What it is
Medigap, also called Medicare Supplement Insurance, is private insurance that may help pay some out-of-pocket costs Original Medicare leaves behind, such as certain copayments, coinsurance and deductibles. It works alongside Original Medicare rather than replacing it.
The plan letters (such as A, B, C, D, F, G, K, L, M and N) are labels for standardized benefit packages. In most states, a plan with a given letter offers the same basic benefits no matter which company sells it. Some states, such as Massachusetts, Minnesota and Wisconsin, use their own standardized formats.
What differs from one company to another is generally the price, the company's service and how premiums are set. Not every letter is sold to every person, and some letters are no longer available to people newly eligible for Medicare. Current availability and costs are best confirmed with Medicare.gov or 1-800-MEDIGAP.
How it’s traditionally been approached
Many people have approached Medigap by first deciding whether they want Original Medicare with a supplement, or a Medicare Advantage plan instead. Both are legitimate choices with real trade-offs. Medigap generally offers broad provider choice and more predictable cost-sharing, while Medicare Advantage often bundles extra benefits and may have network rules and different cost structures.
Within Medigap, people have often compared letters by weighing how much of their cost-sharing they want covered against how much monthly premium they are comfortable with. Some prefer plans that cover more, while others choose plans with lower premiums and more cost-sharing when they use care.
Timing has traditionally mattered, too. Rules about when you can buy a Medigap plan, and whether a company must accept you, can depend on your situation and state. Many people review these rules carefully before making a decision, since they can affect options later.
How the right agent may help
An independent agent who works with Medigap may help you sort through the letters and explain how they relate to your own situation. They may also explain how the rules in your state work and which companies sell plans in your area. A good agent can be a helpful guide, though no outcome is promised.
A conversation with an agent is generally informational. They may ask about your doctors, how often you use care, your budget and your comfort with uncertainty. You can also expect questions about your current coverage, so they can explain how a Medigap plan would fit alongside it.
Helpful questions to ask include: What do the letters I'm considering cover and not cover? How do this company's premiums tend to change over time? Do you work with several companies? How are you paid? Which plans are available to me, and what happens if my health changes? You can confirm current figures with Medicare.gov or 1-800-MEDIGAP.
The bigger picture
Choosing supplemental coverage is partly about numbers and partly about peace of mind. Some people feel calmer knowing their cost-sharing is more predictable, while others prefer to keep premiums lower and accept more variability. Neither mindset is wrong; it's about what fits your life.
Worry about health costs can affect sleep, stress and relationships. Taking time to understand your options, and perhaps involving a trusted family member, may make the decision feel more manageable. If you also want help finding care providers, Providers.plus may be one place to explore.
Keep in mind
- Medigap plan letters describe standardized benefits, but premiums, availability and rules can vary by company, state and year.
- Medigap and Medicare Advantage each have real advantages and drawbacks, so the better fit depends on your needs and preferences.
- Medicare News is an independent directory and is not connected with the U.S. government or the federal Medicare program.
- This page is educational only and is not medical, legal, tax or financial advice. Confirm current details with Medicare.gov or 1-800-MEDIGAP.
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Call 1-800-MEDIGAP →Frequently asked questions
What do Medigap plan letters mean?
Medigap plan letters are labels for standardized sets of benefits that may help pay certain costs Original Medicare doesn't cover. In most states, a given letter offers the same basic benefits regardless of the insurance company. Each letter combines coverage differently, so the letters are a way to compare packages.
Are all Medigap plans with the same letter identical?
In most states, the benefits are the same for plans with the same letter, but price and company service can differ. Massachusetts, Minnesota and Wisconsin use their own standardized systems. Comparing companies is therefore as important as comparing letters.
Which Medigap plan letter is best?
There isn't one best letter, because the right choice depends on your health needs, budget and comfort with cost-sharing. Some people prefer plans that cover more, while others prefer lower premiums with more out-of-pocket exposure. An independent agent may help you compare options for your situation.
Can I buy any Medigap plan letter I want?
Not always. Some letters are not sold to people who became eligible for Medicare after certain changes, and not every company sells every letter in every area. Current availability can be confirmed through Medicare.gov or 1-800-MEDIGAP.
Is Medigap the same as Medicare Advantage?
No. Medigap is a supplement that works alongside Original Medicare, while Medicare Advantage is a different way to receive Medicare benefits through a private plan. Each has trade-offs involving provider choice, costs and extra benefits, so it helps to compare them fairly.
Where can I find current Medigap costs and rules?
Current premiums and rules change over time, so check Medicare.gov or call 1-800-MEDIGAP for up-to-date information. Medicare News does not quote prices or enrollment dates. We are an independent directory and not affiliated with the government.
Educational resource. Medicare News shares general information and connects people with independent agents. It is not professional advice. Talk with a qualified professional about your own situation.