What is the Medigap Open Enrollment Period?
The Medigap Open Enrollment Period is a one time, 6 month window created by federal law. It begins the first month you meet both conditions: you are 65 or older and you are enrolled in Medicare Part B. During the window you have guaranteed issue rights for every Medigap plan sold in your state. An insurer cannot refuse your application, cannot use medical underwriting, and cannot charge a higher premium because of your health. One caution: if you were treated for a condition in the 6 months before your policy starts and you lacked 6 months of prior creditable coverage, the insurer can delay coverage for that specific condition for up to 6 months. If you keep working past 65 and delay Part B under employer coverage, you do not lose the window. It starts whenever your Part B begins. Just keep the Part B decision on its own calendar, because that side has its own deadlines once your employer coverage ends, and missing them is what triggers a Part B late enrollment penalty.
What happens if you miss your Medigap Open Enrollment Period?
If you miss your Medigap Open Enrollment Period, insurers in most states can medically underwrite you, which means they can deny your application or charge more based on your health. Federal law never extends or repeats the window. You can still get a plan without underwriting if a guaranteed issue right applies. The main ones: you joined a Medicare Advantage plan at 65 and leave within 12 months (trial right), you dropped a Medigap plan for your first Medicare Advantage plan and return within 12 months, your Advantage plan leaves Medicare or your area, you move out of your plan's service area, your employer or union retiree coverage ends, or your Medigap insurer goes bankrupt or misled you. You generally have 63 days from losing coverage to apply, so save every termination letter. Some states add yearly rights on top, covered in the table below.
Is Medigap Open Enrollment the same as the fall Medicare Open Enrollment?
No, and mixing them up is the most expensive mistake in Medicare. The fall Annual Enrollment Period runs October 15 to December 7 every year and lets you change Medicare Advantage and Part D drug plans. It does nothing for Medigap. There is no yearly window in federal law when Medigap plans must accept you. Your Medigap guaranteed issue rights came once, in the 6 months after you turned 65 with Part B. Every fall, people drop their Medicare Advantage plan during AEP assuming a Medigap plan must take them. In most states, that application goes through full medical underwriting, and a heart condition, diabetes with complications, or a recent cancer diagnosis can mean a denial. Before you drop anything during AEP, confirm in writing that a Medigap insurer will accept you.
Can you switch from Medicare Advantage to Medigap during AEP?
You can always leave Medicare Advantage for Original Medicare during AEP, but getting the Medigap plan that makes the switch safe is the hard part. Returning to Original Medicare does not create a right to buy a Medicare Supplement plan. Unless you qualify for a trial right, another federal guaranteed issue situation, or a state rule like New York's year round open enrollment, the Medigap insurer can review your health history and say no. The safe order is: apply for Medigap first, get approved, then disenroll from your Advantage plan. Trial rights help two groups: people who joined Medicare Advantage at 65 and leave within 12 months can buy any Medigap plan in their state, and people who dropped a Medigap plan for their first Advantage plan can reclaim that same policy within 12 months.
Which states give you a yearly chance to switch Medigap plans?
Four of the eleven states where Lara is licensed soften the one window rule. California, Nevada, and Idaho have birthday rules that let current Medigap policyholders switch each year without underwriting, and New York allows enrollment any time. These rules help you switch plans or lower your premium, but in birthday rule states you must already own a Medigap policy, and you can only move to equal or lesser benefits. They do not rescue someone who never bought Medigap in the first place. Here is every state we serve. Rules change: Nevada and Idaho added their birthday rules in 2022, so check your state page or call (818) 472-5484 for current rules.
| State | Yearly switching rule |
|---|---|
| California | Yes. Birthday rule: 60 day window tied to your birthday each year, switch to equal or lesser benefits with any insurer, no health questions. |
| Nevada | Yes. Birthday rule: 60 days from the first day of your birth month, equal or lesser benefits, any insurer. |
| Idaho | Yes. Birthday rule: 63 days from your birthday, equal or lesser benefits, any insurer. |
| New York | Yes, the strongest rule: buy or switch any Medigap plan year round with no underwriting, and premiums never depend on age or health. |
| Texas | No yearly rule. Underwriting applies after your one federal window. |
| Arizona | No yearly rule. Underwriting applies after your one federal window. |
| Florida | No yearly rule. Underwriting applies after your one federal window. |
| Hawaii | No yearly rule. Underwriting applies after your one federal window. |
| Arkansas | No yearly rule. Underwriting applies after your one federal window. |
| Colorado | No yearly rule. Underwriting applies after your one federal window. |
| Michigan | No yearly rule. Underwriting applies after your one federal window. |
Verified August 2026 against medicare.gov, KFF, and state insurance department sources. Rules change; confirm before acting.
Can you get Medigap before age 65?
It depends entirely on your state, because federal law only guarantees Medigap access at 65. If you have Medicare under 65 due to disability, your options in our states vary widely. New York and Hawaii require every plan at the same rates as 65 year olds. Idaho requires all plans with premiums capped at 150 percent of age 65 rates. Nevada made all plans guaranteed issue starting in 2026 with premium caps. Florida and Colorado require all plans but allow much higher premiums. Texas, Arkansas, California, and Michigan require insurers to offer at least some plans, though California excludes people with end stage renal disease. Arizona has no requirement at all. One piece of good news applies everywhere: when you turn 65, you get the full federal 6 month Medigap Open Enrollment Period, with all its protections, no matter what coverage you had before.
Get the timing right the first time
Lara Goulson is an independent insurance agent licensed in California, Nevada, Texas, Arizona, Florida, Hawaii, Idaho, Arkansas, Colorado, Michigan, and New York. She helps you use your one Medigap window, or find a guaranteed issue path if it has passed, at no cost to you. Service in English, Spanish, and Hebrew.
Call or text (818) 472-5484 before you make any change. Timing decides everything with Medigap.
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