Health Insurance
Medicare Supplement (Medigap) Plans A, B, G, N: Which One Fits You?
By the PolicyZen Team · Updated March 2026 · 10 min read
Original Medicare (Parts A and B) covers about 80% of approved medical costs. The remaining 20% — plus deductibles, copays, and unlimited exposure on long hospital stays — is left to you. Medicare Supplement insurance, known as Medigap, fills those gaps.
There are 10 standardized Medigap plan letters (A, B, D, G, K, L, M, N — and formerly C and F for pre-2020 enrollees). Plans G and N are the most popular for new enrollees today. Here's what each covers and how to choose.
Key rule: Medigap plans are standardized by the federal government — a Plan G from Aetna covers the exact same benefits as a Plan G from Mutual of Omaha. The only difference is price, company financial strength, and customer service. Shop price aggressively because benefits are identical.
The Gaps Medigap Fills
- Part A hospital deductible: $1,676 per benefit period in 2026 (not annual — per admission, with no cap on how many you can have in a year)
- Part B coinsurance: 20% of all outpatient services with no cap
- Part B deductible: $257/year in 2026 (only covered by legacy Plan C and F)
- Skilled nursing facility coinsurance: Days 21–100 cost $209.50/day in 2026
- Foreign travel emergency: Medicare generally doesn't cover care outside the US
Coverage Comparison: The Plans That Matter Most
| Benefit | Plan A | Plan B | Plan G ★ | Plan N ★ |
|---|
| Part A coinsurance & hospital costs | ✓ | ✓ | ✓ | ✓ |
| Part B coinsurance (20%) | ✓ | ✓ | ✓ | ✓ (copays apply) |
| Part A hospice care coinsurance | ✓ | ✓ | ✓ | ✓ |
| Part A deductible ($1,676) | ✗ | ✓ | ✓ | ✓ |
| Skilled nursing facility coinsurance | ✗ | ✗ | ✓ | ✓ |
| Foreign travel emergency (80%) | ✗ | ✗ | ✓ | ✓ |
| Part B deductible ($257) | ✗ | ✗ | ✗ | ✗ |
| Part B excess charges | ✗ | ✗ | ✓ | ✗ |
★ Most popular plans for new Medicare enrollees since 2020
Plan G vs. Plan N: The Real Choice
Plan G is the most comprehensive plan available to new Medicare enrollees (Plan F, which also covers the Part B deductible, was discontinued for new enrollees after January 1, 2020). Plan G covers everything except the annual Part B deductible ($257). After that deductible, you pay nothing — no copays, no coinsurance, no excess charges.
Plan N costs less than Plan G but has two additional cost-sharing elements: up to $20 copays for office visits and up to $50 for ER visits (waived if admitted). Plan N also does NOT cover Part B excess charges — meaning if a provider doesn't accept Medicare assignment, they can bill up to 15% above Medicare's approved amount, and you're responsible for that excess.
The Medigap open enrollment window closes. You have a 6-month window starting the month you turn 65 AND are enrolled in Part B during which insurers cannot deny you coverage or charge more for pre-existing conditions. After this window, insurers can medically underwrite — meaning they can refuse coverage or charge much higher premiums based on your health. This window does not reopen in most states. Enroll in Medigap during this window even if you're healthy.
Can I have Medigap and Medicare Advantage?
No. Medigap supplements Original Medicare (Parts A and B). Medicare Advantage replaces Original Medicare. You cannot have both simultaneously. If you choose Medicare Advantage, your Medigap policy provides no benefit — and if you later want to switch back to Original Medicare + Medigap, you may face medical underwriting for the Medigap policy in most states.
Does Medigap cover prescription drugs?
No. Medigap policies don't cover Part D (prescription drugs). If you have Original Medicare + Medigap, you should also enroll in a standalone Part D prescription drug plan. Missing the Part D enrollment window triggers a permanent late enrollment penalty.
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