Here's the short answer. Your Medigap Open Enrollment Period is a one-time, 6-month window. It starts the first day of the month you are 65 or older and signed up for Part B. After it ends, there is no federal guarantee that a company will sell you a Medigap policy. If you can buy one, it may cost more because of past or present health problems. A few situations give you "guaranteed issue rights." They let you buy a policy even after your open enrollment window has passed.
The Medigap Open Enrollment Period
This is the best time to buy a Medigap policy. You get one such window, and it lasts 6 months.
- You must have Part B. You cannot buy Medigap until you sign up for Part B.
- You must be 65 or older. The window starts the first month you have Part B and are 65 or older.
- Working past 65? If you delay Part B because of employer coverage, your window does not start until you get Part B. See Working Past 65.
- Under 65? Federal law generally does not require companies to sell Medigap to people under 65. Some states do.
- Some states add more windows.
Missing this window does not end your coverage. It only means you may face health questions later. For how that works, see Medigap underwriting.
Guaranteed issue rights: when you can still buy
Guaranteed issue rights are special chances to buy Medigap outside your open enrollment window. Medicare's own tool lists these main situations.
| Your situation | What Medicare says |
|---|---|
| Your Medicare Advantage plan is leaving Medicare, or you move out of its area | You can switch to Original Medicare and buy a Medigap policy. Apply from 60 days before your coverage ends to no more than 63 days after. |
| Your Medicare Advantage plan did not follow the rules or misled you | The same rights and 60-day-before to 63-day-after timing apply. |
| You joined a Medicare Advantage plan when first eligible at 65 and switch to Original Medicare within the first year | You can buy certain Medigap policies sold in your state. |
| You dropped Medigap to join a Medicare Advantage plan for the first time | You get a 12-month "trial right" to get a Medigap policy back. If the same company still sells your old policy, you can buy it. |
| You lost your Medigap coverage through no fault of your own, such as a company that went bankrupt | You can buy Plan A, B, C, D, F, G, K, or L sold in your state. You have 63 days after your coverage ends. |
| You lost other health coverage | You may be able to buy a Medigap policy. Call your SHIP to see if you qualify. |
Your rights may last an extra 12 months in certain cases. The details depend on your state and your situation, so confirm yours with your SHIP.
The 63-day deadline
Most guaranteed issue rights come with a short clock. For many of them, you have 63 days after your old coverage ends to apply. Do not wait. Keep every letter, notice, email, and claim denial from your old plan. You may need to send copies with your new application to prove your coverage ended.
What does not change
- You still need Original Medicare. If you have a Medicare Advantage plan, it is illegal for anyone to sell you a Medigap policy unless you are switching back to Original Medicare.
- Medicaid usually blocks a sale. Companies generally cannot sell you Medigap if you have Medicaid.
- Plans C and F may be closed to you. If you became eligible for Medicare on or after January 1, 2020, you cannot buy Plan C or Plan F. See Plan G vs. Plan N for the plans many newer enrollees compare.
- Medigap covers one person. Spouses must buy separate policies.
Coverage starts the first of the month after you apply, unless you ask for a later date.
A short action list
- Find your date. Write down the day your Part B starts or your old coverage ends.
- Count your window. Six months for open enrollment. Sixty-three days for most guaranteed issue rights.
- Gather proof. Keep your plan letters and notices.
- Call your SHIP. It gives free, unbiased help and has no tie to any insurer.
- Read the related guides. See when your plan is ending and switching to Original Medicare.
Common questions
Can I get a Medigap open enrollment period more than once?
No. It is a one-time, 6-month window that starts when you have Part B and are 65 or older. Guaranteed issue rights are separate and apply only in certain situations.
What is a guaranteed issue right?
It is a right to buy a Medigap policy outside your open enrollment window, in certain situations such as your Medicare Advantage plan leaving Medicare.
How long do I have to buy after my coverage ends?
For many guaranteed issue rights, you have 63 days after your old coverage ends. Some rights also start up to 60 days before.
Can a company turn me down after my open enrollment ends?
There is no federal guarantee that a company will sell you a policy outside your open enrollment window or a guaranteed issue right. Your state may have more protections.