Medicare Advantage vs. Medigap: The Underwriting Trap

Here's the short answer. You can leave a Medicare Advantage plan and go back to Original Medicare at set times each year. But a Medigap company may not have to sell you a policy. After your first year in Medicare Advantage, most people have no federal guarantee. The company can look at your health history, charge you more, or say no. The one big exception is the 12-month trial right. It can protect you if you act within 63 days after your plan coverage ends.

Why Medigap and Medicare Advantage are a one-or-the-other choice

Medigap (Medicare Supplement insurance) pays some costs that Original Medicare leaves to you. It works only with Original Medicare. It does not work with Medicare Advantage. It is illegal for anyone to sell you a Medigap policy while you are in a Medicare Advantage plan, unless the policy starts only after that plan coverage ends.

So the choice is not a side-by-side test. You pick one path. If you later want to switch paths, the rules about Medigap decide how easy it is. This page is about those rules. For a neutral look at how the two paths differ, see Choosing Coverage. This site does not recommend plans.

What "underwriting" means

Underwriting is when an insurer reviews your health before it decides to sell you a policy. For Medigap, the company may ask about your health. It can then turn you down or charge more.

You are protected from this in two cases:

• Your Medigap Open Enrollment Period. This is a one-time, 6-month window. It starts when you are 65 or older and have Part B.
• A guaranteed issue right. This is a situation in which the company must sell you a policy.

Outside those two cases, there is no federal guarantee. If you can buy a policy, it may cost more because of health problems. Some states add rules of their own, so check with your State Insurance Department.

The trap: why year one matters

Say you join Medicare Advantage when you first get Medicare. Your 6-month Medigap window starts when you have Part B. It passes while you are in the plan, because you cannot use it there. In year two or later, you may want Original Medicare. Now you are asking a company to sell you Medigap with no federal guarantee. If your health changed, the company can say no or charge more.

That is the trap. Leaving Medicare Advantage is easy. Getting Medigap afterward may not be.

The 12-month trial right

Medicare gives you a "trial" if you try Medicare Advantage and want to go back. Two cases qualify.

• You joined Medicare Advantage when you were first eligible for Medicare, and it has been less than a year. You can switch to Original Medicare. You can then buy any Medigap policy sold in your state.
• You dropped a Medigap policy to try Medicare Advantage for the first time, and it has been less than a year. You can get your old policy back if the same company still sells it. If not, you can buy certain standard plans from any company in your state.

The right applies only if you switch to Original Medicare. It does not apply if you join another Medicare Advantage plan.

The 63-day clock

Guaranteed issue rights run on a strict clock. You must apply for the Medigap policy:

• As early as 60 days before your Medicare Advantage coverage ends.
• No later than 63 days after it ends.

Medigap coverage cannot start until your Medicare Advantage coverage ends. Keep every letter, notice, and email from your plan. You may need them to prove your coverage ended.

When you can leave Medicare Advantage

You can leave your plan at certain times:

• The fall Open Enrollment Period, October 15 – December 7. Coverage starts January 1.
• The Medicare Advantage Open Enrollment Period, January 1 – March 31. You can drop the plan and return to Original Medicare.
• A Special Enrollment Period, such as when you move out of the plan's service area.

Our step-by-step guide covers each one: Switching from Medicare Advantage to Original Medicare. If you only want a different Medicare Advantage plan, see Switching Medicare Advantage Plans and the Medicare Advantage Open Enrollment Period. For plan letters and what Medigap covers, see Medigap Plans.

Questions to ask before you leave your plan

• Am I inside my first 12 months in Medicare Advantage?
• Do I have another guaranteed issue right, such as a plan that is leaving my area?
• Does my state add protections beyond federal law?
• Can I confirm a Medigap company will sell to me before my plan coverage ends?

Your State Health Insurance Assistance Program (SHIP) gives free, one-on-one help. Find yours in the SHIP directory.

Common Questions