What's the Best Medigap Plan for Most Medicare Beneficiaries?

If you're enrolled in Original Medicare — Part A and Part B — you already know the coverage has real gaps. There's no cap on out-of-pocket spending, a Part A hospital deductible of $1,676 per benefit period in 2026, and a Part B deductible of $257 per year. A serious illness or extended hospital stay can cost tens of thousands of dollars out of pocket. That's exactly what Medigap, also called Medicare Supplement Insurance, is designed to fix. But with ten standardized plan types labeled A through N (not all sold in every state), choosing the right one can feel overwhelming. The good news: for most beneficiaries, the field narrows quickly to two serious contenders — Plan G and Plan N.

Plan G has become the gold standard for comprehensive Medigap coverage since Plan F was closed to new enrollees in 2020. Plan F, which covered everything including the Part B deductible, is still available to people who were eligible for Medicare before January 1, 2020, but it typically carries higher premiums and is no longer an option for newer enrollees. Plan G covers the Part A deductible ($1,676 per benefit period in 2026), Part A coinsurance and hospital costs up to an additional 365 days after Medicare benefits are exhausted, Part B coinsurance or copayments, the first three pints of blood, Part A hospice care coinsurance, skilled nursing facility coinsurance, and foreign travel emergency care (up to plan limits). The only thing Plan G does not cover is the annual Part B deductible. Once you pay that $257 yourself at the start of each year, Plan G picks up essentially everything else Medicare doesn't cover.

Plan N works differently and is worth serious consideration if you're in relatively good health and want to reduce your monthly premium. Like Plan G, Plan N covers the Part A deductible, skilled nursing facility coinsurance, and foreign travel emergencies. But it does not cover Part B excess charges — the extra amount some doctors who don't accept Medicare assignment can legally bill above Medicare's approved rate, up to 15 percent more. More importantly for day-to-day use, Plan N requires a copay of up to $20 for office visits and up to $50 for emergency room visits that don't result in an inpatient admission. The monthly premium savings between Plan G and Plan N can range from $30 to $80 or more depending on your age, gender, and location. If you're healthy and see your doctor only a few times a year, those savings can outpace the copays. But if you have chronic conditions requiring frequent specialist visits, Plan G's higher premium may actually cost less over the course of a year.

Premium pricing for Medigap varies significantly by insurer and by how they calculate your rate. There are three pricing methods: community-rated (everyone pays the same regardless of age), issue-age-rated (your premium is based on your age when you first buy the policy and doesn't automatically increase as you get older), and attained-age-rated (your premium increases as you age, which is the most common method and can lead to steep costs in your 80s). When comparing plans, always ask which pricing method the insurer uses. Two insurers offering identical Plan G coverage can charge very different premiums — and the cheaper option today may not be cheaper at 80. The State Health Insurance Assistance Program (SHIP) in your state offers free, unbiased counseling to help you compare options; you can find your local SHIP counselor at shiphelp.org.

Timing your Medigap purchase is just as important as choosing the right plan. Your Medigap Open Enrollment Period is a one-time, six-month window that begins the first month you are both 65 or older and enrolled in Medicare Part B. During this window, insurers are required by federal law to sell you any Medigap plan they offer at standard rates, regardless of your health history. They cannot charge you more because of a pre-existing condition or deny you coverage. Once this window closes, you lose those federal protections in most states. Insurers can then use medical underwriting — reviewing your health history — and can legally charge you more or refuse to sell you a policy if you have conditions like diabetes, heart disease, or a history of cancer.

Several states have enacted stronger consumer protections that go beyond federal rules. If you live in California, Idaho, Illinois, Kentucky, Louisiana, Maine, Maryland, Missouri, Nevada, New Jersey, New York, Oklahoma, or Oregon, you may have a birthday rule — a 30-day window each year around your birthday during which you can switch to a Medigap plan with equal or lesser benefits without medical underwriting. New York and Connecticut go even further, requiring guaranteed issue rights year-round, meaning insurers must sell you a Medigap policy at any time regardless of health status. If you live in one of these states and missed your initial enrollment window, you may still have options that aren't available elsewhere.

High-deductible versions of Plan G and Plan F also exist and deserve mention for beneficiaries who are generally healthy and want the lowest possible monthly premium. High-deductible Plan G requires you to pay a deductible of $2,870 in 2026 before the plan begins covering costs, but monthly premiums can be dramatically lower — sometimes under $50 per month for a 65-year-old. This structure functions almost like a catastrophic backstop: you handle routine costs yourself, but you're protected from truly ruinous expenses. It's a reasonable choice for someone with significant savings who wants to self-insure for minor costs while avoiding financial catastrophe from a major illness.

Plan K and Plan L are cost-sharing plans that cover only a percentage of most benefits — 50 percent and 75 percent respectively — and have annual out-of-pocket limits ($7,220 for Plan K and $3,610 for Plan L in 2026). These plans carry lower premiums but expose you to more cost-sharing, and most financial advisors and Medicare counselors consider them less competitive than Plan G or Plan N for the majority of beneficiaries. Plan A, the most basic Medigap plan, covers only Part A coinsurance and hospital costs, Part B coinsurance, blood, and hospice coinsurance — it does not cover the Part A deductible, making it a poor value for most people given that a single hospital stay can trigger that $1,676 deductible.

One critical point that trips up many new beneficiaries: Medigap plans are not the same as Medicare Advantage plans. Medicare Advantage (Part C) replaces Original Medicare with a private plan that typically includes drug coverage and extra benefits but uses networks and prior authorization. Medigap supplements Original Medicare and works alongside it — you keep your Medicare card and can see any doctor or specialist in the country who accepts Medicare, with no network restrictions. If you value that freedom, particularly if you travel frequently, see specialists at major academic medical centers, or split time between states, Medigap paired with a standalone Part D drug plan may serve you better than Medicare Advantage despite the higher monthly premium.

To compare actual Medigap premiums in your area, use the Medicare Plan Finder at medicare.gov or call 1-800-MEDICARE (1-800-633-4227). Because all Plan G policies sold in your state must cover the same benefits by law, the only meaningful differences between insurers are price, financial stability, and customer service. Check insurer ratings through AM Best or your state insurance department before enrolling. Premiums for the same plan can vary by hundreds of dollars per year between insurers for identical coverage — shopping carefully at the outset, and reviewing your options annually, can make a meaningful difference in what you pay over a decade of retirement.