Medigap is private insurance that covers costs Medicare leaves you responsible for

Medigap (also called Supplemental Insurance) is a policy you buy from a private insurance company to pay for the gaps in Original Medicare coverage. Original Medicare covers a lot, but not everything — you still owe deductibles, copayments, and coinsurance. Medigap picks up those out-of-pocket costs so you are not caught with a large bill after a doctor visit or hospital stay.

You can only buy Medigap if you are already enrolled in Original Medicare (Parts A and B). If you have a Medicare Advantage plan instead, you cannot use Medigap — those plans work differently and have their own cost structure.

The federal government sets what each Medigap plan covers, so Plan G from one insurance company covers the same things as Plan G from another. The price varies by company and by where you live, but the benefits do not. This means you can compare plans side by side and focus on finding the lowest price for the coverage you want.

Key Takeaways

  • Medigap covers deductibles, copayments, and coinsurance that Original Medicare does not pay, reducing your out-of-pocket costs.
  • You must have Original Medicare (Parts A and B) to buy Medigap; you cannot combine it with Medicare Advantage plans.
  • The federal government sets what each plan covers, so Plan G is the same everywhere — only the price changes by company and location.
  • You have a six-month window after you turn 65 and enroll in Medicare Part B to buy Medigap without being denied or charged more for pre-existing conditions.
  • Plans are labeled A through N, and Plan G is the most common choice for people newly turning 65 because it covers nearly all out-of-pocket costs.

The 10 Medigap plans and what each one covers

There are 10 standardized Medigap plans, labeled A through N. Each plan covers a different combination of costs. The most comprehensive plans cover almost everything Medicare does not; the basic plans cover less and cost less per month.

Plan G is the most popular choice for people newly turning 65. It covers the Part B deductible, copayments, coinsurance, and the cost of blood transfusions. The main thing it does not cover is the Part A hospital deductible (which is $1,676 in 2024, though this amount changes yearly). Plan G costs more per month than Plan N, but many people find the broader coverage worth it.

Plan N is less expensive than Plan G but requires you to pay a copayment at the doctor's office (usually $20) and a copayment for emergency room visits. It also does not cover the Part A hospital deductible. Plan N is a good fit if you do not go to the doctor often and want to keep your monthly premium lower.

Plan A is the most basic and the cheapest. It covers copayments and coinsurance but not deductibles. Plan D is similar but includes coverage for the Part A deductible. Plans B, C, F, and K offer different combinations of deductible and copayment coverage at different price points. Plans H, I, J, L, and M are no longer sold to new customers but may still be held by people who bought them years ago.

Your choice depends on how often you see doctors, whether you want to minimize monthly costs or out-of-pocket costs at the time of care, and your budget. A financial counselor at your local Area Agency on Aging can walk through the trade-offs with you.

When you can buy Medigap without being turned down

Insurance companies can refuse to sell you Medigap or charge you more if you have a pre-existing condition — but only outside a specific window. When you turn 65 and enroll in Medicare Part B, you have a six-month open enrollment period during which insurance companies must sell you any Medigap plan at the standard rate. They cannot deny you or charge you more because of your health history.

This window is crucial. If you wait to buy Medigap after those six months are up, an insurance company can look at your medical record and either refuse to sell you a policy or charge you a higher premium. Some states have additional protections that extend this window or limit how much companies can charge, but the federal six-month period is the one you can count on everywhere.

The six-month clock starts the month you turn 65 and enroll in Part B. Mark your calendar and contact insurance companies during this time. If you miss the window, you can still buy Medigap later, but you may face denial or a higher price.

How Medigap premiums are priced

Medigap premiums vary widely depending on where you live, which insurance company you choose, and how old you are when you buy the plan. A Plan G policy might cost $120 per month in one state and $200 in another. The same plan from two different companies in the same city can differ by $50 or more per month.

Insurance companies use three main methods to set prices. Community-rated plans charge everyone in your area the same price regardless of age. Issue-age-rated plans charge based on how old you are when you buy the policy — the younger you are, the lower your rate stays for life. Attained-age-rated plans start lower but increase as you get older, so your premium goes up each year.

Because prices vary so much, it is worth getting quotes from several companies. Your state insurance commissioner's office and the Medicare.gov Plan Finder tool both let you compare plans and prices in your area. Spending an hour comparing can save you hundreds of dollars per year.

Medigap does not cover everything

Medigap covers the gaps in Original Medicare, but it does not cover everything. It does not pay for dental care, vision care, hearing aids, or long-term care (nursing home or in-home care). It does not cover prescription drugs — you need a separate Part D prescription drug plan for that.

If you need dental or vision coverage, you can buy a standalone dental or vision plan, though these are usually limited and do not cover major work. Long-term care is not covered by Medicare or Medigap at all; you would need a separate long-term care insurance policy, which is expensive and must be bought before you need care.

Read the plan documents carefully before you buy. The insurance company must give you a document called the "Outline of Coverage" that lists exactly what is and is not covered. Do not assume — ask the company directly if you are unsure whether a specific service is covered.

How to compare and buy Medigap

Start by deciding which plan type fits your needs and budget. If you want the broadest coverage and can afford a higher monthly premium, Plan G is the standard choice. If you want to keep your monthly cost down, Plan N or Plan A might work better.

Next, get quotes from at least three insurance companies in your state. You can call companies directly, use the Medicare.gov Plan Finder, or contact your State Health Insurance information Program (SHIP). SHIP is a free counseling service run by your state — counselors can walk you through the plans and help you compare prices. Find your state's SHIP by calling 1-800-MEDICARE or visiting shiptalk.org.

Once you have chosen a plan and a company, you can buy online, by phone, or by mail. The insurance company will send you a policy document and a member ID card. Your coverage usually starts on the first day of the month after the company receives your payment.

What happens if you switch Medigap plans

You can switch from one Medigap plan to another at any time, but the rules change depending on when you switch. If you switch within the first 12 months after you buy your first Medigap plan, most states let you switch without medical underwriting — meaning the company cannot deny you or charge you more for health reasons. After 12 months, switching becomes harder and the company can review your health history.

Some states have additional protections. A few states let you switch plans once per year without underwriting. Others have "birthday rules" that let you switch during a certain month each year. Check with your state insurance commissioner's office or SHIP to learn what protections explore where you live.

If you are thinking about switching, do it during your protected window if possible. Compare the new plan's premium to your current one — sometimes the savings are worth switching, sometimes they are not. Remember that you cannot switch to a plan that is less comprehensive than the one you have without medical underwriting, even within the protected window.

Frequently Asked Questions

Can I have both Medigap and Medicare Advantage?

No. You must choose either Original Medicare with Medigap or Medicare Advantage. If you have Medicare Advantage and want to switch to Original Medicare with Medigap, you have a limited window to do so without being denied coverage. Contact your State Health Insurance information Program for the exact rules in your state.

Does Medigap cover prescription drugs?

No. Medigap covers out-of-pocket costs for doctor visits and hospital care, but not medications. You need a separate Medicare Part D prescription drug plan. You can enroll in Part D when you first turn 65, or during the annual open enrollment period in October and November.

What if I miss the six-month open enrollment window?

You can still buy Medigap after the window closes, but the insurance company can deny you or charge you more based on your health. Some states have additional protections that extend the window or limit price increases. Contact your state insurance commissioner's office to learn what applies to you.

Will my Medigap premium go up every year?

Yes, most Medigap premiums increase over time, though the amount and frequency vary by plan type and insurance company. Issue-age-rated plans have smaller increases because your rate is locked in at the age you buy. Attained-age-rated plans increase more as you get older. Ask the insurance company which method they use before you buy.

Can I use my Medigap plan outside the United States?

Most Medigap plans cover emergency care outside the U.S., but coverage is limited and you usually have to pay upfront and file for reimbursement later. If you travel internationally often, ask your insurance company for details about what is covered and what is not.