Medigap plan letters explained: what A through N actually cover

A plain-English guide to the ten standardized Medicare Supplement plans, the 2026 deductibles they fill, and why Plan G and Plan N dominate new sales.

Medicare Supplement insurance, usually called Medigap, pays some or all of the costs Original Medicare leaves behind. The plans are standardized by federal law: a Plan G from one insurer has exactly the same benefits as a Plan G from any other insurer. The only things that differ between companies are price, how prices rise over time, customer service and optional extras.

That standardization is the most useful fact for a shopper. It means comparing Medigap plans is really two separate decisions: which letter fits your budget and risk tolerance, and which company offers that letter at a fair price.

The benefit grid

* Plans C and F can only be bought by people who first became eligible for Medicare before January 1, 2020. Massachusetts, Minnesota and Wisconsin use their own standardized designs.

What the gaps are in 2026

Original Medicare in 2026 leaves you responsible for:

• The Part A hospital deductible of $1,736 per benefit period (not per year).
• Hospital coinsurance of $434 a day for days 61 to 90 and $868 a day for lifetime reserve days.
• Skilled nursing coinsurance of $217 a day for days 21 to 100.
• The Part B deductible of $283 a year.
• 20% of Part B costs with no annual cap: doctor visits, outpatient surgery, imaging, dialysis, chemotherapy.

That last item is the reason most people buy Medigap. There is no out-of-pocket maximum in Original Medicare, and 20% of a cancer treatment year can run into tens of thousands of dollars.

Why Plan G became the default

Plan G covers everything except the Part B deductible. Since Plan F closed to new enrollees in 2020, it is the most complete plan most people can buy, and its premium is usually much lower than F's was, because F's premium included the deductible plus insurer overhead on it. We work through the numbers in our Plan G versus Plan N comparison.

Plan N: lower premium, small copays

Plan N covers the same big-ticket items as G but asks you to pay up to $20 for some office visits and up to $50 for emergency room visits that don't result in admission, and it does not cover Part B excess charges. For healthy people who see doctors a few times a year, the premium saving usually outweighs the copays.

Plans K and L: built-in caps

Plans K and L pay a share (50% or 75%) of most costs until you hit an annual out-of-pocket limit: $8,000 for K and $4,000 for L in 2026. They suit people who want catastrophic protection at a lower premium. See how K and L cost sharing works.

What no Medigap plan covers

Prescription drugs (you need a separate Part D plan), routine dental, vision and hearing, long-term custodial care, and the Part B premium itself. If you want those extras bundled, that is a Medicare Advantage question rather than a Medigap one; this comparison walks through the trade-offs.

Questions people ask

Are Medigap plans the same from every insurance company?

Yes, the benefits for each letter are standardized by federal law. Price, rate increase history and service differ.

Can I still buy Plan F?

Only if you were first eligible for Medicare before January 1, 2020.

Does Medigap cover prescriptions?

No. Plans sold since 2006 do not include drug coverage; you need a separate Part D plan.

Is there a network?

No. Medigap works with any provider in the U.S. that accepts Medicare.

Independent educational site. Not affiliated with or endorsed by the U.S. government, the federal Medicare program, or any insurance company. Figures are 2026 amounts published by CMS unless noted; check Medicare.gov for your situation.