Medicare Supplement (Medigap)
What Is Medicare Supplement Insurance?
Medicare Supplement insurance, also called Medigap, is private insurance that helps pay some of the costs Original Medicare doesn’t, like copayments, coinsurance and deductibles.
How Medigap works
A Medigap policy works alongside Original Medicare (Parts A and B). Medicare pays its share of approved costs first, then your Medigap policy pays its share.
- You must have Medicare Part A and Part B.
- You can generally see any doctor or hospital in the U.S. that accepts Medicare.
- Medigap policies don’t include prescription drug coverage. You can add a stand-alone Part D plan.
- Medigap can’t be used with a Medicare Advantage plan.
Plans are standardized by letter
In most states, Medigap plans are identified by letters: A, B, C, D, F, G, K, L, M and N. A licensed insurance agent can go over plan details with you.
Plan C and Plan F: These plans aren’t available to people who became eligible for Medicare on or after January 1, 2020. If you were eligible before then, you may still be able to buy them.
“Plan C” isn’t “Part C”. Medigap Plan C is a supplement plan. Part C is Medicare Advantage, which is a different kind of coverage.
Massachusetts, Minnesota and Wisconsin standardize Medigap plans differently.
When to buy: your Medigap Open Enrollment Period
Your Medigap Open Enrollment Period lasts 6 months. It starts the first month you have Medicare Part B and are 65 or older. During this time, insurance companies generally can’t refuse to sell you a policy or charge you more because of your health.
After this period, you may be asked health questions and could be turned down or charged more, unless you have a guaranteed-issue right or your state has additional protections.
Medigap vs. Medicare Advantage
| Original Medicare + Medigap | Medicare Advantage | |
|---|---|---|
| Who provides coverage | Original Medicare, plus a private Medigap policy | A private plan that contracts with Medicare |
| Doctors and hospitals | Any provider that accepts Medicare | Often a network; rules vary by plan |
Reviewed October 2026. Medicare rules and costs change every year. For the latest official information, visit Medicare.gov or call 1-800-MEDICARE (TTY 1-877-486-2048).
How we’re paid
Our service is free to you. We may be paid by the insurance agencies and companies we work with. You never pay us a fee, and you’re never obligated to enroll.
We do not offer every plan available in your area. Currently we represent 17 organizations which offer 96,646 products in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options.
Questions about Medicare? Talk with a licensed agent.
Mon–Fri, 8 a.m.–6 p.m. ET · TTY: +1 877-486-2048