Medicare makes switching sound easy. Its open enrollment page lists the move right there in plain English: Between Oct. 15 and Dec. 7, you can leave a Medicare Advantage plan and go back to Original Medicare, with the change taking effect Jan. 1.
What that page doesn’t spell out is the catch. Leaving Medicare Advantage is the easy part. Getting a Medigap policy to go with Original Medicare is where people get stuck.
As the name implies, Medigap covers the “gap” of expenses not covered by Medicare. It’s a policy in addition to Medicare to help pay copayments and deductibles and lower out-of-pocket expenses.
In most states, outside a few protected situations, Medigap insurers are allowed to ask about your health, charge you more or turn you down.
Find that out after you’ve dropped your Medicare Advantage plan, and you can be left with Original Medicare and nothing to cover its gaps.
This isn’t a fringe problem. KFF, the health policy research group, estimated that 74% of Medicare Advantage enrollees — about 20.9 million people, based on 2023 data — have a medical condition that could get them denied.
I’ve been writing about money for more than 35 years, and few rules punish people for not knowing them quite like this one. Here are five things to understand before you make the switch.
1. Original Medicare alone is a gamble
Here’s the part a lot of people miss. Medicare Advantage plans cap your out-of-pocket spending on covered care each year. Original Medicare doesn’t. According to Medicare.gov, there’s no annual limit on your out-of-pocket costs unless you’ve added supplemental coverage or have other insurance.
Look at what that means in real dollars. In 2026, the Part A hospital deductible is $1,736 for each benefit period — not the year. Two hospital stays in separate benefit periods could mean $3,472 in deductibles before anything else.
Then there’s Part B, which covers doctor visits and outpatient care. After a $283 deductible, you usually pay 20% of the cost of each covered service. That 20% never stops.
Say you’re hit with $60,000 in outpatient treatment over a year, the kind of bill a serious illness can run up. Your 20% share would be about $12,000. Next year, it could happen again.
That’s why people leaving Medicare Advantage usually want a Medigap policy, which helps pay those costs. Without one, you’re self-insuring against the worst year of your life.
What to do: Don’t treat Medigap as an optional add-on. If you can’t get one, staying in a Medicare Advantage plan may be the safer move.
2. Medigap insurers can underwrite you
Outside of protected situations, buying Medigap works more like buying life insurance than buying Medicare. Insurers use something called medical underwriting.
According to Medicare.gov, an insurer can turn you down if your health doesn’t pass its underwriting screen, and approval can come at a higher price. The government’s Medigap guide adds that no company is obligated to sell you one.
In practice, as KFF Health News reported in March, that usually means a health questionnaire. More and more insurers also ask you to agree to a check of your prescription drug history, and an actuary told the outlet that your medication record may weigh more heavily than anything else.
And it may be getting harder. “Medigap insurers’ underwriting has tightened up considerably recently,” Bonnie Burns, a consultant with California Health Advocates, told KFF Health News.
Even if you’re approved, there may be strings attached. The government’s guide says an insurer can make you wait up to six months before it pays for costs tied to a preexisting condition.
What to do: Assume you’ll be underwritten unless you can confirm, in writing, that you have a guaranteed right to buy. Which brings us to the next point.
3. Your guaranteed rights — and their deadlines
Federal law gives you what Medicare calls guaranteed issue rights in certain situations. When one applies, the insurer has to sell you a policy, has to cover your preexisting conditions and can’t charge you more because of your health.
For people leaving Medicare Advantage, two situations matter most.
The trial right: If you joined a Medicare Advantage plan when you were first eligible for Medicare at 65 and you decide within your first year to go back to Original Medicare, you can buy any Medigap policy sold in your state.
A second trial right applies if you dropped Medigap to try Medicare Advantage for the first time and you’ve been in the plan less than a year. It lets you buy back the Medigap policy you had, or, if that one’s no longer sold, one of several standard plans.
Your plan is leaving: If your Medicare Advantage plan is pulling out of Medicare or stopping service in your area, or you move out of its service area, you get a guaranteed right too.
It isn’t rare. A JAMA study published in February estimated that about 1 in 10 people in individual (non-employer) Medicare Advantage plans would be forced out of their plans in 2026 because their plan exited their county.
This right comes with a shorter menu. Medicare lists Plans A, B, C, D, F, G, K and L, but C and F are off-limits if you became newly eligible for Medicare in 2020 or later. And it only works if you go to Original Medicare, not to another Medicare Advantage plan.
The deadlines are tight. According to the government’s guide, you can apply as early as 60 days before your Medicare Advantage coverage ends, and no more than 63 days after it ends.
If your plan sent you a non-renewal letter, I walked through that situation in detail in “Your Medicare Advantage Plan Won’t Be Back in 2027? A CPA on the Medigap Window That Protects You.”
Real talk — I’ve made plenty of money mistakes in my life, and I’ve spent decades helping people sidestep the ones they don’t have to make. Sign up for the free Money Talks Newsletter and let my scars save you a few of your own. Free, and worth more than that.
4. A few states protect you year-round — birthday rules won’t
Where you live can change everything.
A May 2026 chart from the National Association of Insurance Commissioners says New York and Massachusetts have continuous open enrollment for Medigap. KFF says Connecticut has continuous open enrollment as well, with guaranteed issue throughout the year. In those states, the scenario in this article mostly doesn’t apply.
Maine offers a narrower break. According to KFF, insurers there must sell at least Plan A during a one-month window each year, with each insurer picking the month. Plan A is a basic policy, but it’s coverage. KFF also says Maine stretches the federal one-year trial right to three years.
Now for the confusing part. You may have heard about the “birthday rule,” which KFF says exists in 16 states, including California, Illinois, Oregon and Virginia. It sounds like a yearly free pass. It isn’t one for you.
Those rules let people who already have a Medigap policy switch each year, around their birthday, to a different one with equal or lesser benefits.
KFF is explicit that they don’t let someone without Medigap buy a policy for the first time. If you’re coming from Medicare Advantage, you don’t have Medigap, so the birthday rule doesn’t help.
What to do: Check your own state’s rules before you assume anything. Some states go further than federal law, and Medicare.gov notes you may have extra rights under state law.
5. Get approved first, then switch
This is the single most important step, and it’s the one the “switching is easy” message skips.
You don’t have to leave Medicare Advantage to apply for Medigap. According to Medicare’s guide, if you’re planning to return to Original Medicare, you can apply for a Medigap policy while you’re still in your Medicare Advantage plan, and the insurer can sell it to you as long as you’re leaving.
The guide also says to ask that the new policy start when your Medicare Advantage enrollment ends, so your coverage doesn’t lapse. A Medigap policy can’t begin until your Medicare Advantage coverage is over anyway.
That turns a gamble into a decision. If you’re approved at a price you can live with, switch to Original Medicare by Dec. 7. If you’re turned down, or the premium is a shock, you’ve lost nothing. You can stay in Medicare Advantage.
Don’t forget drug coverage. If your Medicare Advantage plan included it, you’ll need to replace it. Medicare’s guide notes that with Original Medicare, you can join a separate drug plan to get Part D coverage.
Get free help: Before you do any of this, call your State Health Insurance Assistance Program, or SHIP.
It offers local, one-on-one Medicare counseling at no cost, and you can find your office at shiphelp.org. KFF Health News reported that SHIP counselors can point you to ways to get covered without underwriting.
The bottom line
The system is built so that leaving Medicare Advantage looks like a simple checkbox, while the hard part — whether an insurer will cover you — happens somewhere else, on someone else’s terms.
Flip the order. Find out whether you have a guaranteed right, check your state’s rules and apply for Medigap before you give up the plan you’ve got.
If you’re still weighing whether to stay, see “Your $0 Medicare Advantage Plan Just Got Worse. Check These 5 Things Before Dec. 7,” and keep track of every deadline with “7 Medicare Enrollment Windows Every Retiree Must Know.”
Add a Comment