Medicare Supplement (Medigap) plans

What is Medicare Supplement insurance?

Medicare Supplement Insurance — commonly called Medigap — is private insurance that helps pay for out-of-pocket costs that Original Medicare (Parts A and B) doesn't fully cover. These costs include deductibles, coinsurance, and copayments that can add up quickly, especially if you need hospital care or frequent doctor visits.

Medigap plans are sold by private insurance companies, but they're standardized by the federal government. That means Plan G from one company covers exactly the same benefits as Plan G from another company — the only difference is the price.

How Medigap works

When you receive a medical service covered by Original Medicare:

1. Medicare pays its share — typically 80% of the approved amount for Part B services
2. Your Medigap plan pays some or all of the remaining costs — depending on which plan you have
3. You pay little to nothing — for covered services, beyond your monthly premium

Key facts about Medigap

• 10 standardized plans are available in most states, labeled A through N (some letters are no longer sold)
• You must have Original Medicare (Parts A and B) to buy a Medigap plan
• You cannot have Medicare Advantage and a Medigap plan at the same time
• Medigap does not cover prescription drugs — you need a separate Part D plan for that
• You can see any doctor who accepts Medicare, anywhere in the country — no network restrictions
• Plans are guaranteed renewable — your plan can't be cancelled as long as you pay your premium

The 10 standardized plans

Each lettered plan offers a specific set of benefits. The most popular plans are Plan G (most comprehensive for new enrollees) and Plan N (lower premium with small copays for some visits).

See all 10 plans compared side by side →

What Medigap doesn't cover

• Prescription drugs (use Part D for this)
• Long-term care (nursing home custodial care)
• Dental, vision, or hearing (unless provided by your plan as an extra)
• Private-duty nursing

Medigap vs. Medicare Advantage

You have to choose one path or the other — you can't have both. Medigap works with Original Medicare and gives you maximum doctor choice. Medicare Advantage replaces Original Medicare and often includes drug coverage and extras like dental, but limits you to a provider network.

Compare Medigap and Medicare Advantage →