Switching From Medicare Advantage Back to Medigap

What Changes When You Leave Medicare Advantage

To use Medigap, you return to Original Medicare—Part A and Part B and buy a separate supplement policy. Medigap helps pay the deductibles, coinsurance and other costs included in that policy. It cannot pay your Medicare Advantage copayments or premiums.

For most Part B services, you usually pay 20% of the Medicare-approved amount after the Part B deductible. Some services have different cost sharing or none. Original Medicare has no yearly out-of-pocket limit for Part A and Part B. Your Medigap policy determines which of those costs it pays.

The key question is whether you can buy the Medigap policy you want before you leave Medicare Advantage. Outside a protected enrollment period or right, an insurer may review your health, charge more or decline your application. This is called medical underwriting. State law can give you additional protection.

A guaranteed issue right requires an insurer to sell you an eligible policy it offers without denying you or charging more because of your health. It also prevents exclusions for pre-existing conditions. An application may still contain health questions; the protection concerns how the insurer can use the answers. Supply accurate answers and proof of your right.

If your application is denied, ask for the reason in writing. If you believe the insurer failed to honor a protected right, contact your State Insurance Department. SHIP can help you identify your rights and prepare your application.

If Your Medicare Advantage Plan Ends

You may have a guaranteed issue right if your plan leaves Medicare, stops serving your area, or you move outside its service area. For these situations, you must switch to Original Medicare to use Medigap. Joining another Medicare Advantage plan does not let you use Medigap alongside it.

Keep the plan’s notice and its envelope. Confirm what the notice means: a plan ending, a service-area change and an automatic move to another plan are not interchangeable. Our 2027 plan-change guide explains what to ask your plan and Medicare.

When to Apply—and When Coverage Starts

For a qualifying involuntary termination, the federal application period starts when you receive the termination notice and ends 63 days after your Medicare Advantage coverage ends. The final deadline runs from coverage ending, not from the day the notice arrived.

For example, if you receive a notice in October saying your coverage ends December 31, contact Medigap insurers and SHIP then. Do not assume you must wait until November to apply. Ask the insurer to recognize your guaranteed issue right and confirm your requested effective date. If it refuses to accept your application, ask for a written explanation and contact your State Insurance Department promptly.

Qualifying voluntary disenrollment uses a different start date: generally 60 days before disenrollment takes effect, through 63 days afterward. Moving outside your plan’s service area can fall under this rule. A voluntary departure does not, by itself, create a guaranteed issue right; first confirm that your situation qualifies.

Medicare’s consumer guidance describes the 60-day advance application period, while its current Medigap handbook also distinguishes leaving voluntarily from a plan termination. Your notice and reason for leaving matter. SHIP can help you check which application period applies.

Do not wait until the final application deadline to arrange coverage. Ask for Medigap to start when you return to Original Medicare, with no gap after your Medicare Advantage coverage. Medigap cannot start while your Medicare Advantage coverage is still in effect. If the supplement starts later, you may owe Original Medicare cost sharing during the gap.

The Medigap application window is separate from your opportunity to leave Medicare Advantage or join Part D. Fall Medicare Open Enrollment runs October 15–December 7 for changes effective January 1. If you are already in Medicare Advantage, you can also return to Original Medicare once during the Medicare Advantage Open Enrollment Period, January 1–March 31, and join a separate Part D plan. That change generally starts the first day of the following month. This period does not itself guarantee that you can buy Medigap. A qualifying plan nonrenewal or other circumstance may give you a Special Enrollment Period. Confirm the election deadline and start date with Medicare; a remaining Medigap application right does not itself let you change Medicare plans at any time.

Which Medigap Policies the Right Covers

For a qualifying loss of Medicare Advantage coverage, the standard guaranteed-issue choices generally depend on when you first became eligible for Medicare:

An insurer must sell you a qualifying policy it offers and has available to new enrollees. Check which insurers sell the letter you want in your state. These are the standard choices reflected in the NAIC model rules; state law may provide more choices or protections. Massachusetts, Minnesota and Wisconsin standardize Medigap differently. If you have Medicare before age 65 because of disability or ESRD, check policy availability and your federal and state rights with SHIP before relying on these choices.

Plans C and F cover the Part B deductible and cannot be sold to people newly eligible for Medicare on or after January 1, 2020. Plans D and G replace them for those beneficiaries under the standard guaranteed-issue rules. Being eligible before 2020 does not require that you already owned C or F.

Do not assume this particular right guarantees Plans M or N. An insurer may use underwriting for a policy outside your protected choices. Trial rights and state rules can be broader. Ask the insurer and SHIP about the exact policy you want before making your Medicare Advantage election.

If You Want to Leave a Plan That Is Continuing

Medicare Open Enrollment lets you change Medicare coverage, but it is not an annual Medigap open enrollment period. Your Medigap Open Enrollment Period generally lasts six months, starting the first month you are 65 or older and enrolled in Part B.

Two federal trial rights may also help:

• You joined Medicare Advantage when first eligible for Part A at age 65 and leave within 12 months. This trial right generally allows any Medigap policy sold in your state, subject to the restriction on Plans C and F for people newly eligible from 2020 onward.
• You dropped Medigap to try Medicare Advantage for the first time and leave within 12 months. You can generally return to your former policy if the same insurer still offers it. If it is unavailable, the standard guaranteed-issue choices apply instead. Older policies with prescription drug benefits have additional rules.

Certain interrupted trial periods can last longer. Have SHIP or your State Insurance Department confirm your eligibility, dates and policy choices.

Joining Medicare Advantage for the first time at 70 after years in Original Medicare without Medigap does not, by itself, satisfy either trial right. You may still have another federal protection or rights under state law. Check before leaving your plan, while you can still compare your coverage options.

Arrange Drug Coverage at the Same Time

A new Medigap policy does not include Part D prescription drug coverage. If you are leaving a Medicare Advantage plan with drug coverage, ask when that coverage will stop and when your replacement will start.

A separate Part D plan may be needed unless you have other creditable drug coverage—coverage expected to pay, on average, at least as much as standard Medicare drug coverage. VA, TRICARE and some employer or retiree coverage can qualify; confirm your own coverage rather than assuming.

Going 63 consecutive days or more without Part D or other creditable drug coverage after your initial enrollment period can trigger a Part D late-enrollment penalty. A shorter gap is not free coverage. You can still owe prescription costs while uninsured. Keep any creditable-coverage notice and coordinate the new plan’s effective date.

What to Do Next

1. Keep your notice and proof of coverage. Save the letter, envelope, emails and any relevant claim denials. These may help establish your guaranteed issue right.
2. Confirm your rights and dates. Ask SHIP and the insurer when you can apply, which policies are protected, and when coverage can start. Separately confirm your Medicare Advantage and Part D election deadlines with Medicare.
3. Compare the exact Medigap policy. Check the plan letter, premium and pricing method. Ask whether the quote is for a standard or high-deductible policy, and whether it is Medicare SELECT, which can require particular providers for full benefits.
4. Apply with proof of your right. Ask for written confirmation of acceptance and the effective date. Do not assume a submitted application means the policy has been issued.
5. Coordinate the switch. Confirm Original Medicare, Medigap and any Part D start dates so you understand any gap and its costs. Contact your benefits administrator before changing employer or retiree coverage.

Get free, personalized help from SHIP or call 1-800-MEDICARE. For a dispute about a Medigap insurer’s application decision, contact your State Insurance Department.

Sources

• Medicare: Choosing a Medigap Policy — guaranteed issue, application timing, trial rights and completing an application; see pages 15–19 and 24.
• Social Security Act §1882 — subsection (s)(3) sets guaranteed-issue protections, trial rights and the separate involuntary and voluntary application periods; subsection (z) restricts policies covering the Part B deductible for newly eligible beneficiaries.
• NAIC Medicare Supplement model regulation — section 12E identifies standard guaranteed-issue policies, including K and L; section 9.2C substitutes D/G for C/F for beneficiaries newly eligible from 2020. State implementation and additional protections must be checked locally.
• Medicare: When can I buy a Medigap policy? — eligibility depends on your circumstances and state rights.
• Medicare: Joining a plan and Special Enrollment Periods — Medicare Advantage and Part D election periods.
• Medicare costs, Medigap costs and how Medigap works — cost sharing, premiums and coverage limits.
• Medicare: Avoid late-enrollment penalties — Part D creditable coverage and the 63-day gap rule.

Frequently Asked Questions