Switching from Medicare Advantage to Medigap: What to Know First

Switching from a Medicare Advantage plan back to Original Medicare with a Medigap policy is possible at almost any time, but getting approved for the Medigap policy is not guaranteed outside specific windows. Most Medigap insurers can ask health questions and decline coverage or charge more based on your answers, unless you have a guaranteed-issue right. Whether you have that right depends on your situation and, in many cases, on the state you live in.

Why people consider this switch

People generally start looking at this switch for a handful of recurring reasons. Some want the wider provider access that Original Medicare plus a Medigap policy offers, since it isn't limited to a plan's network the way Medicare Advantage is. Some have had a difficult experience with prior authorization or a denied claim and want the more predictable cost-sharing structure a Medigap policy provides. Others are drawn by the idea of not needing plan approval before seeing a specialist. These are legitimate reasons to look into the switch, but none of them change the underwriting reality described below.

The underwriting reality

This is the part that gets skipped in a lot of casual conversation about switching, and it is the single most important thing to understand before you act on it.

When you first became eligible for Medicare, you had a one-time Medigap open enrollment period — six months starting when you were both 65 and enrolled in Part B — during which insurers in most states had to sell you any Medigap policy they offered, at their standard rate, regardless of your health. If you used that window to enroll in Medicare Advantage instead of a Medigap policy, or if that window has simply passed, applying for a Medigap policy now generally means going through medical underwriting.

Medical underwriting means the insurer can ask about your health history and current conditions, and in most states, it can do one of three things with that information: charge you a higher premium, deny you coverage for a specific pre-existing condition for a period of time, or decline to issue you a policy at all. This is different from Medicare Advantage, which generally cannot deny you based on health during an enrollment period you qualify for. It's also different from Part D, which has its own separate rules. Medigap underwriting is its own process, governed differently than either of those.

There is one major exception: guaranteed-issue rights.

Why your state matters

Federal law sets a baseline for Medigap guaranteed-issue rights, but states are allowed to expand on that baseline, and many have. Some states require Medigap insurers to offer at least one policy on a guaranteed-issue basis on a regular schedule — for instance, around your birthday or your Medicare enrollment anniversary — regardless of the federal triggering events. Other states have no such rule, and the federal baseline is what applies.

This means two people in similar health, in similar circumstances, living in different states, can have very different experiences applying for the same type of Medigap policy. One might be guaranteed acceptance on a specific date each year. The other might need to pass underwriting or apply during one of the federal guaranteed-issue windows. There is no substitute for checking your own state's specific rules rather than assuming what applies elsewhere applies to you. Your state insurance department's website is generally the most reliable place to look, alongside Medicare.gov's state-by-state Medigap information.

What this means practically

If you're considering this switch, a few things follow directly from the underwriting rules above:

Check whether you have a guaranteed-issue right before assuming underwriting is required. Certain events — including some plan terminations and moves — can trigger a right to buy a Medigap policy without health questions, generally on a limited timeline. If one of these applies to you, it is worth confirming before you assume you'll need to go through full underwriting.

If underwriting does apply, understand what it can mean for cost and approval. In states without additional protections, an insurer can decline you outright for certain health conditions, or approve you at a higher premium. This is worth knowing before you drop your current Medicare Advantage coverage, not after.

Timing matters relative to your current plan. If you're planning to leave a Medicare Advantage plan, think through the sequence: applying for the Medigap policy first, before ending your current coverage, generally reduces the risk of a coverage gap if the Medigap application doesn't go through the way you expect.

What underwriting actually involves

If you don't have a guaranteed-issue right and need to go through medical underwriting, it helps to know roughly what that process looks like so it isn't a surprise. Most Medigap applications include a health questionnaire covering current conditions, recent hospitalizations, and certain medications. The insurer reviews your answers against its own underwriting guidelines, which differ from company to company — a condition that leads one insurer to decline coverage might lead another to approve at a standard rate, or approve with a temporary waiting period for that specific condition.

This is one of the reasons it can be worth looking at more than one insurer if you're applying through underwriting rather than a guaranteed-issue right. Insurers are not required to use identical underwriting standards, and a policy that offers the same standardized benefits under Medigap's letter-plan system can still come with different underwriting outcomes depending on which company you apply to. Comparing insurers, not just plan letters, is part of a thorough approach when underwriting is involved.

It's also worth being honest on the application itself. Medigap applications typically ask you to attest to the accuracy of your answers, and inaccurate answers discovered later can affect your coverage. This isn't a reason to avoid applying — it's a reason to take the health questionnaire seriously rather than treating it as a formality.

What Medigap does and doesn't change

Switching to a Medigap policy changes how your cost-sharing works and removes the network restrictions of Medicare Advantage, but it does not automatically include drug coverage. Most Medigap policies don't cover prescription drugs, so you would generally also need a stand-alone Part D plan alongside your Medigap policy. That's a second decision layered on top of the Medigap underwriting question, and it's worth planning for both at once rather than treating them separately.

The bottom line

Switching from Medicare Advantage to a Medigap policy is not blocked by any Medicare rule outright, but it is not automatic either. Outside your initial Medigap enrollment window or a qualifying guaranteed-issue event, insurers can generally ask health questions and can decline or rate based on the answers. Which guaranteed-issue rights apply to you depends on your circumstances and, often, on the specific rules of the state you live in. Before ending Medicare Advantage coverage you currently have, it is worth confirming exactly where you stand on underwriting, not assuming.

For the federal rules on Medigap enrollment and guaranteed-issue rights, see Medicare.gov's Medigap basics and CMS's Medigap guidance.