What is Medicare Supplement insurance (Medigap)?
Private insurance that fills the gaps in Original Medicare.
Medigap, officially Medicare Supplement Insurance, is sold by private insurance companies to help pay the costs Original Medicare leaves behind: deductibles, coinsurance and copayments. With the right plan, most of your Medicare-covered bills can be paid in full.
How it works
Medicare pays its share of a covered service first, then your Medigap policy pays its share of what's left. You can see any doctor or hospital in the US that accepts Medicare; there are no networks, except for Medicare SELECT policies, which use one in exchange for a lower premium.
You pay a monthly premium to the insurance company, on top of your Part B premium.
Standardized plans
In most states, Medigap policies are standardized into lettered plans: A, B, C, D, F, G, K, L, M and N. Every Plan G, for example, has the same basic benefits no matter which company sells it; companies differ in price, service and financial strength. Massachusetts, Minnesota and Wisconsin standardize their plans differently.
Plans C and F aren't available to people who became eligible for Medicare on or after January 1, 2020.
What Medigap doesn't do
- It doesn't work with Medicare Advantage. It's illegal to sell you one if you're in a Medicare Advantage plan, unless you're switching back.
- It doesn't include drug coverage. You'd add a separate Part D plan.
- It doesn't cover long-term custodial care, routine dental, vision or hearing aids.
- It covers one person. Spouses each need their own policy.
When to buy
The best time is your 6-month Medigap Open Enrollment Period, which starts the month you're 65 or older and have Part B. During it, insurers can't refuse you or charge more because of your health. Outside it, in most states they can, unless you have a guaranteed issue right.
Common questions
Standard Medigap policies don't. You can use any provider who accepts Medicare. Medicare SELECT policies use a network in exchange for lower premiums.
The benefits are the same. Premiums, pricing methods, rate increases and customer service differ, which is why comparing companies matters.
It depends on your state. Federal law doesn't require insurers to sell to people under 65, but many states do. See our state pages.
Want help with your own choices?
Every state runs a State Health Insurance Assistance Program (SHIP) with trained counselors who give free, unbiased Medicare help and do not sell plans. Find yours on our Medicare by state pages, or call Medicare at 1-800-MEDICARE (1-800-633-4227) (TTY 1-877-486-2048, 24 hours a day, 7 days a week).
Planning the rest of your coverage in retirement? We can help with life insurance later in life and final expense coverage.
Sources
- Choosing a Medigap Policy (March 2026), Centers for Medicare & Medicaid Services. Checked September 29, 2026.
- Compare Medigap plan benefits, Medicare.gov. Checked September 29, 2026.
- When can I buy Medigap?, Medicare.gov. Checked September 29, 2026.
General information about the federal Medicare program, not advice about your situation. Figures are for 2026 unless stated and change every year; last reviewed September 29, 2026. Quote My Policy is a private company. Not connected with or endorsed by the United States government or the federal Medicare program.
Quote My Policy does not sell Medicare plans on this site. For plan-specific help, contact Medicare at 1-800-MEDICARE (1-800-633-4227) (TTY 1-877-486-2048, 24 hours a day, 7 days a week) or your State Health Insurance Assistance Program.