Surprisingly, yes, but . . .  (1) Yes, you can legally join a Medicare Advantage plan when you have a Medicare Supplement, at least technically.

(2)  But no, you cannot use both a Medicare Supplement and a Medicare Advantage plan together (the two types of Medicare coverage do not work together to bring you more benefits).

As noted by the Centers for Medicare and Medicaid Services (CMS):

"Medigap policies can’t work with Medicare Advantage Plans.  If you decide to keep your Medigap policy, you’ll have to pay your Medigap policy premium, but the Medigap policy can’t pay any deductibles, copayments, coinsurance, or premiums under a Medicare Advantage Plan.

So, if you join a Medicare Advantage Plan, you may want to drop your Medigap policy.

Contact your Medigap insurance company to find out how to disenroll.  However, if you leave the Medicare Advantage Plan you might not be able to get the same Medigap policy back, or in some cases, any Medigap policy unless you have a “trial right.”  [Remember y]our rights to buy a Medigap policy may vary by state. You always have a legal right to keep the Medigap policy after you join a Medicare Advantage Plan.  However, because you have a Medicare Advantage Plan, the Medigap policy would no longer provide benefits that supplement Medicare."

Question:  Was my Medicare Supplement automatically cancelled when I joined a Medicare Advantage plan?

No.  If you were enrolled in a Medicare Supplement or Medigap plan and then joined a Medicare Advantage plan, please be sure that your Medicare Supplement knows of your plan change - and disenroll from the Medicare Supplement - if you so choose (read more below).

If your Medicare Supplement was not aware that you changed to a Medicare Advantage plan, it is possible that you will still be charged monthly premiums for your old Medicare Supplement – although you cannot use the Medigap plan once you join a Medicare Advantage plan.

Question:  So why would anyone want to stay enrolled in a Medicare Supplement (and keep paying for coverage they can't use) after joining a Medicare Advantage plan?

Some Medicare beneficiaries decide to keep paying their Medicare Supplement premium even though they have joined a Medicare Advantage plan so that they have the option of returning to the Medicare Supplement without medical underwriting should they decide to leave the Medicare Advantage plan after the expiration of the CMS Trial Right (returning to Medicare Supplement within 12 months of joining the Medicare Advantage plan).

In an essence, some people like to have a longer Medicare Advantage plan "test drive" while reserving the right to return to their Medicare Supplement - especially when these people have access to a $0 premium Medicare Advantage plan that includes drug coverage (MAPD) in their Service Area (ZIP or county).

See also:  Do I have a trial right to leave my new Medicare Advantage plan within the first 12 months and return to my previous Medicare Supplement?

Key Point:  You cannot use your Medicare Supplement once you join a Medicare Advantage plan.

But if you keep your Medicare Supplement along with your Medicare Advantage plan, you could go back to your Medigap plan along with Original Medicare Part A and Part B, without underwriting, at any point when you are able to drop your Medicare Advantage plan -- such as if you drop your Medicare Advantage plan during the AEP or during the MA-OEP.

(further reference: Choosing a Medigap Policy: A Guide to Health Insurance for People with Medicare, CMS)

See the related Frequently Asked Question:  "Can I join a Medicare Supplement if I already have a Medicare Advantage plan?"

You can also click here to learn more about Medicare Advantage plans.

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