Switching From Medicare Advantage to Medigap

Medicare is built so you can change your Medicare Advantage plan every autumn, for any reason, for the rest of your life, and your health never comes into it. Buying a Medigap policy works under a different set of rules, and after one specific window closes, insurers in most states are allowed to ask about your health and say no.

Nobody hides this. It is simply not the part of the conversation that comes up when you are 65, healthy, and looking at a plan with a low premium and dental coverage attached. It becomes the whole conversation about a decade later.

The window most people spend without noticing

Your Medigap open enrollment period runs six months, starting the first month you are both 65 or older and enrolled in Part B. It happens once. There is no repeat, no annual version, and no way to reopen it.

During those six months you can buy any Medigap policy sold in your state at that insurer's standard rate, regardless of your health history. No questions, no exam, no exclusions for conditions you already have.

After it closes, that protection ends. In most states an insurer reviewing a later Medigap application may look at your health history and decide to charge you a higher rate, exclude a pre-existing condition for a period, or decline the application entirely. That is medical underwriting, and it is legal and routine.

When you do have a guaranteed right

Federal law provides guaranteed issue rights in a limited set of situations. Where one applies, an insurer must sell you certain Medigap policies, cannot use your health against you, and cannot exclude a pre-existing condition. The common ones are worth knowing by name.

• The trial right at 65If you joined a Medicare Advantage plan when you first became eligible at 65 and you leave within the first twelve months, you have a guaranteed right to buy a Medigap policy.
• The trial right after dropping MedigapIf you had a Medigap policy, dropped it to try Medicare Advantage for the first time, and change your mind within twelve months, you can generally return to a Medigap policy.
• Your plan leaves or you moveIf your Medicare Advantage plan stops serving your area, ends its contract, or you move outside its service area, a guaranteed issue right generally applies.
• The plan broke its rulesIf a plan misled you or failed to follow its own terms, that can trigger a guaranteed issue right as well.

These rights are time-limited, usually to about sixty days around the triggering event, and they need to be claimed rather than granted automatically. Missing the deadline puts you back into underwriting.

What underwriting actually asks

A Medigap application outside a protected window is not a formality. The insurer asks about hospital stays and surgery in recent years, ongoing treatment, and a list of specific conditions. Some are what people expect, such as active cancer treatment or dialysis. Others surprise them: a recent joint replacement recommendation, a condition that is well managed but chronic, or a medication that signals something the insurer prices for.

Different insurers weigh the same history differently, so being declined by one does not mean being declined by all. That is genuinely where a broker earns their keep, because knowing which carriers view a specific condition more favourably is not information you can look up. But no broker can turn a decline into an approval, which is why the timing matters far more than the shopping.

What this does not mean

It does not mean Medicare Advantage is the wrong choice. For a great many people it is the right one: the costs are lower up front, the network covers the doctors they use, and the extra benefits are real. Millions of people are well served by it, and switching to Medigap later is something most of them never want to do.

What it means is that the decision at 65 is not symmetric with the decision at 75, and it should be made knowing that. If the network works for you and the budget matters more than nationwide access, Advantage is a sound choice. If you travel constantly, split the year between states, or expect complex care where you do not want prior authorisation standing between you and a specialist, the six-month window is the moment to act on that, not later.

Compare how Medicare Advantage and Medigap work