What Is the Most Expensive Medicare Supplement Plan? (2026)

Direct Answer: The Most Expensive Medigap Plan

It depends on when you became eligible for Medicare. Plan C carries the highest average Medigap premium in 2026, with Plan F close behind, but both are closed to anyone newly eligible for Medicare on or after January 1, 2020. Among plans still open to new enrollees, Plan G is typically the most expensive because it covers nearly every gap except the $283 Part B deductible in 2026.

Why Plan C and Plan F Cost More Than Every Other Medigap Letter

Plan C and Plan F are the only two Medigap letters that pay the Medicare Part B deductible for you, which is $283 in 2026, on top of covering every other Medicare Part A and Medicare Part B gap: the $1,736 Part A deductible, Part A and Part B coinsurance, skilled nursing coinsurance, and the first three pints of blood. Neither letter touches prescription drugs; you still need a standalone Medicare Part D plan for that, since Medigap policies sold since 2006 cannot include drug coverage. That first-dollar design means a Plan C or Plan F holder almost never pays anything out of pocket for Medicare-covered services, and insurers price that near-total protection higher than every other letter because they absorb nearly all of the claims risk.

Congress closed both plans to new enrollees through the Medicare Access and CHIP Reauthorization Act (MACRA), effective for anyone who became eligible for Medicare on or after January 1, 2020. Lawmakers wanted to remove the incentive for beneficiaries with first-dollar coverage to seek more care than necessary because they never saw a bill. If you already held a Plan C or Plan F policy before that date, you can keep it and even switch insurers for the same letter, but no one newly eligible for Medicare can purchase either plan today.

The Priciest Plan You Can Still Buy: Plan G

Plan G is the most comprehensive Medigap policy available to anyone who became Medicare-eligible on or after January 1, 2020, and it is consistently the most expensive plan letter still open to new business. It covers everything Plan F covers except the $283 Part B deductible in 2026, so once you pay that one deductible each year, Plan G pays essentially every other Medicare-approved cost for the rest of the year at any provider that accepts Medicare nationwide.

New Plan G quotes for a 65-year-old typically run $120 to $300 or more a month in 2026, depending heavily on your state's rating rules, your age at purchase, and the insurer you choose. KFF found the average premium among existing Plan G policyholders was $164 a month nationally, ranging from about $140 in Washington, D.C., to $236 in New York, and rates have climbed further since as insurers filed double-digit increases in several states. Because every Plan G policy covers the identical federally standardized benefits, the only real difference between a $150 quote and a $280 quote for the same letter is the insurer and how it prices risk.

What Pushes Medigap Premiums Higher

Five factors decide whether you pay near the low end or the high end of a plan letter's price range in 2026, and none of them change the benefits you receive, only what you pay for them.

• Rating method: community-rated states charge everyone the same regardless of age, issue-age-rated states lock in your starting age forever, and attained-age-rated states raise your premium every year you get older.
• Age at purchase: buying at 65 locks in a lower starting rate in most states than waiting until 70 or 75.
• State: some states allow wide premium variation by ZIP code and insurer; others cap how much carriers can charge.
• Gender and tobacco use: many states permit insurers to charge men and women different rates and add a tobacco surcharge.
• Plan comprehensiveness: the more first-dollar coverage a letter provides, the higher its premium, which is exactly why Plan C and Plan F top every rate chart.

What You Risk Without Any Medigap Plan at All

The reason the priciest Medigap letters still sell is that Original Medicare alone leaves you exposed with no annual cap. Part A charges a $1,736 deductible per benefit period in 2026, so two unrelated hospital stays in one year can mean paying that deductible twice. Part B charges a $283 deductible in 2026, then leaves you responsible for 20% coinsurance on nearly every covered service for the rest of the year with no ceiling, so a single surgery or extended hospitalization can generate tens of thousands of dollars in coinsurance bills. Against that backdrop, even a $300-a-month Plan G premium can be the cheaper outcome for someone who uses a lot of care.

Cheaper Alternatives If the Priciest Plans Cost Too Much

Plan C, Plan F, and Plan G sit at the top of the price chart, but five lower-cost paths can still limit your Medicare exposure in 2026 without that top-tier premium.

• Plan N: runs $90 to $250 or more a month in 2026 and covers the same core benefits as Plan G in exchange for a small office visit copay (up to $20) and emergency room copay (up to $50).
• High-deductible Plan G: often $30 to $80 a month, requires you to pay a separate annual deductible ($2,950 in 2026) before the plan pays anything, then covers the rest like standard Plan G.
• Plan K and Plan L: share Medicare cost-sharing 50/50 or 75/25 with you up to an annual out-of-pocket limit, roughly $87 to $180 a month, for beneficiaries who want a middle ground between premium and risk.
• Medicare Advantage: frequently a $0 monthly premium with a capped in-network maximum out-of-pocket of up to $9,250 in 2026, though it trades Medigap's nationwide freedom for HMO or PPO networks.
• Medicare Savings Programs (QMB, SLMB, QI) or full Medicaid dual eligibility: can pay your Part B premium and cap Original Medicare cost-sharing for low-income beneficiaries with no Medigap premium at all.

How to Shop for a Medigap Plan Without Overpaying

Because every insurer selling the same plan letter must offer identical federally standardized benefits, the price you pay comes down entirely to timing and shopping, not coverage quality. Your 6-month Medigap Open Enrollment Period starts the month you turn 65 and are enrolled in Part B, and during that window insurers must sell you any plan they offer at their best available rate with no medical underwriting. Applying outside that window or a guaranteed-issue event means most states allow insurers to medically underwrite you, which can raise your premium or get you denied outright for a preexisting condition like diabetes or heart disease.

What is the most expensive Medicare Supplement plan overall?

Plan C carries the highest average premium of any standardized Medigap plan in 2026, running roughly $180 to $390 or more a month, with Plan F close behind. Both cover the $283 Part B deductible and nearly every other Medicare gap, but neither is available to anyone who became Medicare-eligible on or after January 1, 2020.

What is the most expensive Medigap plan I can still buy?

Plan G is the most expensive plan open to new Medicare enrollees in 2026, typically running $120 to $300 or more a month. It covers every Medicare Part A and Part B gap except the $283 Part B deductible, which you pay once each year before Plan G takes over.

Why are Plan C and Plan F closed to new enrollees?

Congress closed both plans through the Medicare Access and CHIP Reauthorization Act (MACRA), effective for anyone newly eligible for Medicare on or after January 1, 2020. Lawmakers wanted to stop first-dollar coverage plans from encouraging beneficiaries to use more care than necessary. Beneficiaries who already held Plan C or Plan F before that date can keep their policy.

Is a more expensive Medigap plan actually better coverage?

Not necessarily better, just more comprehensive on the deductible. Every Medigap plan letter is federally standardized, so a Plan G from one insurer covers exactly the same benefits as a Plan G from any other insurer; the premium difference between insurers reflects pricing, not coverage quality. A higher-priced letter like Plan C, F, or G simply pays for more of your cost-sharing than a cheaper letter like Plan N or K.

What happened to Medicare Supplement Plan J?

Plan J was historically the most comprehensive, and most expensive, Medigap letter ever sold, but insurers stopped selling it to new applicants on June 1, 2010. Existing Plan J holders can keep their policy, though premiums have climbed sharply for the remaining, aging risk pool since no new members have joined in over a decade.

Is Medicare Advantage cheaper than the most expensive Medigap plans?

Usually on premium. Most Medicare Advantage plans in 2026 carry a $0 monthly premium versus $120 to $390 or more for top-tier Medigap letters, but Medicare Advantage caps your annual exposure at up to $9,250 for in-network care instead of the near-total protection Plan C, F, or G provide, and it routes you through a network.

What is the cheapest Medigap plan to offset a high-cost letter?

High-deductible Plan G is typically the cheapest way to get Plan G's benefits, often $30 to $80 a month in 2026, in exchange for paying $2,950 out of pocket before the plan starts covering costs. Plan K and Plan L also run lower, around $87 to $180 a month, by sharing cost-sharing with you up to an annual limit.

Can I switch from an expensive Medigap plan to a cheaper one later?

Yes, but usually with medical underwriting. Outside your one-time 6-month Medigap Open Enrollment Period or a guaranteed-issue event, insurers in most states can review your health history before approving a switch to a different letter or a different insurer, which can mean a rate increase or denial for a preexisting condition.