Can I Switch from Medicare Advantage to Medigap? Guaranteed Issue Rights Explained

Medigap works only with Original Medicare, and Medicare.gov says it is illegal for anyone to sell you a Medigap policy while you have a Medicare Advantage plan. So the move has two parts: return to Original Medicare in a window that allows it, then apply for a Medigap policy.

The windows to leave Medicare Advantage are the Annual Enrollment Period, October 15 through December 7, with changes starting January 1; the Medicare Advantage Open Enrollment Period, January 1 through March 31, for people already in a Medicare Advantage plan; and Special Enrollment Periods that follow certain events, such as a plan not renewing or a move. Our guides to the Annual Enrollment Period and Special Enrollment Periods cover each one.

A Medigap policy cannot start until your Medicare Advantage coverage ends. Leaving Medicare Advantage is one decision and being accepted for a Medigap policy is another, which is why the rest of this guide is about when an insurance company must accept your application.

A guaranteed issue right is your right to get certain Medigap policies in limited situations outside your Medigap Open Enrollment Period. In those situations an insurance company must sell you a Medigap policy, must cover all your pre-existing conditions and cannot charge you more because of past or present health problems.

CMS also calls these rights Medigap protections. They are separate from your Medigap Open Enrollment Period, the one-time six-month window that starts the first month you have Part B and are 65 or older. During that window you can apply for any Medigap policy sold in your state without medical underwriting. It does not repeat, so for many people who leave Medicare Advantage later, a guaranteed issue right is what decides whether an insurer must accept them.

Under federal rules you have a guaranteed issue right when your Medicare Advantage plan is leaving Medicare, stops giving care in your area or you move out of its service area; during your first year after joining Medicare Advantage in certain cases (trial rights); and when a plan misled you or did not follow the rules.

Your plan is ending or you move. If your Medicare Advantage plan is leaving Medicare, stops giving care in your area or its network has a significant change, or you move out of its service area, you have the right to Medigap Plan A, B, D or G sold in your state, or Plan C or F if you were eligible for Medicare before January 1, 2020. Apply as early as 60 days before your Medicare Advantage coverage ends, or by the date in your plan's termination notice, and no later than 63 days after it ends. This right applies only if you go to Original Medicare rather than another Medicare Advantage plan. If your plan is ending for 2027, our guide to a Medicare Advantage plan ending in 2027 walks through the deadlines.

Trial right after joining at 65. If you joined a Medicare Advantage plan when you were first eligible for Medicare Part A at 65, and within the first year you decide to go to Original Medicare, you have the right to any Medigap policy sold in your state. Medicare.gov says your chance to drop the plan lasts for 12 months after you join a Medicare Advantage plan for the first time.

Trial right after leaving Medigap. If you dropped a Medigap policy to join a Medicare Advantage plan for the first time and have been in the plan less than a year, you have the right to your former Medigap policy if the same company still sells it. If it doesn't, you have the right to Plan A, B, D or G sold in your state, or Plan C or F if you were eligible for Medicare before January 1, 2020. For both trial rights, apply as early as 60 days before your coverage ends and no later than 63 days after, and CMS notes your rights may last an extra 12 months in some circumstances.

Your plan misled you or did not follow the rules. If you leave a Medicare Advantage plan because the company did not follow the rules or misled you, you have a guaranteed issue right to Plan A, B, D or G, or Plan C or F if you were eligible for Medicare before January 1, 2020. Apply no later than 63 days after your coverage ends.

Outside your Medigap Open Enrollment Period and the guaranteed issue situations, federal law does not require an insurance company to sell you a Medigap policy. It can use medical underwriting, which means reviewing your health history to decide whether to accept your application and what to charge.

CMS's guide says that outside your Medigap Open Enrollment Period you may pay more for a policy, fewer policies may be open to you, and an insurance company may turn you down if you don't meet its medical underwriting requirements. Even a policy bought during your Medigap Open Enrollment Period can, in some cases, wait up to six months before covering costs for a pre-existing condition. With a guaranteed issue right, the insurance company must cover your pre-existing conditions without that waiting period.

This is why timing matters. If you are thinking about leaving Medicare Advantage during the Annual Enrollment Period and none of the situations above applies to you, it helps to understand how Medigap underwriting would treat your application before you make the change.

The rights above are the federal minimum. CMS says you may have additional rights under your state's laws, and some states have additional open enrollment periods, including for people under 65. Your State Insurance Department or SHIP can tell you what applies where you live.

Medicare.gov's own Medigap tool notes that its answers cover only your federal rights. CMS also points out that Massachusetts, Minnesota and Wisconsin standardize their Medigap policies differently from other states, though people there have guaranteed issue rights too. Because state rules differ and change, this guide does not list them state by state; your state's insurance department is the authority on them.

Your State Health Insurance Assistance Program, or SHIP, can confirm whether you have a guaranteed issue right, and your State Insurance Department can help if you are denied a Medigap policy in one of these situations. Medicare.gov and 1-800-MEDICARE can answer questions about the federal rules.

Keep any letters, notices or claim denials that show your coverage ending, along with the envelopes they came in, because CMS says you may need copies with your Medigap application. A licensed independent agent can also explain how Medicare Advantage and Medigap differ and walk through the policies the agent offers in your area. For the bigger picture, see Medicare Advantage vs Medigap.