Updated August 3, 2026. Quick answer: going back to Original Medicare is the easy half. Buying the Medigap policy that makes it affordable is the half that depends on your health — unless you fall into a guaranteed-issue right, and those are specific, listed, and deadline-bound.
What a guaranteed-issue right gives you
“If you have a guaranteed issue right, an insurance company: Must sell you a Medigap policy. Must cover all your pre-existing health conditions. Can’t charge you more for a Medigap policy because of past or present health problems.”
The federal situations
| Situation | What you may buy | Deadline |
|---|---|---|
| Your Medicare Advantage plan leaves Medicare, stops serving your area, you move out of its service area, or its network changes significantly – and you return to Original Medicare | Plan A, B, C*, D*, F* or G* from an insurer in your state | 60 days before coverage ends, or no more than 63 days after |
| You have Original Medicare plus employer, union, retiree or COBRA coverage that pays after Medicare, and that coverage is ending | Plan A, B, C*, D*, F* or G* | no more than 63 days after the latest of the coverage-end date, the notice date, or a claim-denial date |
| You have Original Medicare and a Medicare SELECT policy and you move out of its service area | Plan A, B, C*, D*, F* or G* | 60 days before the policy ends, or no more than 63 days after |
| Your Medigap insurer goes bankrupt, your coverage ends through no fault of your own, or the company misled you or broke the rules | Plan A, B, C*, D*, F* or G* | no more than 63 days after coverage ends |
*Plans C and F are closed to people new to Medicare on or after 1 January 2020 — see below.
Look at what these have in common: almost every one is triggered by coverage you already had ending through no fault of your own. Simply changing your mind is not on the list. That is what the two trial rights are for, and they are bounded at twelve months. Both of them.
The 63 days
Nearly every route above ends at 63 days after coverage ends, with the option to start 60 days before. This is the single most consequential number on the page. It is short, it is not extended for not knowing about it, and it starts from a date set by someone else’s paperwork.
If you receive a notice that a plan is leaving your area or your employer coverage is ending, that notice is the start of a clock. Keep it.
Plans C and F, and why the list says A, B, C*, D*, F*, G*
“Plans C and F are no longer available to people new to Medicare on or after January 1, 2020. However, if you were eligible for Medicare before January 1, 2020, but haven’t yet signed up, you may be able to buy Plan C or Plan F. People new to Medicare on or after January 1, 2020, have the right to buy Plan D or G instead of Plan C or F.”
So for most people reading this the practical guaranteed-issue menu is A, B, D or G. What Plan G actually covers.
Outside all of this
You can still apply for a Medigap policy at any time. You are simply subject to medical underwriting, which means the insurer may ask about your health, charge more, or decline. In a minority of states that is not the whole story — the 51-state table shows which ones add annual rights, and what those rights actually let you switch to.
General information drawn from Medicare, CMS and state insurance-department publications, not insurance advice. Medicare rules, plan availability and dollar figures change every year, and state rules differ. Every figure here is year-labelled and every source is named so you can check it against your own situation. We do not sell insurance and receive nothing if you buy a plan.
The assumption that makes this expensive. Leaving Advantage does not entitle you to a Medigap policy — it is the most costly open-enrollment mistake and the latest-discovered: Medicare open-enrollment mistakes.