What Medigap is (and isn't)
Medigap (also called Medicare Supplement Insurance) is private insurance that pays some or all of the costs that Original Medicare doesn't cover. Medigap is not Medicare Advantage — it works alongside Original Medicare, not instead of it.
You pay your Part B premium ($185/month) plus your Medigap premium. In exchange, your Medigap plan covers gaps like the Part B 20% coinsurance, the Part A deductible, and in some plans, foreign travel emergencies.
Important: Medigap plans do NOT cover prescription drugs. You need a separate Part D plan for drug coverage.
The standardized Medigap plans
In most states, Medigap plans are standardized — Plan G from one insurer covers the same benefits as Plan G from another. The only difference is the premium and the insurer's reputation for service.
| Plan | Part A coinsurance | Part B coinsurance | Part A deductible | Part B deductible | Foreign travel |
|---|---|---|---|---|---|
| Plan F* | ✅ | ✅ | ✅ | ✅ | 80% |
| Plan G | ✅ | ✅ | ✅ | ❌ | 80% |
| Plan N | ✅ | Copays up to $20 | ✅ | ❌ | 80% |
| Plan K | 50% | 50% | 50% | ❌ | ❌ |
| Plan L | 75% | 75% | 75% | ❌ | ❌ |
*Plan F only available to those who turned 65 before January 1, 2020.
Plan G vs Plan N — the main choice in 2026
Since Plan F is no longer available to new enrollees, most people choosing Medigap in 2026 are deciding between Plan G and Plan N.
Plan G covers everything except the Part B deductible ($257/year in 2026). After you pay that deductible once, Plan G covers 100% of your Medicare-approved costs. It's the most comprehensive plan available to new enrollees.
Plan N has a lower premium than Plan G but requires small copays — up to $20 for doctor visits and up to $50 for emergency room visits. If you're healthy and don't visit the doctor often, Plan N can save money overall.
The critical Medigap Open Enrollment Period
You have a 6-month Medigap Open Enrollment Period (OEP) that starts when you're both age 65+ AND enrolled in Part B. During this window, insurers cannot deny you coverage or charge you more based on health conditions.
⚠️ Miss this window and face health underwriting: After your Medigap OEP closes, insurers in most states can review your health history and charge higher premiums or deny coverage entirely. This is the most important timing decision in Medicare enrollment.
How to shop for Medigap
Since the benefits are standardized, shop on price and insurer stability. Compare quotes from multiple insurers for the same plan letter. Look for insurers with a long history and stable rates — some insurers raise rates aggressively after you enroll.