Medicare Supplement (Medigap) Plans, Explained

What is a Medicare Supplement plan?

Original Medicare pays a lot of your care. It does not pay all of it. You still owe deductibles, copays, and coinsurance. Some of these costs have no cap at all.

A Medicare Supplement plan helps pay those leftover costs. People also call it a Medigap plan. Private insurance companies sell these plans. The plan works with Original Medicare. It does not replace it.

You must have Medicare Part A and Part B to buy a Medigap plan. When you get care, Medicare pays its share first. Then your Medigap plan pays its share. What is left is what you owe.

A Medigap plan covers one person. If you and your spouse both want one, each of you needs your own plan.

Once you buy a plan, you can keep it for life. You just need to pay your premium. A company cannot drop you if your health gets worse.

The plan letters: A, B, C, D, F, G, K, L, M, and N

Medigap plans come in 10 types. Each type has a letter. The federal government sets what each letter must cover. This is the law in most states.

Here is the key point. A Plan G from one company covers the same things as a Plan G from any other company. The benefits are the same. Only two things differ: the price, and the company itself.

So when you shop, you pick the letter first. Then you compare prices for that same letter across companies. No company has to sell every letter. But if a company sells any Medigap plan at all, it must sell Plan A.

A few notes on the chart:

• Plan N pays all of the Part B coinsurance. But you pay a copay of up to $20 for some office visits. You also pay up to $50 for an emergency room visit if you are not admitted to the hospital.
• Plans K and L pay less of each bill. Plan K pays 50%. Plan L pays 75%. But these two plans cap what you spend each year. In 2026, the cap is $8,000 for Plan K and $4,000 for Plan L. Once you hit the cap and meet your Part B deductible, the plan pays 100% of covered costs for the rest of the year.
• Plans F and G also come in a high-deductible form in some states. With that form, you pay the first $2,950 of your Medicare costs in 2026 before the plan pays anything.

Plans C and F: closed if you became eligible in 2020 or later

Plans C and F pay the Part B deductible. Federal law ended that for new buyers. If you first became eligible for Medicare on or after January 1, 2020, you cannot buy Plan C or Plan F.

Were you eligible before 2020? Then you can still buy these plans. And if you already have one, you can keep it.

What happened to Plans E, H, I, and J?

You may still hear about these letters. They were retired in 2010. No one can buy them now. If you kept one from before 2010, it still works as it did.

Medigap does not cover prescription drugs

This part matters. Medigap plans sold since 2006 do not include drug coverage. A Medigap plan will not pay for your prescriptions.

If you want drug coverage, you need a separate Medicare Part D plan. Part D is its own plan, with its own premium. Most people with a Medigap plan buy a Part D plan too.

Read more: Medications and drug coverage

The big choice: Medigap or Medicare Advantage?

Most people pick one of two paths.

Path 1: Original Medicare plus a Medigap plan. You keep Part A and Part B. Your Medigap plan fills the gaps. You can see any doctor in the U.S. who takes Medicare. There is no plan network. You add a Part D plan for drugs. You pay more each month in premiums, but far less when you get care.

Path 2: A Medicare Advantage plan (Part C). One private plan provides your Part A and Part B care. Most of these plans include drug coverage too. You pay less each month, but you use the plan's network, and you pay copays as you get care.

You cannot have both at the same time. A Medigap plan does not work with a Medicare Advantage plan. In fact, it is illegal for a company to sell you a Medigap plan if you are in a Medicare Advantage plan.

Read more: Medicare Advantage plans

When to buy: your 6-month open enrollment window

The best time to buy a Medigap plan is when the law protects you. That time is your Medigap Open Enrollment Period. It lasts 6 months. It starts the month you are 65 or older and you sign up for Part B.

In this window, a company must sell you any plan it offers. It cannot say no due to your health. It cannot charge you more due to your health. It cannot make you wait for coverage of a health problem you already have.

After this window ends, the rules change. In most states, a company can look at your health. It can charge you more. It can turn you down. There are some exceptions, called guaranteed issue rights. See the next section.

Do not let this window slip by if you can help it. It does not come back.

Guaranteed issue rights

In some cases, the law gives you a second chance. These are called guaranteed issue rights. With these rights, a company cannot turn you down or charge you more for your health.

Common cases include:

• Your Medicare Advantage plan leaves Medicare or stops serving your area.
• You lose group health coverage from a job or a union that paid after Medicare.
• You tried a Medicare Advantage plan for the first time and leave it within the first year.
• Your Medigap company goes bankrupt, or the company misled you.

In most cases, you must apply within 63 days after your old coverage ends. Do not wait. If you think one of these cases fits you, ask your State Health Insurance Assistance Program for free help.

How companies set the price: three ways

Companies charge very different prices for the same letter. They also raise prices in different ways. Each company uses one of three methods to set your price based on age:

• Community-rated. Everyone pays the same price, no matter their age. Your price does not go up just because you get older. It can still go up over time for other reasons, like rising health costs.
• Issue-age-rated. Your price is based on the age you are when you buy. You pay less if you buy at 65 than if you buy at 75. Your price does not go up just because you get older.
• Attained-age-rated. Your price is based on your age now. It starts low and goes up as you get older. This is the most common method.

Ask which method a company uses before you buy. A low price at 65 can cost much more by age 80 if the price climbs with age.

Three states do it differently

Massachusetts, Minnesota, and Wisconsin do not use these letters. Each of these states has its own plan designs and its own rules. If you live in one of these states, the chart above does not apply to you. Check your state's plans instead.

Companies that sell Medigap plans

Many well-known companies sell Medigap plans. The list below names major national sellers. Not every company sells in every state. And not every company sells every letter. What you can buy depends on where you live.

Premium prices change often, and they vary a lot by state, age, and plan letter. We will add price ranges from Medicare.gov's own plan search tool in a later update. For now, use the free tool at Medicare.gov to see the plans and prices in your ZIP code.

Please read this before you rely on this page

Care and Living Guide is not connected with or endorsed by the United States government or the federal Medicare program.

Coverage, prices, and plan details change. Companies can change what they offer at any time. Always check with the insurance company directly to confirm what a plan covers and what it costs before you buy. You can also get free, local help from your State Health Insurance Assistance Program.