The Medigap Open Enrollment Period: Why You Only Get One Shot

# The Medigap Open Enrollment Period: Why You Only Get One Shot

In Florida, missing your Medigap Open Enrollment Period can lock you out of the best Medicare Supplement plans permanently — here's exactly when it happens.

Author: Lynsey Brennan, Licensed Medicare Advisor | Published May 27, 2026 Reading time: 5 min read

Quick Answer

Your Medigap Open Enrollment Period lasts six months starting the first day of the month you turn 65 and enroll in Medicare Part B. During this window, insurance companies cannot turn you down or charge you more for pre-existing conditions — but once it closes, you'll face medical underwriting for most plans, and many people can't qualify.

Table of Contents

• What Actually Happens During Medigap Open Enrollment
• When Your Six-Month Window Opens (and Closes)
• What Medical Underwriting Means After Your Window Closes
• Florida-Specific Rules You Need to Know
• The One Exception: Switching to Plan A or Plan F
• Why People Miss This Window
• Your Best Move If You're Still in Your Window

What Actually Happens During Medigap Open Enrollment

For six months, every Medigap carrier selling in Florida has to accept you at standard rates regardless of your health. You could have diabetes, heart disease, or ongoing cancer treatment — doesn't matter. They take you, and they charge you the same rate they'd charge someone with perfect health.

This is federal law under Section 1882(s)(2) of the Social Security Act. After those six months? That protection disappears.

I've watched people delay a Medigap decision by two months because they wanted to "think about it," then find out they're uninsurable when they finally apply. A Plan G that would have cost $145 per month in Palm Beach County becomes unavailable at any price.

When Your Six-Month Window Opens (and Closes)

Your clock starts the first day of the month you're both 65 or older AND enrolled in Part B. Here's where people get tripped up:

If you turn 65 in July but delay Part B until October because you're still working, your window doesn't start until October 1st. It ends March 31st of the following year.

If you're already on Medicare before 65 (disability, ALS, or ESRD), you don't get this protection until you actually turn 65. Some people assume their years on Medicare count — they don't.

Mark your calendar for the exact end date. Applications received after that date go through underwriting, even if you started the application before the deadline.

What Medical Underwriting Means After Your Window Closes

Medical underwriting is the process where insurance companies review your health history and decide whether to accept you and what to charge. In Florida, most Medigap carriers will decline you or charge significantly higher premiums if you have:

• Insulin-dependent diabetes
• Congestive heart failure or COPD
• Cancer treatment in the past 5-10 years
• Kidney disease or dialysis
• Most autoimmune conditions
• Even well-controlled conditions like atrial fibrillation

Some carriers use a simple yes/no questionnaire. Others request full medical records. I've seen people who take two daily medications get declined, and I've seen people with serious conditions get approved at higher rates. There's no consistency, which is exactly why you don't want to gamble on it.

According to 2025 CMS data, roughly 35% of applicants over 65 who apply for Medigap outside their Open Enrollment Period are declined coverage.

Florida-Specific Rules You Need to Know

Florida is not a guaranteed-issue state for Medigap. Some states force carriers to accept you during annual periods — Florida doesn't. Your six-month window is it.

With over 280,000 Medicare beneficiaries in Palm Beach County alone, I regularly meet people who moved here from states with more protections and assume Florida works the same way. It doesn't.

Florida does require carriers to offer you a Medicare SELECT plan (a Medigap plan with network restrictions) during Open Enrollment, but after that window, SELECT plans also require underwriting.

One thing Florida does right: birthday rule. If you already have a Medigap plan, you can switch to a same-level or lower-benefit plan within 60 days of your birthday each year without underwriting. But you have to already own a plan — this doesn't help you get your first one.

The One Exception: Switching to Plan A or Plan F

Florida law requires carriers to offer Plan A year-round without medical underwriting if you already have a different Medigap plan. Plan A covers the least — just the Medicare Part A deductible and coinsurance. It's rarely worth buying.

If you were eligible for Medicare before January 1, 2020, you can also switch to Plan F without underwriting, but only if you already own a different Medigap plan. This doesn't help first-time buyers.

These exceptions sound useful but help almost no one in practice.

Why People Miss This Window

The most common reason: they enroll in a Medicare Advantage plan at 65, don't like it, and want to switch to Original Medicare plus Medigap six months later. By then, the window is closed.

Second most common: they're told "you can always get Medigap later." Technically true if you pass underwriting. Realistically false for many people.

Third: confusion about when Part B started. If you delayed Part B legitimately (through an employer), your window hasn't started yet — but if you just didn't sign up, you're past it.

Your Best Move If You're Still in Your Window

Get at least three quotes from highly-rated carriers. In Palm Beach County, Plan G typically runs $135-165/month depending on the company, your age, and whether you're male or female (yes, gender affects pricing in Florida).

Plan N runs about $15-25 less per month but has copays at the doctor. Plan G has become the standard since Plan F closed to new buyers in 2020.

Don't let anyone rush you into Medicare Advantage just because it has a $0 premium. If you're healthy now and want the freedom to see any doctor without referrals or networks, your Medigap Open Enrollment Period is your chance to lock that in forever.

Frequently Asked Questions

Q: Can I switch from Medicare Advantage to Medigap after my Open Enrollment Period? A: Only if you pass medical underwriting. If you're within your first 12 months on Medicare Advantage and you're still in your six-month Medigap window, you have guaranteed issue rights. After that, you'll need to qualify based on health.

Q: What if I move to Florida from another state after age 65? A: Moving states is not a guaranteed-issue event for Medigap in Florida. You'll face underwriting unless you qualify for a different special enrollment right, like losing employer coverage.

Q: Is the Medigap Open Enrollment Period the same as the Medicare Annual Enrollment Period? A: No. The Annual Enrollment Period (October 15 - December 7) is for changing Medicare Advantage or Part D plans. Your Medigap Open Enrollment is a one-time, six-month window tied to when you first get Part B at