Updated August 2026 · Reviewed by the CoverageCo team
Yes, outside of specific windows you can be denied a Medigap policy. During your one-time six-month Medigap open enrollment period, acceptance is guaranteed regardless of health. Outside it, and outside a limited set of guaranteed-issue rights, most states allow insurers to review your health history and decline you.
Key takeaways
- Your Medigap open enrollment is six months, starting when you're 65+ and enrolled in Part B.
- Inside that window: no health questions, no denial, no surcharge.
- Outside it: medical underwriting applies in most states, and denial is possible.
- A few situations create guaranteed-issue rights, but they don't cover most circumstances.
The one window where acceptance is guaranteed
Your Medigap open enrollment period is a single six-month window that begins when you are both 65 or older and enrolled in Medicare Part B.
During it, you can buy any Medigap policy sold in your state, from any insurer offering it, regardless of your health. They can't ask health questions in a way that affects your acceptance, can't decline you, and can't charge you more because of a pre-existing condition.
It does not repeat. Once it closes, it's closed — and that's what makes it the most consequential deadline in Medicare that nobody puts on a calendar.
What happens after it closes
In most states, insurers may then medically underwrite you. That means reviewing your health history and deciding whether to offer coverage, at what price, or at all.
You can absolutely still apply, and plenty of healthy people are approved. But approval is no longer a right, and a diagnosis in the intervening years can change the answer.
A handful of states have their own rules that are more generous than the federal baseline — some allow annual windows or continuous guaranteed issue. Rules vary meaningfully, so it's worth checking your specific state rather than assuming.
Guaranteed-issue rights outside the main window
Certain situations create a right to buy specific Medigap policies without underwriting. Common triggers include:
- Your Medicare Advantage plan leaves your area or stops offering coverage.
- You move out of your plan's service area.
- Your employer or union coverage that supplemented Medicare ends.
- You joined an Advantage plan when first eligible and want to switch back within the first year — sometimes called a trial right.
- Your insurer misled you or failed to follow the rules.
Why this should shape your first Medicare decision
This is the practical consequence, and it's the reason this page exists.
If you choose Medicare Advantage when you're first eligible and let your Medigap window pass, you may not be able to switch to Medigap later — precisely when declining health makes you want its predictability most.
That doesn't make Advantage the wrong choice. Millions of people are well served by it. But the decision deserves to be made knowing the door behind you may close, rather than discovering it years later.
If you're in that first window now, this is the moment to think it through carefully, with someone who can lay out both paths.
Common questions
When is my Medigap open enrollment period?
It's a one-time six-month window that starts when you're 65 or older and enrolled in Part B. During it, any Medigap policy sold in your state must accept you regardless of health.
Can I be denied Medigap for a pre-existing condition?
Not during your Medigap open enrollment period or a guaranteed-issue situation. Outside those, most states allow insurers to medically underwrite you and decline coverage based on health history.
Can I switch Medigap plans later?
You can apply anytime, but outside guaranteed-issue situations most states let the insurer underwrite the application. Some states have more generous rules, including annual windows, so check your state.
What is a Medicare Advantage trial right?
If you joined a Medicare Advantage plan when first eligible for Medicare, you generally have a right within the first year to return to Original Medicare and buy certain Medigap policies without underwriting.