A Medigap Plan Covers What Original Medicare Leaves You Paying

A Medigap plan (also called Medigap insurance or supplemental insurance) is a policy sold by private insurance companies that pays some or all of the costs that Original Medicare does not cover. Original Medicare — Part A and Part B — pays a large share of your hospital and doctor bills, but leaves you responsible for deductibles, copayments, and coinsurance. Medigap steps in to cover those out-of-pocket costs.

For example, if you go to the hospital, Medicare Part A covers most of the bill but you pay a deductible. If you see a doctor, Medicare Part B covers 80 percent of the approved amount and you pay 20 percent coinsurance. A Medigap plan can pay those amounts so you do not have to.

Medigap is different from Medicare Advantage (Part C), which is an alternative way to receive Medicare benefits through a private plan. With Medigap, you keep Original Medicare and add a supplemental policy on top.

Key Takeaways

  • Medigap plans are sold by private insurance companies and cover deductibles, copayments, and coinsurance that Original Medicare does not pay.
  • There are ten standardized Medigap plans (labeled A through N), and the same plan letter covers the same benefits no matter which company sells it.
  • You can only enroll in Medigap during specific windows: within six months of turning 65 and enrolling in Medicare Part B, or during the annual open enrollment period.
  • Medigap premiums vary by insurance company, your age, and your location, and you pay the premium directly to the insurance company each month.
  • You must have Original Medicare Part A and Part B to buy Medigap; you cannot use Medigap with Medicare Advantage.

The Ten Standardized Medigap Plans and What Each Covers

The federal government sets ten standardized Medigap plans, labeled A through N. Each plan letter covers a fixed set of benefits, so Plan G sold by Company X covers exactly the same things as Plan G sold by Company Y. The difference is only the premium price.

The most common plans are G, N, and F (though Plan F is no longer sold to people new to Medicare). Plan G covers most costs except the Part B deductible. Plan N covers most costs but leaves you paying some copayments and coinsurance. Plan A is the most basic and least expensive but covers fewer costs. Plans D, H, I, J, and K are rarely sold today.

You can view a chart showing what each plan covers on the Medicare.gov website. The chart compares all ten plans side by side so you can see which costs each one pays.

When You Can Enroll in Medigap

The best time to enroll in Medigap is within six months of turning 65 and enrolling in Medicare Part B. During this window — called the Medigap open enrollment period — insurance companies must sell you any plan you want at the lowest price, regardless of your health. This is the only time you have may provide access to any plan without medical underwriting.

If you miss this window, you can still buy Medigap during the annual open enrollment period (October 15 to December 7 each year), but outside your initial six-month window, insurance companies can deny you, charge you more, or exclude pre-existing conditions. Some states have additional protections, but federal law does not require companies to sell to you if you wait.

You can also enroll in Medigap if you leave Medicare Advantage and return to Original Medicare, though the rules vary by state and timing.

How Much Medigap Costs and What Affects the Price

Medigap premiums vary widely depending on which plan you choose, which insurance company sells it, your age, and your location. A Plan G might cost $120 per month with one company and $180 with another in the same city. The same plan in a different state or county can cost significantly more or less.

Insurance companies use three main methods to set premiums: community-rated (everyone in your area pays the same), age-rated (younger people pay less), and issue-age-rated (your premium is based on your age when you first buy the plan and does not increase as you age). You pay the premium directly to the insurance company by check, bank draft, or credit card, usually monthly.

You can compare premiums by entering your zip code on Medicare.gov or by calling insurance companies directly. Comparing is worth the time because the same plan can cost thousands of dollars more per year with one company than another.

Medigap Does Not Cover Everything

Even with a Medigap plan, you still pay for some services. Medigap does not cover dental work, vision care, hearing aids, long-term care, or prescription drugs. You would need separate coverage for those — dental and vision through a private plan, prescription drugs through Medicare Part D, and long-term care through a long-term care insurance policy or by paying out of pocket.

Medigap also does not cover services that Medicare itself does not cover, such as cosmetic surgery or most routine foot care. If Medicare does not pay for it, Medigap will not either.

How to Compare and Choose a Medigap Plan

Start by deciding how much out-of-pocket cost you can afford. If you want the lowest monthly premium, Plan A or Plan N costs less but leaves you paying some copayments. If you want the lowest out-of-pocket costs when you use care, Plan G or Plan F (if you are may be able to access) costs more per month but covers more when you see a doctor or go to the hospital.

Next, get premium quotes from at least three insurance companies for the plans you are considering. You can call companies directly, use Medicare.gov's plan comparison tool, or work with a licensed insurance broker who represents multiple companies. A broker does not charge you a fee — they are paid by the insurance company — but make sure they are licensed in your state.

Check whether the insurance company has a good reputation for paying claims and handling customer service. You can read reviews on the National Association of Insurance Commissioners (NAIC) website or ask your doctor's office which companies they work with most smoothly.

Switching Medigap Plans or Insurance Companies

You can switch to a different Medigap plan or a different insurance company at any time, but the rules change depending on whether you are still in your initial six-month open enrollment window. During that window, you can switch without medical underwriting. After that window closes, an insurance company can deny you or charge you more if you have health problems.

Some states have additional protections that allow you to switch plans once per year without medical underwriting, even after your initial window. Check your state's insurance commissioner's office to see what protections explore where you live.

If you are switching companies but keeping the same plan letter, the new company must cover your pre-existing conditions when ready. If you are switching to a different plan letter after your open enrollment window, the new company can exclude pre-existing conditions for up to six months.

Frequently Asked Questions

Can I have both Medigap and Medicare Advantage at the same time?

No. You must choose one or the other. If you have Medicare Advantage, you cannot buy Medigap. If you have Medigap, you cannot enroll in Medicare Advantage. You can switch between them, but only during specific enrollment periods and with potential waiting periods for Medigap if you switch back.

Do I need Medigap if I have Medicare Advantage?

No. Medicare Advantage includes coverage for the costs that Original Medicare does not pay, so Medigap would be redundant and is not allowed. Medicare Advantage plans have their own deductibles and copayments, which may be higher or lower than Original Medicare's.

What happens to my Medigap plan if I move to a different state?

Your Medigap plan stays active, but your premium may change because rates vary by location. Contact your insurance company to find out your new rate. You can also shop for a new plan with a different company in your new state, though you may face medical underwriting if you are outside your initial enrollment window.

Can I get Medigap if I have a pre-existing condition?

Yes, if you enroll within six months of turning 65 and enrolling in Medicare Part B. During that window, insurance companies cannot deny you or charge you more because of health problems. If you wait past that window, companies can deny you or exclude pre-existing conditions, depending on your state's rules.

Does Medigap cover prescription drugs?

No. You need a separate Medicare Part D prescription drug plan for that coverage. You can enroll in Part D when you first turn 65, and you can change plans every year during the annual open enrollment period.