Original Medicare (Parts A and B) is great, but it leaves you exposed to significant out-of-pocket costs. There's no annual cap on what you could spend. Medicare Supplement insurance - also called Medigap - fills these gaps.
What Does Medigap Cover?
Depending on the plan you choose, Medigap can help pay:
- Part A coinsurance and hospital costs (up to 365 days after Medicare benefits run out)
- Part A hospice care coinsurance or copays
- Part B coinsurance or copay (the 20% you'd normally pay)
- Part A deductible ($1,632 per benefit period in 2024)
- Part B deductible ($240 per year in 2024)
- Part B excess charges (if a doctor charges more than Medicare-approved amounts)
- Blood (first 3 pints)
- Foreign travel emergency (80% of emergency care abroad)
Without Medigap: Margaret needs knee replacement surgery. Her hospital stay costs $50,000. Medicare pays 80% after her deductible. She owes $10,000+ out of pocket.
With Medigap Plan G: Margaret pays her $240 Part B deductible. Her Medigap policy pays the remaining 20% that Medicare didn't cover. Her out-of-pocket cost: $240.
The Standardized Plans
Medigap plans are standardized by the federal government and labeled with letters. Each letter offers a specific set of benefits that's the same regardless of which insurance company sells it. The only differences between companies are price and customer service.
| Benefit | Plan G | Plan N | Plan F* |
|---|---|---|---|
| Part A coinsurance | Yes | Yes | Yes |
| Part B coinsurance | Yes | Yes** | Yes |
| Part A deductible | Yes | Yes | Yes |
| Part B deductible | No | No | Yes |
| Part B excess charges | Yes | No | Yes |
| Foreign travel emergency | Yes | Yes | Yes |
*Plan F is only available if you were Medicare-eligible before January 1, 2020.
**Plan N requires copays: up to $20 for office visits and up to $50 for ER visits (waived if admitted).
Most Popular Plans Today
Plan G is the most popular choice. It covers everything except the Part B deductible ($240/year). Since Plan F is no longer available to new enrollees, Plan G offers the most comprehensive coverage.
Plan N offers lower premiums in exchange for small copays ($20 for office visits, $50 for ER if not admitted). It's a good choice if you want to save on premiums and don't mind small, predictable copays.
Other plans exist (A, B, D, K, L, M), but G and N make up the vast majority of new enrollments. Unless you have a specific reason, start by comparing G and N in your area.
Key Benefits of Medigap
- No network restrictions - See any doctor or specialist who accepts Medicare, anywhere in the country
- No referrals needed - Go directly to specialists
- Predictable costs - Know exactly what you'll pay each month
- Guaranteed renewable - Company cannot cancel your policy as long as you pay premiums
- Travel freedom - Coverage follows you anywhere in the U.S. (and limited foreign coverage)
When to Buy: The Open Enrollment Window
The best time to buy Medigap is during your Medigap Open Enrollment Period:
- Starts the month you turn 65 AND are enrolled in Part B
- Lasts 6 months
- During this window, you have guaranteed issue rights
Guaranteed issue means insurance companies:
- Cannot deny you coverage
- Cannot charge more due to pre-existing conditions
- Must sell you any Medigap plan they offer
After this 6-month window, companies can use medical underwriting. You could be denied coverage or charged higher premiums based on your health history.
What Medigap Doesn't Cover
Medigap policies do NOT cover:
- Prescription drugs (you need a Part D plan)
- Dental, vision, or hearing
- Long-term care
- Private-duty nursing
Medigap vs. Medicare Advantage
You cannot have both Medigap and Medicare Advantage. They're different approaches to Medicare coverage:
- Medigap + Part D: Higher premiums, no network, predictable costs
- Medicare Advantage: Lower/no premiums, network restrictions, out-of-pocket maximum
Compare with Medicare Advantage
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Get Free QuotesFrequently Asked Questions
How much does Medicare Supplement cost?
Premiums vary widely based on your age, location, and the insurance company. Plan G typically ranges from $100 to $300+ per month. Plan N is usually 20-30% less. Premiums generally increase as you age.
Can I switch Medigap plans later?
You can apply to switch plans anytime, but outside your Open Enrollment Period, you'll likely face medical underwriting. Some states have additional guaranteed issue rights. If you're healthy, switching is usually possible; if you have health issues, it may be difficult.
Do I need Medigap if I'm still working at 65?
If you have good employer coverage, you may not need Medigap yet. But be aware: your Medigap Open Enrollment Period starts when you enroll in Part B, regardless of other coverage. Some people delay Part B (and thus their Medigap window) while on employer coverage.
Is Medigap the same as Medicare Advantage?
No, they're completely different. Medigap supplements Original Medicare - you keep Parts A and B and add Medigap on top. Medicare Advantage replaces Original Medicare with a private plan. You cannot have both at the same time.