How Medigap works
Original Medicare leaves sizable gaps. In 2026 a hospital stay carries a $1,736 Part A deductible for each benefit period, and after the $283 Part B deductible you owe 20% of the Medicare-approved amount for doctor visits, outpatient surgery and most other services, with no yearly limit. Medigap policies fill those gaps.
When you get care, Medicare pays its share first. Most Medigap insurers then receive your Part B claims directly from Medicare and pay the doctor what your policy covers, leaving you only the remainder. You need both Part A and Part B to buy a policy, and you keep paying the Part B premium, $202.90 a month in 2026 or more with IRMAA, on top of the Medigap premium.
Each policy covers one person, so spouses buy separate policies. There are 10 standardized plans, lettered A–D, F, G and K–N, although Massachusetts, Minnesota and Wisconsin standardize theirs differently. Some states also sell Medicare SELECT policies, which may require you to use certain hospitals and doctors in exchange for a lower premium.
Plan G, Plan N and the other Medigap letters
Every lettered plan pays Part A hospital coinsurance and an extra 365 days of hospital care after Medicare’s days run out. They differ mainly on the two deductibles, on Part B excess charges, the amounts above Medicare’s approved rate that some doctors may legally bill, and on care abroad.
Plan G is the most complete plan open to people new to Medicare: it covers everything except the $283 Part B deductible. Plans C and F also cover that deductible, but they can’t be sold to anyone who became eligible for Medicare on or after January 1, 2020. Plan N covers Part B coinsurance except copays of up to $20 for some office visits and up to $50 for an emergency room visit that doesn’t lead to admission, and it doesn’t cover excess charges.
Plans K and L pay 50% and 75% of most costs until you reach a yearly out-of-pocket limit of $8,000 or $4,000 in 2026 plus the Part B deductible; after that they pay 100%. Some states also sell high-deductible versions of Plans F and G, where you pay the first $2,950 of covered costs in 2026 before the policy pays. Plans C, D, F, G, M and N pay 80% of emergency care abroad in the first 60 days of a trip, after a $250 yearly deductible, up to $50,000 over your lifetime.
When to buy: the six-month Medigap open enrollment
Timing matters more for Medigap than for any other part of Medicare. Your Medigap Open Enrollment Period lasts six months and starts the first month you are both 65 or older and enrolled in Part B. During it, an insurer must sell you any policy it offers and can’t charge more because of your health. It happens once and doesn’t repeat every year.
After it ends, there is no federal guarantee that an insurer will sell you a policy, and one that does may charge more for past or present health problems. Federal guaranteed issue rights reopen the door only in specific situations, usually with an application due no more than 63 days after the old coverage ends: your Medicare Advantage plan leaves Medicare or your area, you use a Medicare Advantage trial right within its first 12 months, or a Medigap insurer goes bankrupt or misleads you. Some states add broader rights of their own.
If you delay Part B because you still have job-based coverage, your Medigap window waits until you sign up for Part B, which you can do without penalty when that coverage ends, as explained under Medicare enrollment periods. People under 65 on Medicare because of a disability have no federal right to buy Medigap, though some states require insurers to sell to them.
What Medigap doesn’t cover
Medigap only pays your share of services Original Medicare covers, plus emergency care abroad on some plans. Policies sold since 2006 include no prescription drug coverage, so most people pair Medigap with a separate Part D plan, and going without creditable drug coverage can bring a late enrollment penalty. Medigap also won’t pay any of a Medicare Advantage plan’s costs. Tax treatment is uneven too: IRS rules let a health savings account pay Medicare premiums tax-free after 65, but they specifically exclude Medigap premiums. Items Medigap generally leaves out:
- Long-term care, such as a nursing home stay, which is where long-term care insurance comes in.
- Routine vision and dental care, eyeglasses and hearing aids.
- Private-duty nursing.
Illustrative numbers
A hospital stay plus follow-up care in 2026, with and without Plan G
Part A deductible, one hospital stay$1,736
Part B deductible$283
20% coinsurance on $25,000 of approved Part B care after the deductible$5,000
Out of pocket with Original Medicare alone$7,019
Out of pocket with high-deductible Plan G$2,950
Out of pocket with standard Plan G$283
Plan G turns a $7,019 year into $283, and its high-deductible version caps it at $2,950, assuming doctors who accept Medicare’s approved rate. In exchange you pay a premium every month whether or not you use care, so in a healthy year the policy costs more than it pays out. Its value is in capping the bad year, much like the out-of-pocket limit in Medicare Advantage.
At a glance
What each standardized Medigap plan pays (C and F only for those eligible before 2020)
| Plan | Part A deductible ($1,736) | Part B deductible ($283) | Part B coinsurance | Excess charges |
|---|---|---|---|---|
| A | No | No | 100% | No |
| B | 100% | No | 100% | No |
| C | 100% | 100% | 100% | No |
| D | 100% | No | 100% | No |
| F | 100% | 100% | 100% | 100% |
| G | 100% | No | 100% | 100% |
| K | 50% | No | 50% until the $8,000 limit | No |
| L | 75% | No | 75% until the $4,000 limit | No |
| M | 50% | No | 100% | No |
| N | 100% | No | 100% minus copays up to $20 or $50 | No |
Put it in your plan
Medigap in MoneyWhatIf
In MoneyWhatIf, a Medigap premium goes in the monthly supplemental amount on the Medicare setting, added per enrolled person from the plan year each person turns 65, on top of the 2026 Part B premium of $202.90 and a $38.99 Part D placeholder. The total grows at plan inflation plus two percentage points, a healthcare-cost assumption rather than a forecast of future premiums. A healthcare spending category can also step down as each person turns 65, so private coverage before Medicare isn’t counted twice. Deductibles, coinsurance and uncovered care aren’t modeled.
Open your forecastCommon questions
Medigap FAQs
What is the difference between Medigap and Medicare Advantage?
Medigap supplements Original Medicare: Medicare pays its share of each bill and your policy pays most of the rest, at any provider in the U.S. that takes Medicare. Medicare Advantage replaces that arrangement with a private plan that has its own network, copays and yearly limit, usually with drug coverage built in. You can have one or the other, not both, and Medigap can’t pay a Medicare Advantage plan’s costs.
Is Plan G or Plan N better?
Neither is better for everyone. Both leave you the $283 Part B deductible in 2026 and pay the Part A deductible and coinsurance in full. Plan G then pays the rest of your Medicare-covered costs, including excess charges. Plan N adds copays of up to $20 for some office visits and $50 for emergency room visits that don’t lead to admission, and leaves excess charges to you, which arise only when a doctor doesn’t accept Medicare’s approved amount as full payment. Weigh the premium gap against how often you use care.
Can a Medigap insurer cancel your policy because of your health?
No. Standardized Medigap policies renew automatically every year, even if your health changes. The insurer can end your coverage only if you stop paying premiums, were untruthful on your application, or the company goes bankrupt or out of business. Your premium can still rise, depending on how the insurer rates its policies and how its costs change.
Can you switch Medigap plans later?
You can apply for a different policy at any time, but outside your six-month open enrollment and specific guaranteed issue situations, federal law doesn’t require an insurer to accept you or charge standard rates, so health questions may decide the answer. Some states give broader rights. If a new insurer accepts you, you get a 30-day free look period before you must cancel the old policy, and the new one may make you wait up to six months to cover new benefits or a pre-existing condition.
Are Medigap premiums tax-deductible?
They count as medical expenses, so they can be deducted as itemized deductions, but only the part of your total medical costs above 7.5% of adjusted gross income. That threshold means many retirees get no benefit. And unlike Part B, Part D and Medicare Advantage premiums, Medigap premiums can’t be paid tax-free from a health savings account.