Medicare Supplement Insurance (Medigap)

Medicare Supplement Insurance, also called Medigap, is private insurance designed to work with Original Medicare (Part A and Part B). It can help pay some of the out-of-pocket costs that Original Medicare doesn't pay, such as certain deductibles, copayments, and coinsurance.

Medigap plans are standardized in most states and identified by letters, such as Plans A, B, D, G, K, L, M, and N. Plans C and F remain available only to certain people who were eligible for Medicare before January 1, 2020.

Because plans are standardized, the basic benefits of a particular lettered plan are generally the same regardless of the insurance company offering it. However, premiums can vary significantly between insurance companies, and not every company offers every plan.

Your Medigap Open Enrollment Period

One of the best times to purchase a Medicare Supplement policy is during your six-month Medigap Open Enrollment Period.

This one-time period begins the first month you're 65 or older and enrolled in Medicare Part B. During this period, you can purchase any Medigap policy sold in your state, and an insurance company cannot deny you coverage or charge you more because of your health conditions.

In certain circumstances, a Medigap insurer may impose a waiting period of up to six months for coverage related to a pre-existing condition. However, prior creditable health coverage may reduce or eliminate that waiting period. Original Medicare will continue covering Medicare-covered services during any applicable Medigap waiting period.

Guaranteed Issue Rights

There are also certain situations when you may have a Guaranteed Issue Right to purchase a Medigap policy outside your initial Medigap Open Enrollment Period.

For example, certain rights may apply when you lose qualifying coverage or, under specific circumstances, leave a Medicare Advantage plan and return to Original Medicare. The plans available under a guaranteed issue right and the time allowed to apply depend on your particular situation.

Popular Medicare Supplement Options

Plan G
Plan G provides extensive coverage for many of the out-of-pocket costs associated with Original Medicare. You remain responsible for the annual Medicare Part B deductible. Plan G also covers Part B excess charges.

Plan N
Plan N can offer a lower-premium alternative to Plan G. It covers 100% of the Part B coinsurance, but you may have copayments of up to $20 for certain office visits and up to $50 for certain emergency room visits that don't result in an inpatient admission. Plan N does not cover Part B excess charges.

Plan F
Plan F provides extensive coverage, including the Medicare Part B deductible. However, you generally cannot purchase Plan F if you became newly eligible for Medicare on or after January 1, 2020.

Plans K & L
These plans use greater cost sharing but provide annual out-of-pocket protection for covered services. For 2026, the out-of-pocket limit is $8,000 for Plan K and $4,000 for Plan L. After you meet the applicable annual limit and the yearly Part B deductible, the Medigap policy pays 100% of covered services for the remainder of the calendar year.

Can I Change Medicare Supplement Plans Later?

Possibly—but don't assume you can change plans whenever you want.

After your six-month Medigap Open Enrollment Period ends, federal law generally does not guarantee that an insurance company must accept you for another Medigap policy unless you qualify for a specific Guaranteed Issue Right. Depending on your state and circumstances, you may have to answer medical questions, go through underwriting, pay a higher premium, or your application could be declined. Some states provide additional protections.

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Choosing the Right Medicare Supplement Plan

Choosing a Medicare Supplement plan isn't only about finding the lowest monthly premium. Consider your healthcare needs, budget, expected out-of-pocket costs, travel needs, plan benefits, and the insurance company's premium.

Because several insurance companies may offer the exact same standardized Medigap plan at different premiums, comparing companies can be just as important as selecting the plan letter.

Let us help you compare Medicare Supplement options and understand the differences so you can make an informed decision about your Medicare coverage.

Medicare Supplement plans are not Medicare Advantage plans and do not include prescription drug coverage. If you need prescription drug coverage with Original Medicare, you may need to enroll in a separate Medicare Part D plan.