How to Switch From Medicare Advantage to Medigap

The Basic Mechanics

To switch from Medicare Advantage to Original Medicare, you disenroll from your Medicare Advantage plan. This can be done during the Medicare Advantage Open Enrollment Period (January 1 through March 31) or during the Annual Election Period (October 15 through December 7). When you leave a Medicare Advantage plan, you return to Original Medicare.

Returning to Original Medicare means you will need to manage the cost-sharing gaps that Original Medicare does not cover. For most people, this means considering a Medigap supplement and a standalone Part D prescription drug plan.

The Underwriting Challenge

Here is where the switch becomes complicated. If your six-month Medigap Open Enrollment Period has already passed (which it likely has, since it occurs when you first turn 65 and enroll in Part B), you are subject to medical underwriting in most states when applying for a Medigap policy.

Medical underwriting means the insurance company can review your health history. If you have developed health conditions since you originally enrolled in Medicare, the insurer may charge a higher premium, exclude coverage for pre-existing conditions, or deny the application entirely.

This is one of the most significant asymmetries in Medicare: switching from Original Medicare to Medicare Advantage is generally straightforward during Open Enrollment, but switching back often comes with underwriting barriers.

Guaranteed Issue Rights

Federal law provides "guaranteed issue rights" in certain specific circumstances where you can buy a Medigap policy without medical underwriting, even outside your Open Enrollment Period. These situations include:

• Your Medicare Advantage plan leaves your area or stops providing coverage
• You move out of your plan's service area
• You joined a Medicare Advantage plan when you first became eligible for Medicare Part A at 65, and you want to switch to a Medigap policy within the first 12 months

Some states provide additional protections beyond the federal minimums. A few states (such as Connecticut, Massachusetts, Maine, and New York) offer annual Medigap open enrollment or continuous guaranteed issue rights. Check your state's specific rules.

The "Trial Right"

If you are new to Medicare and join a Medicare Advantage plan for the first time, you have a "trial right" — a 12-month window during which you can return to Original Medicare and purchase a Medigap policy with guaranteed issue. This trial right exists so that new Medicare beneficiaries can try Medicare Advantage without permanently losing access to Medigap.

After this 12-month trial period, the guaranteed issue protection generally does not apply in most states (unless one of the other guaranteed issue situations occurs).

Planning the Switch

If you are considering switching from Medicare Advantage to Original Medicare with a Medigap supplement:

• Check whether you have any guaranteed issue rights that would allow you to buy Medigap without underwriting
• Check your state's specific Medigap rules — some states offer protections beyond the federal minimum
• Apply for the Medigap policy before disenrolling from Medicare Advantage, so you know whether you can get coverage before you make the switch
• Contact your State Health Insurance Assistance Program (SHIP) for free, personalized guidance

"The door from Medicare Advantage to Medigap opens easily in your first year. After that, it may require medical underwriting to walk through — and for some, it may not open at all."