirmed the effective date of your new coverage.

Frequently Asked Questions

What if I enroll in a new plan but change my mind?

You have one chance to switch back during the same enrollment period. If you enrolled in a new plan during the Annual Enrollment Period and want to return to your old plan, you can do so before December 31, and the switch takes effect January 1. After January 1, you are locked in until the next enrollment period unless you have a may have access to event.

Can I change my plan if I move to a different state?

Yes, a move opens a Special Enrollment Period. You have 60 days from the date you move to change plans. Some plans may not be available in your new state, so contact Medicare or the plans you are interested in to confirm they operate in your new location. You will need to provide proof of your move, such as a lease or utility bill.

Do I lose coverage if I switch plans during an enrollment period?

No. Your old coverage stays in effect through December 31, and your new coverage begins January 1 (or the first of the month after you enroll during a Special Enrollment Period). There is no gap as long as you enroll before the important date. Confirm the end date with your old plan to be certain.

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

This is a common reason to switch plans, and it is allowed during any enrollment period. Before you enroll, check the new plan's provider directory to confirm your doctor is listed. If your doctor is not in any plan available to you, some plans allow out-of-network care at a higher cost. Ask the plan about this before you commit.

Can I change my Medigap plan without changing Medicare?

Yes. Medigap is separate from Original Medicare, so you can switch Medigap plans during the Annual Enrollment Period without changing your Medicare coverage. However, switching Medigap plans may require underwriting and health questions, depending on your age and how long you have had coverage. You have may provide issue rights (no underwriting) only in certain situations, such as within 63 days of losing other coverage.