Last updated: October 8, 2026
Medicare Supplement Insurance, also called Medigap, is extra insurance sold by private companies. It helps pay some of your share of costs in Original Medicare, such as copayments, coinsurance, and deductibles. Some Medigap policies also cover emergency medical care when you travel outside the United States.
A Medigap policy is different from a Medicare Advantage plan. Medigap supplements Original Medicare (Part A and Part B). Medicare Advantage is another way to get your Medicare benefits.
Medigap policies are standardized. In most states they are named by letter: Plans A-D, F, G, and K-N. Policies with the same letter offer the same basic benefits no matter where you live or which company sells them, so price is the only difference between same-letter policies from different companies. Massachusetts, Minnesota, and Wisconsin standardize their policies in a different way. Compare Medigap plan benefits on Medicare.gov.
The best time is during your Medigap Open Enrollment Period. This six-month period starts the first month you have Medicare Part B and are 65 or older. During it, an insurance company cannot refuse to sell you any Medigap policy it offers or charge you more because of pre-existing health problems. It happens only once; it does not repeat every year like fall Medicare Open Enrollment.
After this period, you may not be able to buy a Medigap policy, or it may cost more. If you delay Part B because you have group health coverage based on current employment, your Medigap Open Enrollment Period does not start until your Part B begins. Federal law generally does not require companies to sell Medigap to people under 65, although some states do. Some states also offer additional enrollment rights.
Medigap policies generally do not cover:
Some types of insurance are not Medigap policies, including:
To drop a Medigap policy, contact your insurance company to cancel it. Think carefully before you do: you might not be able to get the same policy, or any Medigap policy, back later. Most Medigap policies do not cancel automatically when you join a Medicare Advantage plan.
Older policies with drug coverage: Medigap policies can no longer be sold with drug coverage, but if you have an older policy that includes it, you can keep it. Most Medigap drug coverage is not creditable prescription drug coverage. If you go 63 days or more in a row without Medicare drug coverage or other creditable prescription drug coverage, you may have to pay a Part D late enrollment penalty when you join a Medicare drug plan later. You cannot have drug coverage through both a Medigap policy and a Medicare drug plan. If you join a Medicare drug plan, tell your Medigap company so it can remove the drug coverage and adjust your premium.
Trying Medicare Advantage for the first time: If you drop a Medigap policy to join a Medicare Advantage plan for the first time, you have a single 12-month trial right period to get your Medigap policy back if the same company still sells it once you return to Original Medicare.
Switching to a different Medigap policy: A new Medigap policy comes with a 30-day free look period. Do not cancel your first policy until you have decided to keep the new one; you pay both premiums for any month you have both. Learn more about changing Medigap policies.
Find Medigap policies in your area, read Choosing a Medigap Policy, or read Medicare & You 2027, pages 79-82. Contact our office for help comparing Medigap policies available to you.
