Yes, you can switch from Medicare Advantage to Medigap, but timing and your health matter

You can move from a Medicare Advantage plan to a Medigap policy, but you cannot do it whenever you want. Medicare has specific windows when you are allowed to switch without being turned down for pre-existing conditions. If you miss these windows, an insurance company can deny you coverage or charge you more based on your health history. The most important window is the six months after you first enroll in Medicare Part B — during this time, Medigap insurers must sell you a policy at standard rates, no matter what your health is.

Outside of these protected periods, insurers can refuse to cover you or add extra charges. This is why understanding when you can switch, and acting during the right window, makes a real difference in your options and your costs.

Key Takeaways

  • You have a may provide right to buy Medigap during the six months after you first enroll in Medicare Part B, regardless of health conditions.
  • If you drop Medicare Advantage within the first 12 months of enrollment, you have a second window to buy Medigap without medical underwriting.
  • Outside these windows, Medigap companies can deny you coverage or charge higher premiums based on your medical history.
  • You must actively disenroll from Medicare Advantage and enroll in Original Medicare before you can buy a Medigap policy.
  • The timing of your switch affects your coverage dates, so plan ahead to avoid gaps in protection.

The two protected windows for switching to Medigap

The first protected window is the six months after you turn 65 and enroll in Medicare Part B for the first time. During this period, called the Medigap Open Enrollment Period, any insurance company must sell you any Medigap plan they offer at their lowest available rate. Your health history does not matter — they cannot turn you down or charge you more. This window closes six months after your Part B coverage starts, so if you enroll in Part B on January 1, your window closes on June 30.

The second protected window applies if you are already in a Medicare Advantage plan. If you drop that plan within the first 12 months of enrollment, you have 63 days from the date your Advantage plan ends to buy a Medigap policy without medical underwriting. This means the insurance company cannot ask about your health or deny you based on pre-existing conditions. After 63 days, this protection ends.

If you miss both windows, you lose these guarantees. Medigap companies can then require medical underwriting, which means they review your health history and can refuse to sell you a policy or charge you a higher premium.

What happens to your Medicare Advantage coverage when you switch

Switching from Medicare Advantage to Medigap is a two-step process. First, you must disenroll from your Medicare Advantage plan. Second, you must enroll in Original Medicare (Part A and Part B) if you are not already enrolled. Only after you are in Original Medicare can you buy a Medigap policy.

The timing of when you make these changes affects when your new coverage takes effect. If you disenroll from Medicare Advantage during the annual open enrollment period (October 15 to December 7), your new coverage usually starts on January 1. If you disenroll outside open enrollment but within a may have access to event window, your coverage start date depends on when you submit your request. You should contact Medicare or your current plan to confirm the exact date your Advantage coverage will end and when your new coverage will begin.

During the gap between when your Advantage plan ends and your Medigap coverage starts, you may have no coverage. This is why timing your switch carefully matters — you want your Medigap policy to start the same day your Advantage plan ends, or as close as possible.

When you cannot switch without medical underwriting

If you miss the protected windows, Medigap insurers can require you to answer health questions and can use your answers to decide whether to sell you a policy and at what price. Some companies will deny you outright if you have certain conditions. Others will sell you a policy but at a much higher rate than someone with no health issues would pay. A few companies may offer limited coverage that excludes your pre-existing conditions for the first six months.

The amount of extra cost varies by company and by your health history. There is no set rule — each insurer sets its own underwriting standards. This is why it is critical to switch during a protected window if you can. The difference in cost between may provide issue and medically underwritten rates can be hundreds of dollars per year.

How to make the switch step by step

Start by choosing a Medigap plan and an insurance company. You can compare plans on Medicare.gov or call 1-800-MEDICARE. Once you have chosen, contact the insurance company directly to begin enrollment. Do not wait — some companies have waiting lists during open enrollment.

At the same time, contact your current Medicare Advantage plan to disenroll. You can do this by phone, by mail, or through your plan's website. Tell them the date you want your coverage to end. If you are switching during the annual open enrollment period, your Advantage plan will end on December 31 and your new coverage will start on January 1. If you are switching for another reason (such as moving out of the plan's service area), the timing may be different.

After you disenroll from Medicare Advantage, Medicare will automatically re-enroll you in Original Medicare Part A and Part B if you are already enrolled in those parts. If you are not yet enrolled in Part B, you will need to enroll separately. Once your Original Medicare enrollment is confirmed, your Medigap policy can take effect.

Keep copies of all confirmation letters from your Medigap company, your Medicare Advantage plan, and Medicare itself. These documents prove your coverage dates and protect you if there are billing disputes later.

Costs and plan differences to consider before switching

Medigap policies cover some costs that Medicare Advantage plans do not, but they also cost more in monthly premiums. With Medigap, you pay a monthly premium to the Medigap company, and then you also pay Medicare's Part B premium. You also pay a Part A deductible and a Part B deductible, though some Medigap plans cover these deductibles. Medicare Advantage plans typically have lower monthly premiums but higher out-of-pocket costs when you use care, and they limit which doctors and hospitals you can see.

The trade-off is predictability versus flexibility. Medigap gives you more predictable costs and access to any doctor who accepts Medicare. Medicare Advantage limits your network but may cost less per month if you are healthy and do not use much care. Before you switch, compare the total cost of both options — not just the monthly premium, but also the deductibles, copays, and coinsurance you would pay under each plan.

What to ask your doctor and Medicare before you switch

Ask your current doctor whether they accept Medigap insurance and whether they accept the specific Medigap plan you are considering. Some doctors accept Medicare but not all Medigap plans. Ask whether any of your current medications or treatments require prior authorization or have coverage limits under Medigap. Ask whether you need any specialist referrals before you switch, because Medigap does not require referrals but your current Advantage plan might.

Call Medicare at 1-800-MEDICARE and confirm your Part A and Part B enrollment dates. Ask whether you are in your Medigap Open Enrollment Period or whether you have another protected window available. Ask what your exact coverage dates will be if you disenroll from your Advantage plan on a specific date. Get the name of the Medicare representative you spoke with and the date of the call, in case you need to refer back to that conversation later.

Frequently Asked Questions

What if I switch to Medigap and then want to go back to Medicare Advantage?

You can switch back to Medicare Advantage during the annual open enrollment period (October 15 to December 7) or if you have a may have access to life event. However, you do not have a may provide right to buy Medigap again if you leave it. If you want to return to Medigap later, you may face medical underwriting unless you are in a protected window.

Do I have to switch during open enrollment, or can I switch anytime?

You can switch anytime if you have a may have access to event, such as moving out of your plan's service area, losing employer coverage, or experiencing a change in your household. Outside of open enrollment and may have access to events, you can only switch if you are in a protected Medigap window. Contact Medicare to confirm whether your situation qualifies as a life event.

What if my Medigap company denies me coverage after I miss the protected windows?

If you are denied, ask the company in writing why you were denied and request information about their underwriting standards. Some states have laws that limit how much Medigap companies can charge based on health history. Contact your state's insurance commissioner's office to learn what protections explore in your state and whether you have a right to appeal the denial.

Can I buy Medigap while I am still in Medicare Advantage, or do I have to disenroll first?

You must disenroll from Medicare Advantage and be enrolled in Original Medicare before your Medigap policy can take effect. However, you can start the enrollment process with a Medigap company while you are still in Advantage — just make sure your Medigap coverage does not start until after your Advantage plan ends, to avoid paying for overlapping coverage.

Will switching to Medigap affect my prescription drug coverage?

Medicare Advantage plans include prescription drug coverage. When you switch to Original Medicare with Medigap, you need to enroll in a separate Part D prescription drug plan. You have 63 days from when your Advantage plan ends to enroll in Part D without a late enrollment penalty. If you miss this window, you may pay a higher premium for Part D for as long as you have it.