Not as a right. Medicare’s Annual Enrollment Period (AEP), October 15 – December 7, is for changes to Medicare Advantage and Medicare drug plans — it doesn’t open a window to change a Medicare Supplement (Medigap) policy. You can apply for a different Medigap policy in any month, but unless you’re in your one-time Medigap Open Enrollment Period or have a guaranteed issue right, the insurer may use medical underwriting and can turn the application down.
Sourced from Medicare’s official guide Choosing a Medigap Policy (CMS), Medicare.gov’s switching Medigap policies page, and North Carolina’s Medicare Supplement law. Scope: this post is about changing from one Medigap policy to another while staying in Original Medicare.
- AEP (October 15 – December 7) covers Medicare Advantage and Medicare drug plans. It doesn't give you a right to switch Medigap policies.
- Under federal law, a right to switch Medigap generally comes from your one-time Medigap Open Enrollment Period or a guaranteed issue right. Outside those, an insurer may ask health questions and can say no.
- If you do switch, keep your current policy until you've decided to keep the new one. You have 30 days to decide, and you'll pay both premiums for the month you hold both.
Why AEP isn’t a Medigap window
The fall Medicare season brings a lot of mail, and it’s easy to read all of it as one big “change anything” window. It isn’t. AEP is when you can join, switch, or drop a Medicare Advantage plan or a Medicare drug plan, and move between Original Medicare and Medicare Advantage. Medigap policies run on their own rules.
Medicare’s guide puts it plainly: “In most cases, you won’t have a right under federal law to switch Medigap policies,” unless you’re within your six-month Medigap Open Enrollment Period or you’re eligible under a specific situation or guaranteed issue right. That Open Enrollment Period starts the first month you have Part B and are 65 or older, and it’s a one-time window that doesn’t repeat each year.
So picture someone who bought a Medigap policy at 65 and, years later, sees a neighbor talking about “switching during open enrollment.” They can apply for a different policy in October — or in March. The calendar doesn’t change the answer. What changes it is whether a guaranteed issue right applies.
When you do have a right to switch
Medicare’s guide notes that some states give people more opportunities to buy or switch than federal law does. North Carolina law doesn’t create a yearly switching window, so the federal list below is the place to start — and SHIIP (the NC Department of Insurance’s Seniors’ Health Insurance Information Program, 1-855-408-1212) can confirm whether any state rule adds to it for you. North Carolina law does give extra protections to people who have Medicare because of a disability before 65 (covered in our Medigap vs. supplemental insurance post): a six-month window to apply after they first enroll in Part B, and a separate right to buy certain Medigap plans within 63 days after their managed care coverage, such as a Medicare Advantage plan, ends. SHIIP can confirm which protection applies.
| Your situation | Do you have a right to buy? | When to apply (per Medicare’s guide) |
|---|---|---|
| You’re in your six-month Medigap Open Enrollment Period | Yes — any Medigap policy sold in your state, without medical underwriting | During the six months |
| Your Medicare Advantage plan leaves Medicare or stops serving your area, or you move outside its service area — and you return to Original Medicare | Yes — certain standardized Medigap plans | Confirm the application window for your situation with Medicare, including any instructions in your termination notice, before coverage ends |
| CMS determines that a significant Medicare Advantage network change qualifies you for a Special Enrollment Period, and you use that period to return to Original Medicare | Yes — certain standardized Medigap plans | Follow the notice for your Special Enrollment Period and confirm the separate Medigap application deadline with Medicare |
| You have Original Medicare and an employer or union group plan that pays after Medicare, and it’s ending | Yes — certain standardized Medigap plans | No more than 63 days after the latest of the dates Medicare lists |
| Your Medigap insurer goes bankrupt, or your coverage ends through no fault of your own | Yes — certain standardized Medigap plans | No more than 63 days after the policy ends |
| You joined Medicare Advantage when first eligible at 65 and return to Original Medicare within the first year, or you dropped Medigap to try Medicare Advantage for the first time and return within 12 months | Yes — available policies depend on the trial right; returning to your former Medigap policy may take priority | Confirm your trial-right eligibility, available policies, and application deadline with Medicare before leaving |
| None of these apply | You can apply, but the insurer may use medical underwriting and can decline | Any time |
That’s a summary, not the complete list — Medicare’s guide includes other situations, such as leaving a plan that didn’t follow the rules or misled you. A guaranteed issue right also usually means a right to certain standardized plans, not necessarily every policy on the market. If you think one of these applies, check the exact deadline before your current coverage ends.
How to switch without leaving a gap
When someone does switch — through a guaranteed issue right or because a new insurer accepts the application — the order of steps matters.
According to Medicare’s guide, you don’t cancel your first Medigap policy until you’ve decided to keep the second one. On the new application you’ll promise to cancel the first policy, and you have 30 days after you get the new policy to decide whether to keep it, paying both premiums for the month you have both. North Carolina adds its own protection: state law says a Medicare Supplement policy has to tell you that you can return it within 30 days of delivery and have the premium refunded if you’re not satisfied.
Waiting periods can follow a switch
If you buy under a guaranteed issue right, the insurer cannot exclude your pre-existing conditions. Otherwise, a new Medigap policy can sometimes delay coverage for a pre-existing condition. Per Medicare’s guide, if you’ve had your current Medigap policy for less than six months, the new policy may make you wait up to six months to cover a pre-existing condition, minus the months of prior coverage you already had. If a six-month waiting period otherwise applies and you have two months of qualifying prior coverage, that credit reduces the remaining wait to four months.
If the new insurer agrees to issue the replacement policy and your current policy has been in effect for at least six months, it cannot impose a new waiting period for similar benefits. But if the new policy includes a benefit your current one doesn’t, you may wait up to six months for that benefit regardless of how long you’ve been covered.
If AEP has you thinking about leaving Medicare Advantage
AEP does let you move from Medicare Advantage back to Original Medicare. The catch is the Medigap piece: in many situations there’s no guaranteed right to buy a Medigap policy afterward, and medical underwriting can apply. Check whether a guaranteed issue right or trial right covers you before you make that change, not after. Our post on changing your Medicare plan walks through those windows, including the separate Medicare Advantage Open Enrollment Period, which generally runs January 1 – March 31 for people already enrolled in Medicare Advantage (a separate three-month window may apply to people who joined a Medicare Advantage plan during their Initial Enrollment Period).
What AEP still means if you have Medigap
AEP isn’t irrelevant to a Medigap holder. Medigap policies sold after 2005 don’t include prescription drug coverage, and Medicare’s guide points people who want drug coverage to a separate Medicare drug plan. If that’s how you get yours, that plan can be changed during AEP. Our annual Part D check and the AEP checklist cover what’s worth reviewing before December 7.
If you’re weighing whether a Medigap change is possible in your situation, or how it fits with your drug coverage, I’m glad to walk through it with you. I work with multiple carriers, and you can book a time here or see the broader picture on our Medicare page.
(This is program-level educational information about Medicare and Medigap rules, not a comparison of specific plans, carriers, benefits, or premiums.)
