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Medigap plan-letter comparison
The federal Medigap system has been letter-standardized since the 1990 NAIC Medicare Supplement Standardization Act. Today, ten federal plan letters (A, B, C, D, F, G, K, L, M, N) cover federally-frozen sets of benefits. Within a given letter, every insurer’s policy covers identical benefits — only the premium varies.
Why standardization matters
Before 1990, Medigap policies were a maze of incompatible products. Comparing them required reading dense policy language. The NAIC standardization act collapsed the market into a small number of standardized letters, so beneficiaries can compare across insurers on price alone (within a letter). The benefits matrix is federally frozen by CMS — no insurer may deviate from the cells defined for each letter.
The federal benefits matrix, verbatim from CMS
The matrix below is verbatim from medicare.gov’s federal benefits page. The cell categorical values (covered / not covered / 50% / 75%) are CMS-frozen.
| Benefit | A | B | CMACRA grandfathered | D | FMACRA grandfathered | G | K | L | M | N |
|---|---|---|---|---|---|---|---|---|---|---|
| Part A coinsurance and hospital costs (up to an additional 365 days after Medicare benefits are used up) | ||||||||||
| Part B coinsurance or copayment | 50% | 75% | See note | |||||||
| Blood (first 3 pints) | 50% | 75% | ||||||||
| Part A hospice care coinsurance or copayment | 50% | 75% | ||||||||
| Skilled nursing facility care coinsurance | 50% | 75% | ||||||||
| Part A deductible | 50% | 75% | 50% | |||||||
| Part B deductible | ||||||||||
| Part B excess charges | ||||||||||
| Foreign travel emergency (up to plan limits) | ||||||||||
| Out-of-pocket limit (applies to Plans K and L only) |
Reading the matrix: ✓ = the plan covers 100% of the federally-defined benefit; 50%/75% = the plan pays that share of the benefit; ✗ = the plan does not cover the benefit. Plans C and F are closed to people newly eligible for Medicare on or after 2020-01-01 per MACRA 2015 grandfathering. Massachusetts, Minnesota, and Wisconsin do not use the federal 10-letter system; see your state page for the state-specific Medigap structure.
Plan footnotes
- 1. Plan N · Part B coinsurance or copayment: Plan N pays 100% of the Part B coinsurance, except for a copayment of up to $20 for some office visits and up to a $50 copayment for emergency room visits that don't result in inpatient admission. (Verify CMS dollar amounts at annual review cron.)
- 2. Plan C · Part B deductible: Plans C and F are closed to new Medicare-eligible beneficiaries on or after 2020-01-01 per MACRA 2015. Beneficiaries first eligible for Medicare BEFORE 2020-01-01 may still purchase Plans C and F.
- 3. Plan F · Part B deductible: Plans C and F are closed to new Medicare-eligible beneficiaries on or after 2020-01-01 per MACRA 2015. Beneficiaries first eligible for Medicare BEFORE 2020-01-01 may still purchase Plans C and F.
- 4. Plan K · Out-of-pocket limit (applies to Plans K and L only): Plans K and L include an annual out-of-pocket limit. After the limit is met for the calendar year, Plan K (or L) pays 100% of covered services for the remainder of the year. For 2026, the Plan K limit is $8,000 and the Plan L limit is $4,000 (per CMS K & L Out-of-Pocket Limits Announcement, October 2025; statutory basis 42 U.S.C. § 1395ss(w)(2)).
- 5. Plan L · Out-of-pocket limit (applies to Plans K and L only): Plans K and L include an annual out-of-pocket limit. After the limit is met for the calendar year, Plan K (or L) pays 100% of covered services for the remainder of the year. For 2026, the Plan K limit is $8,000 and the Plan L limit is $4,000 (per CMS K & L Out-of-Pocket Limits Announcement, October 2025; statutory basis 42 U.S.C. § 1395ss(w)(2)).
Why Plan G is the de facto default for newly-eligible beneficiaries
Plan F was historically the most comprehensive policy because it covered the Part B deductible. MACRA 2015 closed Plan F (and Plan C) to people newly eligible for Medicare on or after 2020-01-01. Newly-eligible beneficiaries now choose among the open plans, and Plan G — which covers everything Plan F covers exceptthe Part B deductible — has become the de facto default. The trade-off: Plan G holders pay the Part B deductible (the 2026 amount is published annually by CMS) directly, but typically at a Plan G premium meaningfully lower than Plan F’s would be.
Why Plan N is the cost-conscious alternative
Plan N is structured around Plan-G-like coverage minus the Part B excess charge benefit, plus copays of up to $20 for some office visits and up to $50 for emergency room visits that don’t result in inpatient admission. Plan N typically prices below Plan G; for beneficiaries with infrequent office visits and no exposure to Part-B-excess-charging providers, Plan N can be a strong fit. Plan N is less attractive in markets where many providers charge above the Medicare-approved amount (Plan G covers those excess charges; Plan N does not).
The 3-state structural exception
Massachusetts, Minnesota, and Wisconsin do not use the federal A–N letter system. Each operates a state-specific Medigap structure that predates or is exempt from the 1990 NAIC standardization. If you live in one of those states, the federal benefits matrix above doesn’t apply — see your state page.
Federal Medigap plan-letter benefits matrix (CMS-standardized per 1990 NAIC Medicare Supplement Standardization Act)
Last verified:Source:medicare.gov — Compare Medigap Plan Benefits