1 in 10 Medicare Advantage members just lost their plan for 2026, but switching back has a catch

Just over half of all Medicare enrollees sign up for a Medicare Advantage plan over Original Medicare, meaning they choose a private insurance plan approved by Medicare over a government-administered insurance plan. Historically, either type of Medicare could work as part of a financially sound retirement plan.

However, a recent letter from Johns Hopkins researchers published in the Journal of the American Medical Association shows that 2.9 million Medicare Advantage enrollees are going to lose their plans in 2026 as insurers leave local markets.

If you're among the 10% of Medicare Advantage enrollees who will lose access to your plan, you probably know that you'll be automatically enrolled in Original Medicare Parts A and B when your plan expires. But you might not know about some key hang-ups related to Medigap coverage that can increase your healthcare cost burden unless you act quickly.

Keep reading to learn more about why you might want a Medigap policy when your Medicare Advantage plan expires, why underwriting makes it hard to secure Medigap policies, and how you can take advantage of an underwriting-free enrollment period once your plan ends.

What is Medigap?

Medigap, otherwise known as Medicare Supplement Insurance, is optional, extra insurance for Original Medicare beneficiaries. These policies, which are sold by private insurance companies, help you handle the out-of-pocket costs associated with Medicare, including deductibles, copays, and coinsurance costs.

Like Medicare Advantage plans. Medigap plans are specific to your region or state. You'll be automatically re-enrolled in your Medigap plan every year unless you fail to pay your premiums or the insurance company goes out of business or exits the market in your area. The automatic enrollment ensures you can't be removed from a policy because your health issues have worsened or you've been diagnosed with a new condition.

Can insurers deny your Medigap application?

While you can't be kicked off a Medigap plan once you have it, you may be denied a Medigap plan if you miss your enrollment period (more on that below). Outside of that time period, insurers can reject your application if they deem your preexisting medical conditions too risky or expensive. Alternatively, they can up your premiums or force you to wait six months before your coverage kicks in.

What are Guaranteed Issue Rights?

Individuals who opted for Original Medicare can sign up for a Medigap plan without being subject to underwriting in the six months after they turn 65 or sign up for Medicare Part B.

Since you were enrolled in Medicare Advantage, you don't qualify for the same open enrollment period, but losing Medicare Advantage coverage triggers Guaranteed Issue Rights, which means insurers must sell you a Medigap policy when you apply, with no medical underwriting required.

However, this window only stays open for 63 days after you lose your Medicare Advantage plan. If you miss that window, insurers in most states can require you to go through medical underwriting, which might lead to coverage denial or higher premiums.

Are medical underwriting laws for Medigap the same in every state?

While insurers in every state are required to respect the 63-day Guaranteed Issue Rights period, some states have additional protections that ensure you can purchase Medigap without constraints.

For instance, in Connecticut and New York, you can enroll in Medigap at any point sans medical underwriting. This means you can apply for Medigap outside of your 63-day window without financial consequences (beyond the potentially problematic gap in coverage). And in California and Oregon, a yearly open enrollment period for Medigap opens on your birthday and lasts 30 days. You can switch to any plan with the same benefits (or fewer) without medical underwriting.

Maine and Massachusetts also let beneficiaries switch Medigap plans once per year, and Washington, Illinois, Nevada, and Louisiana have Medigap options without medical underwriting in specific situations outside of the federally mandated Guaranteed Issue Rights period.

Are there different types of Medigap plans?

There are 10 different types of Medigap plans with benefits set by the federal government. For instance, all Medigap Plan G plans cover your Medicare Part A deductible, Part B excess charge, and 80% of costs associated with a medical emergency while traveling abroad, among other benefits.

How much does Medigap cost?

As with Medicare Advantage plans, Medigap policies differ in cost based on the insurance plan you choose, your age, and where you live. For instance, Medigap Plan G plans cost an average of $120 to $180 per month for 65-year-olds, $140 to $220 per month for 75-year-olds, and $170 to $250 per month for 85-year-olds.

Bottom line

If you've already been notified that your Medicare Advantage plan won't last past the new year, start looking into Medigap plans now so you're prepared to apply when your enrollment period opens.

Instead of contacting your old insurance company to ask about their Medigap policies and enrollment periods, contact your state's insurance department.

They can give you the best, most accurate information about which Medigap plans are available without medical underwriting, and they can let you know if your state has any extra laws that can help you save money in retirement instead of overspending on healthcare.