Medicare Supplement Plan C 2027: Coverage, Who Can Buy It and Plan C vs Plan F

Reviewed by Russell Noga, Licensed Medicare Insurance Broker (all 50 states) — Last updated October 29, 2026

Medicare Supplement Plan C covers almost all of your Medicare cost sharing, including the Part B deductible, but you can only buy it if you were first eligible for Medicare before January 1, 2020. It pays everything Plan F pays except Part B excess charges. If you became eligible in 2020 or later, Plan G or Plan D gives you similar coverage.

Plan C used to be one of the most popular Medicare Supplement plans. A 2015 federal law, known as MACRA, stopped plans from covering the Part B deductible for people new to Medicare. Since January 1, 2020, Plan C and Plan F have been closed to anyone who became eligible on or after that date.

If you already have Plan C, you can keep it. This guide explains what Plan C covers in 2027, who can still buy it, and how it compares with other letters. To see every plan side by side, use our Medicare Supplement plans comparison chart.

Plan C is a standardized plan. That means its benefits are the same no matter which company sells it, in most states. The only thing that changes from one company to the next is the price and the service.

Benefits from the Medicare.gov plan chart. Plans are standardized differently in Massachusetts, Minnesota and Wisconsin.

In plain terms, Plan C pays your share of almost every Medicare-approved bill. You pay your monthly premium, and you may owe Part B excess charges if a doctor does not accept Medicare assignment.

The rule is based on when you first became eligible for Medicare, not when you signed up. Plans that cover the Part B deductible, Plan C and Plan F, cannot be sold to people who became eligible on or after January 1, 2020.

The names sound alike, but they are two very different things. Medicare Supplement Plan C is a letter plan that works alongside Original Medicare. Medicare Part C is another name for Medicare Advantage, which replaces Original Medicare with a private plan.

You cannot use a Medicare Supplement plan and a Medicare Advantage plan at the same time.

If you want to understand the bigger choice, read our guide to Medicare Supplement vs Medicare Advantage. This page covers only the Medicare Supplement plan.

Plan C and Plan F are almost twins. Both pay the Part B deductible, and both are closed to people new to Medicare since 2020. The one difference is Part B excess charges.

Benefits from Medicare.gov.

Excess charges happen when a doctor does not accept Medicare’s approved amount as full payment. By law, that doctor can bill up to 15% more than the approved amount, and Plan C does not pay it. A few states limit or ban excess charges, so the gap may matter less where you live. Learn more in our Medicare Supplement Plan F guide.

If you are new to Medicare, Plan G and Plan D are the closest plans you can buy. Neither covers the Part B deductible, which is $283 in 2026 and projected at $292 for 2027.

So the math is simple. If Plan C costs more than about $292 a year above Plan D in 2027, you are paying extra for a deductible you could pay yourself. The same check works for Plan G, which also adds excess charge protection.

There is no single right answer. Plan C still gives strong coverage, so the question is whether you are paying too much for it.

Plan C fits best if you like having almost every bill paid, your doctors accept Medicare assignment, and your rate is fair. If you want to know how switching works, read can you change Medicare Supplement plans.

Medicare Supplement Plan C pays almost all Medicare cost sharing, including the Part B deductible, but it does not cover Part B excess charges. Only people first eligible for Medicare before January 1, 2020 can buy it. If you have Plan C, compare it against Plan G and Plan D each year to make sure the extra coverage is worth the price.