Medicare Supplement policies are sold by private insurance companies, not by Medicare itself

Medicare Supplement insurance (also called Medigap) is sold only by private insurance carriers — companies like UnitedHealthcare, Aetna, Cigna, Humana, and Blue Cross Blue Shield. Medicare does not sell these policies. The federal government sets the rules for what each Medigap plan must cover, but the insurance companies decide whether to offer those plans in your area and how much to charge.

You buy Medigap directly from the insurance company or through an insurance agent or broker who represents multiple companies. There is no central government marketplace for Medigap the way there is for Medicare Advantage plans. Instead, you contact insurers in your state one by one, or work with an agent who can show you what each company offers.

The price and availability of the same Medigap plan varies significantly by company and by state. Plan G from one insurer might cost $120 a month while Plan G from another costs $180 a month for the same coverage. Not every company sells every plan type in every state, so you may have fewer options than you expect.

Key Takeaways

  • Private insurance companies sell Medigap policies; Medicare itself does not offer them.
  • The same Medigap plan costs different amounts depending on which insurance company sells it and what state you live in.
  • You can buy directly from an insurance company, through an independent agent, or through a broker who works with multiple insurers.
  • Your best enrollment window is within 63 days of turning 65 or first enrolling in Medicare Part B, when insurers cannot deny you or charge more based on health history.

The major insurance companies that sell Medigap in most states

The largest Medigap sellers nationwide include UnitedHealthcare, Aetna, Cigna, Humana, Blue Cross Blue Shield (which operates under different names in different states), AARP/UnitedHealthcare, and Mutual of Omaha. Smaller regional companies also sell Medigap in specific states. No single company sells in all 50 states, and each company decides which plan types to offer in each state.

Some insurers focus on certain regions. For example, AARP-branded Medigap is sold through UnitedHealthcare and is available in most states, but not all. Mutual of Omaha has strong presence in the Midwest and South. Blue Cross plans operate under state-specific names — Blue Cross Blue Shield of Illinois, Blue Cross of California — so you may not recognize the company name even though it is part of the national Blue Cross network.

The company you choose matters because the same plan type from different companies will have different monthly costs, different customer service reputations, and different networks of doctors (though Medigap itself does not restrict which doctors you see — that is a Medicare Advantage feature).

How to find which companies sell Medigap in your state

The Medicare.gov website has a tool called the Medigap Plan Finder that shows you which insurance companies sell which plans in your ZIP code. Go to Medicare.gov, select "Find Care Providers and Suppliers," then look for the Medigap Plan Finder. Enter your state and ZIP code, and the tool will list every company selling Medigap near you, the plan types each offers, and the monthly premium for each.

You can also call 1-800-MEDICARE (1-800-633-4227) and ask which companies sell Medigap in your area. The representative can give you phone numbers and websites for insurers to contact directly. Many state health insurance information programs (called SHIP in most states) also have counselors who can walk you through the options and help you compare prices.

Insurance agents and brokers can also show you what is available. Some work for one company only; others represent multiple insurers and can show you side-by-side comparisons. If you work with an agent, confirm they are licensed in your state and ask whether they earn commission (most do) so you understand their incentive.

When you have the strongest protection when buying Medigap

The best time to buy Medigap is within 63 days of turning 65 or first enrolling in Medicare Part B. During this window, called the Medigap Open Enrollment Period, insurance companies must sell you any plan they offer in your state, and they cannot charge you more or refuse you based on your health history or pre-existing conditions. This protection is federal law.

If you miss this 63-day window, insurers can deny you coverage, charge you higher premiums, or exclude pre-existing conditions from coverage — depending on your state's rules. Some states offer additional protections, but they vary widely. Once you are outside the enrollment period, buying Medigap becomes much harder and more expensive.

If you are already on Medicare and did not buy Medigap during your initial enrollment period, you may still have options. Some states have rules that let you buy Medigap later under certain circumstances (such as losing employer coverage). Contact your state's SHIP program to learn what applies to you.

The difference between buying directly and using an agent

When you buy directly from an insurance company's website or by phone, you work only with that company. You see only their plans and prices. You are responsible for comparing their offerings to competitors on your own. Direct purchase is straightforward if you already know which company and plan you want.

An independent agent or broker represents multiple insurance companies and can show you what each offers in your area. They can compare prices and coverage side by side, which saves time if you are comparing many options. Agents earn commission from the insurance company when you buy, but this does not cost you extra — the premium is the same whether you buy direct or through an agent.

A captive agent works for one insurance company only and can show you only that company's plans. They may be helpful if you already prefer that company, but they cannot show you alternatives. Always ask an agent upfront which companies they represent.

What information you need before contacting an insurance company

Have your Medicare card handy when you call or visit a Medigap seller. You will need your Medicare number, your date of birth, and your state of residence. If you are comparing multiple companies, write down the plan letter (A, B, D, G, K, L, M, or N) you are interested in, because the same letter means the same coverage no matter which company sells it — only the price changes.

Ask each company for a written quote that shows the monthly premium, what the plan covers, what it does not cover, and any waiting periods for pre-existing conditions. Do not rely on phone quotes alone. Written quotes let you compare apples to apples across multiple companies.

Also ask whether the company offers discounts for paying annually instead of monthly, or for setting up automatic payments. Some insurers offer modest savings for these choices.

Frequently Asked Questions

Can I buy Medigap from Medicare directly?

No. Medicare sets the rules for what Medigap plans must cover, but only private insurance companies sell the actual policies. You must contact an insurance company, agent, or broker to purchase Medigap.

Do all insurance companies sell all Medigap plan types?

No. Each company decides which plan letters (A through N) to offer in each state. One company might sell Plan G and Plan N in your state but not Plan D. You may need to contact multiple companies to find the plan you want at a price you can afford.

What if I buy Medigap and then move to a different state?

Your Medigap policy may not be valid in your new state, or the company may not sell that plan type there. Contact your insurance company before you move to find out whether your coverage continues. You may need to switch to a different plan or company after you relocate.

Is there a difference between Medigap sold by AARP and Medigap sold by other companies?

AARP-branded Medigap is actually sold by UnitedHealthcare; AARP does not sell insurance itself. The coverage is the same as any other Medigap plan with the same letter, but the price may differ. AARP membership is not required to buy AARP-branded Medigap, though AARP may advertise it primarily to members.

Can an insurance company refuse to sell me Medigap if I have health problems?

Not during your Medigap Open Enrollment Period (the 63 days after you turn 65 or first enroll in Part B). During this window, companies must sell you any plan they offer. Outside this window, they can refuse you or charge more based on health history, depending on your state's rules.