Switching from Medicare Advantage to Original Medicare: When and How to Do It

Your parent signed up for Medicare Advantage, and now the network is too narrow, the prior authorization requirements are blocking care, or the out-of-pocket costs are higher than expected. They want to switch back to Original Medicare — but the timing, paperwork, and Medigap implications make it more complicated than the initial enrollment.

When Your Parent Can Switch

There are two main windows for leaving Medicare Advantage and returning to Original Medicare:

Medicare Advantage Open Enrollment Period (MA-OEP): January 1 through March 31. During this window, anyone currently enrolled in a Medicare Advantage plan can disenroll and return to Original Medicare. Coverage under Original Medicare begins the first of the month after the plan receives the disenrollment request. Your parent will also need to enroll in a standalone Part D plan for prescription drug coverage, since Original Medicare doesn't include drug coverage.

Annual Election Period (AEP): October 15 through December 7. Your parent can drop their Medicare Advantage plan and switch to Original Medicare with a standalone Part D plan. Coverage starts January 1.

Special Enrollment Periods may also apply if your parent moves out of the plan's service area, the plan leaves the area, or the plan loses its Medicare contract.

The Medigap Problem

Here's where it gets complicated. When your parent returns to Original Medicare, they'll likely want a Medigap (Medicare Supplement) policy to cover the 20% coinsurance, deductibles, and other gaps that Original Medicare doesn't pay.

But Medigap policies require medical underwriting in most states — meaning the insurer can deny coverage or charge higher premiums based on your parent's health conditions. The exception is guaranteed issue rights.

Guaranteed issue situations when switching from Medicare Advantage:

• Trial right (first 12 months): If your parent joined Medicare Advantage when they first became eligible for Medicare at 65, they have 12 months to switch back and buy any Medigap policy sold in their state without medical underwriting.
• Trial right (dropped Medigap): If your parent dropped a Medigap policy to join Medicare Advantage for the first time and switches back within 12 months, they can buy their old Medigap plan back from the same insurer (or Plans A, B, C, D, F, or G if the old plan isn't available).

Outside these trial rights, Medigap guaranteed issue depends entirely on state law. Some states (like New York, Connecticut, and Massachusetts) require continuous open enrollment or annual open enrollment for Medigap. Most do not.

If your parent has been on Medicare Advantage for several years and has developed health conditions, getting a Medigap policy could be difficult or impossible in states without guaranteed issue protections. This is the single biggest factor to evaluate before switching.

Step-by-Step: How to Switch

1. Check Medigap availability first. Before disenrolling from Medicare Advantage, contact Medigap insurers in your parent's state to confirm they can get a policy. If they don't have guaranteed issue rights, request quotes and check whether pre-existing conditions will affect pricing or availability.

2. Disenroll from Medicare Advantage. Call the plan directly or call 1-800-MEDICARE. During the MA-OEP (January through March) or AEP (October through December), you can disenroll by phone.

3. Enroll in a standalone Part D plan. Original Medicare doesn't include prescription drug coverage. Your parent needs a separate Part D plan to avoid the Part D late enrollment penalty. Use Medicare.gov's plan finder to compare options based on your parent's medication list.

4. Apply for Medigap. Submit the application during the guaranteed issue window if applicable. Coverage effective dates should align with the Medicare Advantage termination date to avoid gaps.

5. Confirm the transition. Verify with 1-800-MEDICARE that your parent's coverage shows as Original Medicare (Parts A and B) with the new Part D plan. Check that the Medicare Advantage plan shows as terminated.

When Switching Isn't Worth It

Medicare Advantage plans have downsides (network restrictions, prior authorizations), but they also include annual out-of-pocket maximums that Original Medicare doesn't. In 2026, the average Medicare Advantage out-of-pocket maximum is around $7,550. Original Medicare has no cap — without a Medigap policy, costs can be unlimited.

If your parent can't get a Medigap policy, switching to Original Medicare exposes them to uncapped costs. In that scenario, staying with Medicare Advantage (or switching to a different Advantage plan) may be the safer choice.

Make the Switch With Confidence

The Caregiver's Guide to Managing a Parent's Medicare includes a plan comparison worksheet, Medigap guaranteed issue checklist, and the annual calendar of enrollment windows — so you can time the transition correctly and avoid coverage gaps.

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