If you are new to Medicare, you have probably discovered an uncomfortable truth: Original Medicare does not cover everything. Between deductibles, coinsurance, and copayments, the out-of-pocket costs can add up fast — especially if you are managing ongoing health conditions or facing an unexpected hospital stay.
That is exactly where Medicare Supplement plans — commonly known as Medigap — come in. These private insurance policies are designed to fill the financial gaps that Original Medicare leaves behind, giving you more predictable healthcare costs and greater peace of mind.
In this guide, we will walk you through everything you need to know about medicare supplement plans: what they are, how they work alongside Original Medicare, who is eligible, and how to choose the right plan for your needs.
What Is Medigap (Medicare Supplement Insurance)?
Medigap is supplemental health insurance sold by private companies that helps pay for costs that Original Medicare (Part A and Part B) does not fully cover. These include:
- Copayments — your share of the cost for a doctor visit or service
- Coinsurance — the percentage you owe after Medicare pays its part (typically 20% under Part B)
- Deductibles — the amount you pay before Medicare starts covering costs
Important: Medigap policies do not include prescription drug coverage. For that, you will need a separate Medicare Part D plan.
How Does Medigap Work With Original Medicare?
Think of Medigap as a financial safety net layered on top of Original Medicare. Here is how the process works when you receive medical care:
- You visit a doctor or hospital that accepts Medicare.
- Medicare Part A or Part B pays its share of the approved amount.
- Your Medigap policy kicks in and pays some or all of the remaining costs — depending on which plan you have.
Because Medigap plans are standardized by the federal government, a Plan G from one insurance company covers exactly the same benefits as a Plan G from another. The only differences between carriers are the premium price, customer service, and financial stability of the company.
This standardization makes comparison shopping straightforward — you are comparing price, not benefits.
Who Is Eligible for a Medigap Plan?
To enroll in a Medigap plan, you must:
- Be enrolled in both Medicare Part A and Part B
- Live in the service area of the plan you are applying for
The Medigap Open Enrollment Period
Your Medigap Open Enrollment Period is the single most important window for securing coverage. It lasts 6 months, starting the month you turn 65 and are enrolled in Medicare Part B.
During this period:
- Insurance companies cannot deny you coverage for any reason
- They cannot charge you more due to pre-existing health conditions
- You have guaranteed issue rights — meaning you can enroll in any Medigap plan available in your state
If you miss this window, insurers can use medical underwriting to decide whether to sell you a policy and how much to charge. Translation: it gets more expensive and harder to qualify. Do not let this deadline slip by.
What Do Medigap Plans Cover? A Comparison Chart
There are 10 standardized Medigap plans, each labeled with a letter: A, B, C, D, F, G, K, L, M, and N. Plans C and F are no longer available to people who became eligible for Medicare on or after January 1, 2020.
| Benefit | A | B | C* | D | F* | G | K | L | M | N |
|---|---|---|---|---|---|---|---|---|---|---|
| Part A Coinsurance | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Part B Coinsurance | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | ✓** |
| Blood (First 3 Pints) | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | ✓ |
| Part A Hospice | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | ✓ |
| Skilled Nursing | ✗ | ✗ | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | ✓ |
| Part A Deductible | ✗ | ✓ | ✓ | ✓ | ✓ | ✓ | 50% | 75% | 50% | ✓ |
| Part B Deductible | ✗ | ✗ | ✓ | ✗ | ✓ | ✗ | ✗ | ✗ | ✗ | ✗ |
| Part B Excess Charges | ✗ | ✗ | ✗ | ✗ | ✓ | ✓ | ✗ | ✗ | ✗ | ✗ |
| Foreign Travel Emergency | ✗ | ✗ | 80% | 80% | 80% | 80% | ✗ | ✗ | 80% | 80% |
*Plans C and F are only available to those who became Medicare-eligible before January 1, 2020.
**Plan N pays 100% of Part B coinsurance except up to $20 for office visits and up to $50 for ER visits that do not result in admission.
Which Medigap Plan Is Most Popular?
Plan G — Maximum Coverage
Medigap Plan G is the most comprehensive plan available to new Medicare beneficiaries. It covers everything except the annual Part B deductible ($240 in 2025). For people who want the most predictable costs with virtually no surprise bills, Plan G is the gold standard.
Plan N — Lower Premiums, Small Copays
Medigap Plan N offers slightly less coverage in exchange for lower monthly premiums. You will pay small copays — up to $20 for office visits and up to $50 for ER visits that do not result in admission. Plan N also does not cover Part B excess charges. For healthy individuals who do not visit the doctor frequently, Plan N can save hundreds per year.
Medigap vs. Medicare Advantage
It is important to understand that Medigap and Medicare Advantage (Part C) are two different paths:
- Medigap works with Original Medicare — you keep Parts A and B and add a supplement on top
- Medicare Advantage replaces Original Medicare — you get Part A and B coverage through a private insurer, often with added benefits like dental and vision
You cannot have both a Medigap plan and a Medicare Advantage plan at the same time.
Frequently Asked Questions
Can I buy Medigap if I am under 65?
It depends on your state. Some states require insurers to sell Medigap to people under 65 who are on Medicare due to disability. Check your state rules or call us at 1-888-781-6026 for guidance.
Does Medigap cover prescription drugs?
No. You will need a separate Medicare Part D plan for prescription drug coverage.
Can I switch Medigap plans later?
You can apply to switch anytime, but outside your Open Enrollment Period, you may face medical underwriting. Some states offer additional protections — we can help you understand your options.
Is Medigap worth the cost?
For many seniors, absolutely. A single hospital stay under Original Medicare alone can cost thousands in deductibles and coinsurance. Medigap turns those unpredictable costs into a manageable monthly premium.
Ready to Find the Right Medicare Supplement Plan?
Choosing a Medigap plan does not have to be overwhelming. At eMedicareGuide.com, our licensed agents help you compare plans and rates from top carriers — at no cost to you.
Call 1-888-781-6026 for a free, no-obligation consultation
Or visit eMedicareGuide.com to compare Medicare Supplement plans and get a personalized quote today.