Medigap Open Enrollment Period 2027: When It Starts and Why It Matters

Reviewed by Russell Noga, Licensed Medicare Insurance Broker (all 50 states) — Last updated October 14, 2026

The Medigap Open Enrollment Period is the most important date on your Medicare calendar, and most people don’t know it exists. It’s a one-time window when any carrier has to sell you a Medicare Supplement plan, whatever your health. Miss it, and getting a Medigap plan later can mean health questions, higher rates, or a flat no.

Here’s how the window works in 2027, when yours starts, and what to do if you’ve already missed it.

Confused by the fall enrollment window? See Medicare Open Enrollment 2027 for the October 15 to December 7 dates and what they mean for Medicare Supplement plans.

During those 6 months, you get guaranteed acceptance:

• A carrier must sell you any Medigap plan it offers in your state.
• It can’t ask health questions to turn you down.
• It can’t charge you more because of your health. You get the same price as someone in perfect health.

That’s why this is the best time to lock in a plan like Plan G or Plan N.

Your window ends 6 months after it starts. Applying a few months early is fine. Many carriers accept applications up to 6 months before your Part B start date.

This trips up a lot of people. The Annual Enrollment Period (October 15 to December 7) is for Medicare Advantage and Part D drug plans. It is not a Medigap enrollment period.

You can apply for a Medigap plan any day of the year. Outside your one-time Medigap Open Enrollment Period, though, most carriers can ask health questions and decide whether to accept you. There’s no fall “reset” that gives you guaranteed acceptance again.

Even during open enrollment, a carrier can sometimes make you wait up to 6 months before it covers a pre-existing condition. That only applies if you didn’t have creditable health coverage for at least 6 months before you enrolled.

If you’re coming off employer coverage or another qualifying plan with no long gap, that wait is usually shortened or removed altogether.

If your 6 months have passed, you still have options:

• Federal guaranteed issue rights. Certain events give you the right to buy specific Medigap plans without health questions, for example losing employer group coverage or your Medicare Advantage plan leaving your area. Time limits apply, usually 63 days.
• The Medicare Advantage trial right. If you joined Medicare Advantage when you first got Medicare and leave within 12 months, you can usually go back to Original Medicare and buy a Medigap plan with no health questions.
• State birthday and anniversary rules. Several states let you switch to a Medigap plan with equal or lesser benefits each year around your birthday or policy anniversary.
• Year-round states. New York and Connecticut let you buy a Medigap plan any time without health questions.
• Apply with underwriting. If you’re in good health, you may simply pass the carrier’s health questions. Rules and questions vary by carrier.

Many people pick a $0 Medicare Advantage plan at 65 and find out years later that getting a Medigap plan isn’t guaranteed anymore. If there’s any chance you’ll want Medigap’s freedom to see any doctor, your open enrollment window is the time to get it.

Compare both paths in our Medicare Supplement vs Medicare Advantage 2027 guide, and see every plan side by side in the Medicare Supplement plans comparison chart 2027.