What is a Medicare Supplement (Medigap) plan?

Medigap is private insurance that pays some or all of the costs Original Medicare leaves you — deductibles, coinsurance, and the 20% under Part B. The plans are standardized by federal law into lettered versions (A through N), so a Plan G is the same coverage at every insurer; only the price and the company’s rating method differ. Medigap works only with Original Medicare, not Medicare Advantage.

Can you have Medigap and Medicare Advantage at the same time?

No. A Medigap policy only pays costs under Original Medicare. If you are enrolled in a Medicare Advantage plan, a Medigap policy cannot pay your share, and it is generally illegal for someone to sell you one. The real choice is Original Medicare plus Medigap versus Medicare Advantage.

Why were Medigap Plans C and F discontinued for some people?

Plans C and F covered the Part B deductible, and a 2015 federal law (MACRA) stopped new enrollees from buying plans that do so. Plans C and F are closed to people who became eligible for Medicare on or after January 1, 2020. People eligible before 2020 can still buy or keep them; everyone else gets Plan D or Plan G as the closest equivalents.

When can I buy Medigap without answering health questions?

During your one-time 6-month Medigap Open Enrollment Period, which starts the first month you are 65 or older and enrolled in Part B — you can buy any plan sold in your state with no medical underwriting. Certain events also create limited guaranteed-issue rights (generally 63 days), and some states add year-round or birthday-window protections. Outside those, an insurer can charge more or decline you based on health.

Medicare Supplement (Medigap) plans, explained

Plain-English summary: Medigap is private insurance that fills the gaps in Original Medicare — the deductibles, coinsurance, and the 20% Part B leaves you to pay, which Original Medicare caps at nothing on its own. The benefits are standardized by federal law into lettered plans (A through N), so a Plan G is the same coverage at every insurer; what differs is the price. Medigap works only with Original Medicare — not with Medicare Advantage. Reported, not recommended.

IndependentFederal (CMS / Medicare.gov) sourcesNo plan pays for placementNot Medicare, not an insurance agency

What Medigap is — and the rule people miss

Original Medicare (Part A and Part B) pays most of your hospital and doctor bills, but it has deductibles, coinsurance, and no annual out-of-pocket cap. A Medigap policy pays some or all of those remaining costs. Because the plans are standardized, the only things that vary between insurers for the same lettered plan are the premium, the company’s rating method, and a few extras.

Medigap and Medicare Advantage don’t mix. A Medigap policy only pays costs under Original Medicare. If you’re in a Medicare Advantage plan, a Medigap policy can’t pay your share, and it’s generally against the law for anyone to sell you one. So the real choice is usually Original Medicare + Medigap (+ a Part D drug plan) versus Medicare Advantage — see how the two compare.

The standardized plans, A–N

Every Medigap plan with the same letter covers the same benefits, by law, no matter which company sells it. (Massachusetts, Minnesota, and Wisconsin standardize their plans differently — see below.) Here is what each lettered plan covers:

Benefit	A	B	C	D	F	G	K	L	M	N
Part A coinsurance & hospital costs (up to 365 extra days)	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Part B coinsurance or copayment	✓	✓	✓	✓	✓	✓	50%	75%	✓	✓^†
Blood (first 3 pints)	✓	✓	✓	✓	✓	✓	50%	75%	✓	✓
Part A hospice care coinsurance or copayment	✓	✓	✓	✓	✓	✓	50%	75%	✓	✓
Skilled nursing facility care coinsurance	—	—	✓	✓	✓	✓	50%	75%	✓	✓
Part A deductible	—	✓	✓	✓	✓	✓	50%	75%	50%	✓
Part B deductible	—	—	✓	—	✓	—	—	—	—	—
Part B excess charges	—	—	—	—	✓	✓	—	—	—	—
Foreign travel emergency (up to plan limits)	—	—	80%	80%	80%	80%	—	—	80%	80%
Out-of-pocket yearly limit (2027)	—	—	—	—	—	—	$8,000	$4,000	—	—

✓ covered in full · 50% / 75% that share of the cost · 80% of foreign-travel emergency care, up to plan limits · — not covered · † Plan N pays Part B coinsurance in full except a copay of up to $20 for some office visits and up to $50 for an emergency-room visit that doesn’t lead to admission. After you reach the out-of-pocket limit and the Part B deductible ($283 in 2026), Plans K and L pay 100% for the rest of the year.

Plans C and F are closed to people new to Medicare on or after January 1, 2020. They were the only plans that covered the Part B deductible, and a 2015 federal law (MACRA) stopped that for new enrollees. If you were eligible for Medicare before 2020 you can still buy or keep C or F; everyone else gets Plan D or Plan G as the closest equivalents. “New to Medicare” means turning 65, or first becoming eligible through disability or ESRD, on or after January 1, 2020.

When you can buy without medical underwriting

Timing matters more with Medigap than almost anything else in Medicare, because outside certain windows an insurer can charge you more — or turn you down — for your health.

Your 6-month Medigap Open Enrollment Period. It starts the first month you’re 65 or older and enrolled in Part B. During it, you can buy any Medigap plan sold in your state at the best rate, with no health questions. It happens once and does not repeat each year — this is the single most important Medigap deadline.
Guaranteed-issue rights. Certain events give you a limited right (generally 63 days) to buy specific Medigap plans without underwriting — for example, if your Medicare Advantage plan leaves Medicare or your area, or if you try Medicare Advantage and switch back to Original Medicare within 12 months (a “trial right”).
Some states go further. A handful of states require guaranteed issue year-round or at an annual “birthday” window, and a few (such as New York and Connecticut) bar pricing by age or health. These rules change and vary a lot — confirm yours with your state and your SHIP.

How premiums are set — and why we don’t publish a price list

The same Plan G can cost very different amounts depending on the insurer and how it prices. There are three rating methods:

Community-rated: everyone pays the same premium regardless of age. Often the least expensive over a lifetime.
Issue-age-rated: based on your age when you buy; it doesn’t rise automatically as you get older (though the insurer can still raise rates for everyone).
Attained-age-rated: starts lower at 65 but rises automatically as you age.

Why there’s no premium table on this page. Unlike Medicare Advantage — where every plan’s benefits and premiums come from free CMS public-use files — Medigap premiums are set by private insurers and filed state by state. There is no free, authoritative national dataset of Medigap rates; structured rate data is sold only by commercial vendors. So rather than publish numbers we can’t stand behind, we send you to the official tools: Medicare’s own Medigap plan finder (enter your ZIP to see the plans and companies in your area), your state insurance department, and your free SHIP counselor. Treat any premium you see there as an estimate until you confirm it with the insurer.

A few special cases

High-deductible Plan F and Plan G. You pay a yearly deductible — $2,950 in 2026, rising to $3,050 in 2027 — before the policy pays, in exchange for a lower premium. High-deductible Plan F is only for people not new to Medicare before 2020; high-deductible Plan G is the version available to those new on or after that date.
Medicare SELECT is a Medigap policy that costs less because it uses a network of hospitals (and sometimes doctors). Federal law gives you 12 months to switch from a SELECT policy to a standard Medigap plan.
Under 65 and on Medicare. Federal law doesn’t require insurers to sell Medigap before age 65, and pricing for those who can buy varies; many states add their own protections, and rules for people with ESRD differ. Check your state.
Massachusetts, Minnesota, and Wisconsin don’t use the A–N letters — they standardize Medigap their own (CMS-approved) way, so the plan names and structures there look different.

How Medigap fits the bigger choice

Most people are really deciding between Original Medicare plus a Medigap policy and a Part D drug plan, which trades a monthly premium for broad provider choice and predictable costs, and Medicare Advantage, which usually costs less up front but uses a network and an out-of-pocket cap. We lay that out neutrally in Medicare Advantage vs. Original Medicare and the trade-offs people actually ask about. To see the Medicare Advantage plans filed where you live, use our county plan finder.

We report the federally standardized benefits and rules and link to official tools for prices; we do not sell insurance, quote or rank plans, or take your information. See a mistake? tell us.

Sources: standardized benefits from Medicare.gov — compare Medigap plan benefits; high-deductible amounts and the Plan C/F eligibility rule from the CMS F, G & J deductible announcements; open-enrollment and guaranteed-issue rules from Medicare.gov — Medigap. Enrollment context from KFF and MedPAC. Medicare has neither reviewed nor endorsed this page.