You can change your Medigap plan during the annual open enrollment period from October 15 to December 7, 2024, for coverage starting January 1, 2025

The main window to switch Medicare Supplement (Medigap) plans for next year is the Annual Enrollment Period, which runs October 15 through December 7 each year. If you enroll or switch during this window, your new plan takes effect on January 1. This is the easiest time to change plans because you do not need a medical reason, and insurers cannot deny you or charge more based on your health.

Outside this window, you can still switch plans, but the rules are stricter. You must have a may have access to life event — such as losing employer coverage, moving to a new state, or turning 65 — or you must be in your first year with Medicare. Some states also allow switches during their own open enrollment periods. The key is knowing which window applies to you and acting before the important date passes.

Key Takeaways

  • The Annual Enrollment Period for 2025 coverage runs October 15 to December 7, 2024, and is the simplest time to switch plans without medical underwriting.
  • If you miss the annual window, you can still switch during a may have access to event such as losing group health coverage, moving states, or turning 65 within the past year.
  • Some states have their own Medigap open enrollment periods that may allow switches outside the federal window; check your state insurance commissioner's office for dates.
  • Switching plans during the annual period means your new coverage starts January 1; switching outside the window may have a different start date depending on when you enroll.
  • Your current insurer cannot stop you from switching during the annual period, even if you have pre-existing conditions or have filed claims.

The Annual Enrollment Period: October 15 to December 7

Every year, Medicare opens a window for Medigap holders to switch plans without restrictions. For 2025, that window is October 15 through December 7, 2024. During this period, you can move from one Medigap plan to another, or from Medigap to Medicare Advantage and back, regardless of your health status or claims history.

The main advantage of using the annual period is that insurers must accept you at standard rates. They cannot charge you more, exclude coverage for any condition, or deny you based on your medical history. This protection — called may provide issue — applies only during the annual window. If you wait until January 8, that protection is gone.

To switch during this period, contact your new insurer directly or work with a licensed insurance agent. You do not need to notify your current plan first, though it is a good idea to confirm your new plan's start date before your old one ends. Most insurers will coordinate the switch so there is no gap in coverage.

Switching Outside the Annual Period: may have access to Life Events

If you miss the October 15 to December 7 window, you can still switch Medigap plans if you have had a may have access to event within the past 60 days. The most common may have access to events are losing employer-sponsored health coverage, moving to a different state, or turning 65 and enrolling in Medicare for the first time.

Other may have access to events include losing Medicaid coverage, having your current Medigap plan discontinued in your area, or being enrolled in a Medicare Advantage plan and losing that coverage. Each state may recognize slightly different events, so check with your state insurance commissioner's office to confirm whether your situation qualifies.

When you switch based on a may have access to event, you typically have 60 days from the date of the event to enroll in a new plan. The start date of your new coverage depends on when you enroll and your insurer's rules — it may be the first of the month following your enrollment, or it may be when ready. Contact the insurer before enrolling to confirm the effective date.

Your First Year with Medicare: The Six-Month Window

If you enrolled in Medicare Part B within the past six months, you are in a special enrollment period that allows you to switch Medigap plans without waiting for the annual window. This window is called the Medigap Open Enrollment Period, and it lasts six months from the date you first enroll in Part B.

During this six-month window, you have may provide issue protection — meaning insurers cannot deny you or charge more based on health. This is true even if you have pre-existing conditions or have already filed claims. Once the six months ends, you lose this protection unless you may have access to for another special enrollment period.

If you are unsure when your six-month window began, check your Medicare card or the letter Medicare sent when you enrolled in Part B. The date on that letter is when your window started.

State-Specific Open Enrollment Periods

Some states have their own Medigap open enrollment periods that run at different times than the federal annual window. These state periods may allow you to switch plans outside the October 15 to December 7 window, though the rules and dates vary widely.

States with their own open enrollment periods include Connecticut, Florida, Georgia, Indiana, Kentucky, Louisiana, Maine, Mississippi, Missouri, Montana, Nevada, New Hampshire, New Mexico, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, and West Virginia. If you live in one of these states, contact your state insurance commissioner's office to learn the exact dates and rules.

Even if your state has its own period, the federal annual window (October 15 to December 7) always applies to you. You can use either the state period or the federal period, whichever works best for your situation.

What Happens If You Miss All important date

If you miss the annual enrollment period and do not have a may have access to event, you cannot switch Medigap plans until the next annual period arrives. During the months in between, you are locked into your current plan. Your insurer can still raise premiums, and you cannot move to a different plan even if a better option becomes available.

The only exception is if your current plan is discontinued in your area, which qualifies as a special enrollment event. If that happens, your insurer is required to notify you and offer you alternative plans. You then have a window to switch without medical underwriting.

To avoid being locked in, mark your calendar for October 15 each year. Even if you think you will not switch, having the option available means you can respond quickly if your circumstances change or if a better plan launches.

How to Switch Plans: The Basic Steps

Once you have confirmed that you are in an open enrollment period or have a may have access to event, the process is straightforward. First, compare the plans available to you using the Medicare Plan Finder tool on Medicare.gov, or contact insurers directly for their rates and coverage details. Medigap plans are standardized — a Plan G from one insurer covers the same benefits as a Plan G from another — so the main differences are price and customer service.

Next, contact your new insurer to enroll. You can do this by phone, online, or through a licensed insurance agent. Have your Medicare number and current plan information ready. Your new insurer will confirm the effective date of your coverage and explain what happens to your old plan.

You do not need to formally cancel your old plan; your new plan will take over on the effective date. However, if there is any gap between when your old plan ends and your new plan starts, contact your old insurer to confirm the end date. Most switches are coordinated so coverage continues without interruption.

Frequently Asked Questions

Can I switch plans if I have already filed claims this year?

Yes, during the annual enrollment period (October 15 to December 7) you can switch plans regardless of how many claims you have filed. Your new insurer cannot deny you or charge more based on your claims history. Outside the annual period, you can still switch if you have a may have access to event, but your new insurer may explore medical underwriting if you are outside your first year with Medicare.

What if I move to a different state in 2025?

Moving to a new state is a may have access to event that allows you to switch Medigap plans outside the annual window. You typically have 60 days from your move to enroll in a new plan. Contact your new state's insurance commissioner's office to confirm the important date and which plans are available in your area, since Medigap availability varies by state.

If I switch during the annual period, when does my new plan start?

If you enroll between October 15 and December 7, 2024, your new coverage almost always starts on January 1, 2025. Confirm the exact date with your new insurer when you enroll. If you switch outside the annual period, the start date depends on your insurer's rules and when you enroll — it may be the first of the following month or a different date.

Do I need to tell my current insurer I am switching?

You do not have to notify your current insurer, but it is a good idea to do so after your new plan is confirmed. This ensures there is no confusion about when your old coverage ends. Your new insurer will handle most of the coordination, but confirming the end date with your old insurer prevents accidental lapses.

Can my current insurer charge me a penalty for switching?

No. During the annual enrollment period, your current insurer cannot charge a penalty or fee for switching. Outside the annual period, if you have a may have access to event, your new insurer cannot penalize you either. Penalties for switching are not allowed under Medicare rules.