Medigap and Medicare Advantage: why you pick one, not both
They're for two different paths. Medigap only helps pay your costs under Original Medicare, so it can't be used with a Medicare Advantage plan. In most cases, a company can't sell you Medigap while you're in Medicare Advantage.
What matters most
They belong to different paths
A Medicare Advantage plan is another way to get your Medicare coverage besides Original Medicare. A Medigap policy only helps pay for the costs that Original Medicare doesn't cover.
Medigap can't pay Advantage costs
You can't use Medigap to pay your Medicare Advantage plan's copayments, deductibles, and premiums. With a Medicare Advantage plan, you can't buy Medigap to cover your out-of-pocket costs.
You usually can't be sold both
Insurance companies generally can't sell you a Medigap policy if you have coverage through a Medicare Advantage plan, unless you're switching back to Original Medicare.
Want the detail? How it works, a worked example and common mix-ups are in .
Words on this page
Medigap
extra insurance that helps pay your share of costs under Original Medicare
Medicare Advantage (Part C)
a private plan that is another way to get your Medicare, instead of Original Medicare
Supplement
to help pay part of the costs Original Medicare leaves to you
Who can answer for your situation
If you're weighing Medigap against a Medicare Advantage plan, a State Health Insurance Assistance Program (SHIP) counselor can walk through it with you for free, or call Medicare at 1-800-MEDICARE (1-800-633-4227).
Advantage plans usually include Part D; with Medigap you add a separate Part D plan.
Why they don't mix
Medigap is built to fill the gaps in Original Medicare. A Medicare Advantage plan is a different way to get your Medicare. So while you have a Medicare Advantage plan, a Medigap policy would no longer provide benefits that supplement Medicare.
An example
Say you already have a Medigap policy and then join a Medicare Advantage plan. You're allowed to keep the Medigap policy, but it would no longer add benefits while you're in the Advantage plan. You may want to drop it, since you'd be paying for coverage you can't use.
If you switch back to Original Medicare
If you have a Medicare Advantage plan but plan to return to Original Medicare, you can apply for a Medigap policy before your Medicare Advantage coverage ends.
Common mix-ups
These are the pairs people most often mix up.
Can I have both?
You can technically keep an old Medigap policy after joining Medicare Advantage, but it won't add benefits while you're in the plan. That's why people treat it as an either/or choice.
Dropping Medigap can be hard to undo
In most cases, if you drop your Medigap policy to join a Medicare Advantage plan, you may not be able to get the same policy back later.
1 What the source says · Section 2: Medigap basics, What's a Medigap policy?
A Medicare Advantage Plan is another way to get your Medicare coverage besides Original Medicare, while a Medigap policy only helps pay for the costs that Original Medicare doesn't cover.
Checked September 24, 2026
3 What the source says · Section 2: Medigap basics
Insurance companies generally can't sell you a Medigap policy if you have coverage through a Medicare Advantage Plan or Medicaid.
Checked September 24, 2026
4 What the source says · Section 5, What happens to my Medigap policy if I join a Medicare Advantage Plan?
You always have a legal right to keep the Medigap policy after you join a Medicare Advantage Plan. However, because you have a Medicare Advantage Plan, the Medigap policy would no longer provide benefits that supplement Medicare.
Checked September 24, 2026
5 What the source says · Section 5, What happens to my Medigap policy if I join a Medicare Advantage Plan?
You may want to drop your Medigap policy because you'll be paying for coverage you can't use.
Checked September 24, 2026
6 What the source says · Section 5, Medigap policies and Medicare drug coverage (Part D)
if you drop your Medigap policy to join a Medicare Advantage Plan, you may not be able to get the same policy back (or in some cases any Medigap policy), so pay careful attention to the timing.
Checked September 24, 2026
7 What the source says · Section 2: Medigap basics
If you have a Medicare Advantage Plan but plan to return to Original Medicare, you can apply for a Medigap policy before your Medicare Advantage coverage ends.
Checked September 24, 2026
9 What the source says · Section 4, Watch out for illegal practices (It's illegal if someone tries to sell you a Medigap policy if they know:)
You're in a Medicare Advantage Plan, unless you're switching back to Original Medicare.
General education, not individualized advice. For your own situation, you can call 1-800-MEDICARE or your State Health Insurance Assistance Program (SHIP).
Benny
Reading this page with you
Hi, I’m Benny. I can help you find the right guide and see how things connect.
I don’t write answers of my own yet. For now I’ll point you to the guides that match, and each one shows its sources.
I can help with
What I know about you
Nothing. On these public pages I don’t use any personal details, so everyone sees the same guides.
