Enrolling in Medicare Part B is a major milestone, but it also starts the clock on one of the most important opportunities in your Medicare journey. From the moment your Part B coverage begins, you enter a six-month window called the Medigap Open Enrollment Period. During this time, you have the right to enroll in any Medicare Supplement (Medigap) plan available in your state. You won’t be asked health questions, and you can’t be denied coverage based on preexisting conditions.
This enrollment period happens only once. And once it ends, the freedom to choose any Medigap plan without restrictions may be gone for good. In this post, we’ll walk you through how this window works, why it matters, and what steps you can take now to protect your future coverage.
What Is the Medigap Open Enrollment Period?
From the moment your Medicare Part B coverage starts, the clock begins ticking.
You get a one-time, 6-month window to enroll in any Medigap (Medicare Supplement) plan available in your state—without any medical questions or risk of denial.
During this time, you can:
- Enroll in comprehensive plans like Plan G or Plan N
- Lock in a premium without being charged more for preexisting conditions
- Avoid health screenings or waiting periods
It’s the most consumer-friendly moment you’ll get. After this 6-month window, your freedom to choose drops sharply.
What Happens After the 6 Months?
Once the window closes, things change:
Most insurance companies will require you to go through medical underwriting—meaning they’ll ask about your conditions, prescriptions, past diagnoses, and hospitalizations.
If your health has changed since you started Medicare? You could be denied outright, or charged significantly more for the same coverage.
And unlike Medicare Advantage plans or Part D drug plans, there’s no annual open enrollment for Medigap. You can apply anytime—but that doesn’t mean you’ll be accepted.
Why It’s a Common (and Costly) Mistake
People often put off choosing a Medigap plan thinking they’ll “figure it out later” or “see how things go.” They might assume that switching plans is as easy as it is with other types of insurance.
But this assumption creates one of the most common regrets we hear: “I didn’t know I’d have to qualify again later.”
Maybe your health is fine today. Maybe you don’t need frequent care. But if that changes—and it often does—your options could vanish. You may be stuck in a plan that no longer meets your needs or stuck without any supplemental coverage at all.
Yes, Some States Have Extra Rules—but Don’t Rely on Them
A handful of states have special switching rules that let you change Medigap plans without underwriting once a year. But those rights vary widely, and they don’t always allow you to move into more comprehensive plans.
If you don’t live in a state with those protections—or don’t qualify under their specific guidelines—your 6-month window at the start of Part B is still your best opportunity.
This Window Is About More Than Convenience—it’s About Peace of Mind
Medigap plans were designed to work alongside Original Medicare, covering the costs that A and B don’t—like deductibles, coinsurance, and excess charges.
The right Medigap plan can help you:
- Predict your medical expenses
- Avoid surprise bills
- See any Medicare-approved doctor in the country
- Bypass pre-authorizations and referrals
But the easiest time to get one is at the very beginning—not when you need it most.
Get Help Making a Confident Choice
Choosing a Medigap plan during your one-time enrollment window isn’t just about locking in good coverage. It’s about giving yourself flexibility, stability, and peace of mind for years to come. This isn’t a decision you have to rush—but it is one you want to make while the full range of options is still open to you. Once that window closes, the path forward gets narrower, and for some, switching later becomes a lot harder.
If you’re unsure where to begin, or want help making sense of your choices, that’s what we’re here for. You’ve done the work to earn your Medicare benefits, now let’s make sure your coverage works just as hard for you.
Call (800) 864‑8890 or schedule a free 45-minute consultation online. Medicare School meets you right where you are and will help you move forward with clarity and confidence.