Medicare Supplement Plans

Medicare Supplement Insurance, also called Medigap, is private insurance designed to help pay some of the out-of-pocket costs left by Original Medicare. In most states, Medigap policies are standardized by plan letter, so a Plan G from one insurer has the same basic standardized benefits as Plan G from another insurer. Premiums can still vary by company, location, pricing method, age and other permitted factors. ^[1]^[2]

How Medicare Supplement works

Medigap works with Original Medicare, not in place of it. You generally need Medicare Part A and Part B to buy a Medigap policy. Medicare pays its share of Medicare-covered services first, and the Medigap policy then pays according to the benefits included in that policy. ^[1]

Medigap is different from Medicare Advantage. A Medicare Advantage plan is another way to receive your Medicare Part A and Part B benefits through a private plan approved by Medicare. A Medigap policy supplements Original Medicare and cannot be used to pay the cost sharing of a Medicare Advantage plan. ^[1]^[3]

What Medigap may help pay

Depending on the standardized plan letter, Medigap may help with costs such as Part A coinsurance and hospital costs, Part B coinsurance or copayments, the first three pints of blood, hospice coinsurance or copayments, skilled nursing facility coinsurance, the Part A deductible, Part B excess charges, and certain foreign-travel emergency costs. The exact combination depends on the plan letter. ^[4]

Medigap generally does not cover long-term care, routine dental care, routine vision care, hearing aids, eyeglasses or private-duty nursing. Medigap policies sold after 2005 do not include prescription drug coverage, so people who want drug coverage with Original Medicare generally consider a separate Medicare Part D plan. ^[3]

Plan G, Plan N and Plan F

Plan G, Plan N and Plan F are among the most frequently compared Medigap options.

Plan G

Plan G covers the standardized Medigap benefits shown by Medicare for Plan G, including Part B excess charges and 80% of foreign-travel emergency costs up to plan limits. It does not cover the Medicare Part B deductible. A high-deductible Plan G option is available in some states. ^[4]

Plan N

Plan N includes many of the same standardized benefits as Plan G, but it does not cover Part B excess charges. For Part B cost sharing, Plan N can require copayments of up to $20 for some office visits and up to $50 for certain emergency-room visits that do not result in an inpatient admission. ^[4]

Plan F

Plan F includes the Part B deductible and Part B excess charges, but it is not available to everyone. People who were newly eligible for Medicare on or after January 1, 2020 cannot buy Plan F. People who were eligible for Medicare before that date may still be able to buy it, subject to availability and enrollment rules. ^[4]^[5]

When to buy Medigap

Your federal Medigap Open Enrollment Period lasts six months and starts the first month you have Medicare Part B and are age 65 or older. During that period, an insurance company cannot deny you a Medigap policy because of pre-existing health problems. This is a one-time Medigap enrollment period; it is not the same as Medicare’s annual fall Open Enrollment Period. ^[1]

Outside your Medigap Open Enrollment Period, an insurer may be allowed to use medical underwriting, charge more, or deny an application unless you have a guaranteed-issue right or another protection. State law may provide additional protections, and rules for people under age 65 vary by state. ^[6]

How Medigap premiums are determined

Medicare does not set a single national premium for Medigap. Premiums vary by insurer, policy, location and other factors. Because the standardized benefits of the same lettered plan are generally the same, it is important to compare both the premium and how the insurer prices the policy over time. ^[2]

The lowest initial premium is not automatically the lowest long-term cost. Ask how premiums are rated, what household or payment discounts may apply, whether rates can increase with age, and how the company’s rate history has changed.

Three states use different standardization

Massachusetts, Minnesota and Wisconsin standardize Medigap differently from the federal lettered-plan structure used in most states. If you live in one of these states, compare the state-specific Medigap options rather than assuming the standard Plan G, N or F structure applies in the same way. ^[1]

How to compare Medicare Supplement policies

When comparing Medigap, start with the plan letter that fits the benefits you want, then compare insurers offering that letter in your area. Review:

Monthly premium
Pricing method and potential future increases
Eligibility and underwriting rules
Household or other permitted discounts
Financial strength and service considerations
Whether a high-deductible version is offered
Whether you also need separate Part D drug coverage

Do not compare Medigap policies only by carrier name. In most states, the standardized benefits for the same letter are the same regardless of insurer; price and company-specific factors are what differ. ^[2]

Get help comparing your options

A licensed Wise Owl Insurance Group agent can help you compare Medicare Supplement options available in your area and explain how Medigap fits with Original Medicare and Part D. Plan availability, eligibility, underwriting and premiums vary by state, insurer and individual circumstances.

This page is educational and does not list every policy available in every area. Always review the insurer’s current outline of coverage and official policy documents before enrolling.

Last reviewed: 2026-09-21

Official sources

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