Medigap Plans: Medicare Supplement Insurance Guide
Key Takeaways
- Medigap fills the "gaps" in Original Medicare — covering deductibles, copays, and coinsurance
- There are 10 standardized plan types (A through N) — benefits are identical across insurers
- Plan G is the most popular — covers everything except the Part B deductible
- Cannot be used with Medicare Advantage — it's one or the other
Table of Contents
What Is Medigap?
Medigap (officially called Medicare Supplement Insurance) is private health insurance designed to work alongside Original Medicare (Parts A & B). It helps cover the out-of-pocket costs that Original Medicare leaves you responsible for — including deductibles, copayments, and coinsurance.
Think of Medigap as a financial safety net. With Original Medicare alone, there is no annual out-of-pocket maximum — meaning your costs could theoretically be unlimited if you have serious health issues. Medigap policies eliminate or significantly reduce that financial risk.
How Medigap Works
You must have Original Medicare (Parts A & B)
Medigap only works with Original Medicare. It cannot be used with Medicare Advantage.
You pay a monthly premium to a private insurer
This is in addition to your Part B premium. Medigap premiums vary by plan type, insurer, age, and location.
Medicare pays its share, then Medigap pays most or all of the rest
When you receive a service, Medicare processes the claim first. Then your Medigap plan pays its share of the remaining costs.
You can see any Medicare-accepting provider nationwide
Medigap plans have no networks. Any provider that accepts Medicare must accept your Medigap plan.
Medigap Plans Compared
Medigap plans are standardized by the federal government. This means Plan G from one company covers the exact same benefits as Plan G from another company — only the price differs. Here's what each plan covers:
| Benefit | A | B | C | D | F | G | K | L | M | N |
|---|---|---|---|---|---|---|---|---|---|---|
| Part A coinsurance/hospital costs | 50% | 75% | ||||||||
| Part B coinsurance/copayment | 50% | 75% | copays | |||||||
| Blood (first 3 pints) | 50% | 75% | ||||||||
| Part A hospice coinsurance | 50% | 75% | ||||||||
| Skilled nursing coinsurance | 50% | 75% | ||||||||
| Part A deductible | 50% | 75% | 50% | |||||||
| Part B deductible | ||||||||||
| Part B excess charges | ||||||||||
| Foreign travel emergency | 80% | 80% | 80% | 80% | 80% | 80% |
Note About Plans C & F
Plans C and F are no longer available to people who became newly eligible for Medicare on or after January 1, 2020. If you were eligible before that date, you may still be able to purchase these plans.
Most Popular Medigap Plans
Plan G
Covers everything Original Medicare doesn't — except the annual Part B deductible ($257 in 2026). After you pay that deductible, you'll have essentially zero out-of-pocket costs for Medicare-covered services.
Avg. Premium: $130–$250/month depending on age and location
Plan N
A cost-effective alternative to Plan G. Covers most gaps but has small copays for office visits ($20) and ER visits ($50, waived if admitted). Does not cover Part B excess charges.
Avg. Premium: $80–$180/month depending on age and location
When to Buy Medigap
The best time to buy a Medigap policy is during your Medigap Open Enrollment Period:
Medigap Open Enrollment Period
Starts the first day of the month you're both 65 or older and enrolled in Part B. Lasts 6 months.
During this period, insurance companies must accept you regardless of health conditions and cannot charge you more due to pre-existing conditions. This is your best guaranteed rate.
After Your Open Enrollment Ends
Insurance companies may use medical underwriting — they can deny you, charge higher rates, or exclude coverage for pre-existing conditions. Don't miss this window.
Medigap vs. Medicare Advantage
This is one of the biggest decisions in Medicare. Here's the key distinction:
| Factor | Medigap + Original Medicare | Medicare Advantage |
|---|---|---|
| Monthly Cost | Higher (Part B + Medigap + Part D) | Lower (many plans $0 premium) |
| Out-of-Pocket Risk | Very low (Medigap covers most gaps) | Moderate (copays until you hit max) |
| Doctor Freedom | Any Medicare provider — nationwide | Network-based (varies by plan type) |
| Extra Benefits | None (no dental, vision, hearing) | Dental, vision, OTC cards, fitness |
| Best For | People who want predictable costs & max flexibility | People who want low premiums & extra benefits |
Need help deciding between Medigap and Medicare Advantage?
A licensed Medicare advisor can compare your options side by side — free, no obligation.
Disclaimer
We are not affiliated with Medicare or any government agency. This content is for informational purposes only. Calling the phone number on this page will connect you with a licensed insurance agent. Medicare has neither reviewed nor endorsed this information.
Got Questions?
Frequently Asked Questions
Medigap (Medicare Supplement Insurance) is private insurance that helps pay for costs that Original Medicare doesn't cover — like copayments, coinsurance, and deductibles. There are 10 standardized plan types (A, B, C, D, F, G, K, L, M, N), each offering different levels of coverage.
No. Medigap only works with Original Medicare (Parts A & B). It is illegal for an insurance company to sell you a Medigap policy if you're enrolled in Medicare Advantage. You must choose one path or the other.
The best time is during your Medigap Open Enrollment Period — the 6 months starting when you're both 65+ and enrolled in Part B. During this window, insurance companies must sell you any Medigap plan they offer, regardless of health conditions, at the standard rate.
Plan G is the most popular Medigap plan for people newly eligible for Medicare. It covers everything except the Part B deductible ($257 in 2026). Plan N is a lower-cost alternative with small copays for some doctor visits and ER visits.
No. No Medigap plan sold today covers prescription drugs. You'll need a standalone Part D plan for drug coverage if you choose Original Medicare + Medigap.
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