Your one-time Medigap open enrollment: why the six months after Part B matter most

How the federal Medigap open enrollment period works, what guaranteed issue means, and the situations that give you another chance later.

For six months starting the first month you are both 65 or older and enrolled in Part B, you have a Medigap open enrollment period. During it, any insurer selling Medigap in your state must sell you any plan it offers, at its standard price, with no health questions. It does not repeat.

Why it is so valuable

After this window, in most states insurers can ask about your health and decline you or charge more. People who start with Medicare Advantage or Original Medicare alone and later want Medigap often find they cannot get it. Washington and a few other states have extra switching rights (see Washington's rule), but most do not.

Delaying Part B delays the window

If you keep employer coverage and delay Part B, your Medigap open enrollment starts when Part B begins. That is a good thing: you do not waste the window while you do not need it.

Guaranteed issue rights later

Federal law gives guaranteed issue rights in specific situations, including:

• Your Medicare Advantage plan leaves your area or stops serving Medicare.
• You joined Medicare Advantage when first eligible at 65 and want to leave within the first 12 months (the trial right).
• You dropped a Medigap policy to try Medicare Advantage for the first time and leave within 12 months.
• Your employer or union coverage that pays after Medicare ends.
• Your Medigap insurer goes bankrupt or misleads you.

Time limits apply, usually 63 days after the coverage ends. The trial right is explained in detail separately.

A simple rule

If you think you may ever want Medigap, the safest time to buy it is during open enrollment. For a Washington or Florida quote comparison, Maru Insurance's Medicare Supplement page is one place to start.

Questions people ask

How long is Medigap open enrollment?

Six months, starting when you are 65 and enrolled in Part B.

Can I be turned down during open enrollment?

No. Insurers must sell you any plan they offer at standard rates.

Does it happen again?

No, but specific guaranteed issue rights and some state rules allow later purchases.

Does delaying Part B delay the window?

Yes. It starts when Part B begins.

Independent educational site. Not affiliated with or endorsed by the U.S. government, the federal Medicare program, or any insurance company. Figures are 2026 amounts published by CMS unless noted; check Medicare.gov for your situation.