Losing a Medicare Advantage plan does not have to mean losing the chance to buy a Medigap policy without a health screening. Federal rules give members whose Medicare Advantage plan leaves Medicare or leaves their service area a guaranteed-issue right, one that requires an insurer to sell a Medigap policy regardless of health history, and the window to use it runs up to 63 days after the old coverage ends. Outside a right like this one, an insurer can generally ask about health history before agreeing to sell a Medigap policy at all.
The Guaranteed-Issue Right, Defined
Medicare.gov’s own page on changing a Medigap policy puts the general rule plainly: outside the initial enrollment period, “you generally lack federal rights to switch unless” a person has a “guaranteed issue right,” defined there as a situation in which “an insurance company can’t deny you a Medigap policy.” A Medicare Advantage plan leaving Medicare or leaving a member’s area is one of the specific situations that triggers that right, according to CMS’s own Medigap consumer guide.
Without that protection, an insurer reviewing a Medigap application from someone who is simply switching plans on their own initiative can ask about health history and, depending on the state, price or decline the policy accordingly. The guaranteed-issue right removes that screening entirely for the specific window tied to the Medicare Advantage plan’s exit.
The practical effect is largest for someone managing an ongoing health condition. Medical underwriting outside a guaranteed-issue right is exactly the process that can make a Medigap policy expensive or unavailable for someone with a history of claims, which is why the specific trigger of a Medicare Advantage plan leaving carries its own dedicated right rather than leaving that member to shop under the same rules as anyone switching by choice.
Two references for a plan-leaving decision: The 2027 Medicare Open Enrollment Decision Kit walks through Original Medicare vs. Medicare Advantage and includes the Open Enrollment calendar, both relevant before deciding whether the 63-day Medigap window is even the right path compared with simply choosing a different Medicare Advantage plan. Open The 2027 Medicare Open Enrollment Decision Kit.
Which Medigap Plans Are Covered
The guaranteed-issue right does not apply to every Medigap plan on the market. CMS’s guide specifies that a member in this situation can buy “Medigap Plan A, B, C*, D*, F*, or G* that’s sold by an insurance company in your state,” a defined list rather than an open choice among every letter Medigap offers. The asterisks matter, and they show up again in a separate restriction on Plans C and F that applies regardless of the guaranteed-issue right.
Plans A and B are the simplest of the group and carry no asterisk in CMS’s guide, while D, F and G add more extensive coverage of Medicare’s own cost-sharing. A member using the guaranteed-issue right still has to compare those letters against each other, since a guarantee of acceptance is not a guarantee that every listed plan carries the same premium or the same coverage from one insurer to the next.
The 60-Before, 63-After Window
The guaranteed-issue window is not limited to the period after coverage ends. CMS’s guide states the right runs “60 days before the date your Medicare Advantage Plan coverage ends,” for someone who already knows they are leaving, through “no more than 63 days after your Medicare Advantage Plan coverage ends.” That structure gives a member two months of runway to shop before the change even happens, plus roughly nine more weeks afterward, rather than a single hard cutoff on one side only.
The advance half of the window exists because a Medicare Advantage plan leaving Medicare or an area is not usually a surprise sprung with no notice. Insurers are required to tell affected members ahead of the change, which is what makes the 60-day advance portion of the guaranteed-issue right usable in practice rather than theoretical.
Why the New Policy Can’t Start Early
Timing the purchase does not mean the new coverage starts early. The same CMS guide is explicit that “Medigap policies can’t start until your Medicare Advantage Plan coverage ends,” so a member who buys during the 60-day advance window is locking in the guaranteed-issue price and acceptance, not accelerating the actual start date of the Medigap benefits.
Outside the Guaranteed-Issue Window
Once the 63rd day after the Medicare Advantage plan’s exit passes, the guaranteed-issue protection tied to that specific event ends. Medicare.gov’s page on buying a Medigap policy notes that insurers generally are not obligated to sell a policy at that point unless a different guaranteed-issue situation applies, and can ask about health history before agreeing to sell one, or a person can wait for another qualifying event, such as another future guaranteed-issue right, if one arises.
Choosing a New Medicare Advantage Plan Instead
The guaranteed-issue right described here is specific to Medigap. A member whose Medicare Advantage plan is leaving can instead enroll in a different Medicare Advantage plan for the coming year without going through medical underwriting at all, since Medicare Advantage plans generally must accept any eligible applicant who enrolls during a valid enrollment period. That path sidesteps the Medigap guaranteed-issue question entirely, which is why the choice between a new Medicare Advantage plan and a move to Original Medicare with Medigap comes before the 63-day clock becomes the deciding factor.
The Choice Behind the 63-Day Window
A guaranteed-issue right solves one problem, buying a Medigap policy without a health screening, but it does not answer the separate question of whether Original Medicare plus a Medigap policy beats simply choosing a different Medicare Advantage plan, a decision that has to be made before the window closes.
The 2027 Medicare Open Enrollment Decision Kit lays out the Original Medicare vs. Medicare Advantage comparison alongside pricing extra benefits, the two pieces most relevant to a household weighing a Medigap purchase against another Medicare Advantage plan.
Weigh both paths against the 63-day window with The 2027 Medicare Open Enrollment Decision Kit.
This article was produced with AI assistance and reviewed by a human editor, based on CMS’s own Medigap guidance.
