From Medicare.org
It's usually not about an insurer walking away from their patrons, typically. More common is when people can lose coverage "through no fault of their own" by simply moving out of the area covered by their current carrier. At that point, they fall into the "guaranteed issue" category. Those are basic facts that most people here probably would agree upon, I think. I searched for "default medigap plan guaranteed issue" and got That's from "omahainsurancesolultions", so take it with whatever quantity of salt you wish. I didn't take the time to actually find the law. I'm probably not nearly smart enough to interpret the actual law if it were laid out in front of me, hehe!
Understanding Guaranteed Issue Rights
Private insurance companies are lawfully obligated to sell you a Medicare Supplement policy if you enroll during your initial enrollment period you qualify for guaranteed issue rights
Guaranteed issue rights are also known as Medigap protections. If you qualify, a private insurance company must abide by government regulations to give you access to certain Medicare Supplement plans, it must offer coverage for all pre-existing health conditions, and it cannot charge you a higher premium for the insurance plan due to health problems, either in the past or present.
Here is a list of some situations that may provide you with guaranteed issue rights to purchase a Medigap plan if you meet specific criteria:
• You have another form of health coverage that is changing or that you are going to lose within a short period of time.
• You have a Medicare Advantage (Part C) plan that is leaving Medicare or is ending its coverage in your area. This is also true if you are moving out of your plan’s service area.
• You are covered by Original Medicare Parts A and B as well as a group health plan provided by your employer or union that is ending. This is true if the group plan has been offering extended coverage after Original Medicare coverage ends.
• You are covered by Original Medicare Parts A and B and Medicare SELECT but you are leaving your coverage area for Medicare SELECT.
• You have a Medicare Advantage (Part C) plan but are switching back to Original Medicare.
• You initially had a supplement plan but now have a Medicare Advantage plan (and have had it for less than one year), and you wish to change back to a Medicare Supplement plan.
• Your private insurance provider goes bankrupt or your policy ends in a way that is not your fault.
• Your private insurance provider has been misleading or fraudulent and you decide to cancel your plan because of this.
In some cases, if you are in your “trial right” period for a Medicare Advantage (Part C) plan, which is up to 12 months after initial enrollment, you also have guaranteed issue rights to purchase a private supplemental health insurance plan during this special enrollment period. Federal law allows 63 days of guaranteed issue rights after you disenroll from your Medicare Advantage plan, giving you time to enroll in a Medicare supplement plan.