What Is the Medigap Open Enrollment Period?

Health Line

16-06-2025

The Medigap open enrollment period (OEP) is your first opportunity to enroll in a Medigap plan. During the Medigap OEP, you cannot be denied Medigap coverage due to a preexisting health condition.
Medicare supplement insurance, or Medigap, is a type of private insurance that helps cover the out-of-pocket costs of Original Medicare.
As with other parts of Medicare, Medigap has a set enrollment period for people new to Part B.
In this article, we discuss the Medigap open enrollment period, its benefits, and what happens if you miss this window.
When is the Medigap open enrollment period?
The Medigap OEP is a one-time, 6-month window that begins on the first of the month you are enrolled in Part B and are age 65 years or older.
If you sign up for Medigap during the Medigap OEP, you can join any plan in your state. Additionally, insurers cannot deny you coverage or charge you a higher rate due to a preexisting health condition.
If you wait until after the Medigap OEP to join a plan, insurers are under no obligation to sell you a plan or charge you the standard rate.
Insurers can evaluate factors like your medical history and age when deciding whether to sell you a plan. This process is known as medical underwriting.
The Medicare website has a tool you can use to determine when and whether you're eligible to enroll in Medigap.
Benefits of the Medigap open enrollment period
If you're considering joining a Medigap plan, there are various benefits to doing so during the Medigap OEP instead of waiting. These include the following:
You can join any plan in your state regardless of your health status.
You'll have access to a wider array of plan options at lower costs.
Your coverage will begin immediately (with the exception of expenses related to preexisting conditions, which are subject to a 6-month waiting period before the Medigap policy starts covering them).
What happens if I miss the Medigap open enrollment period?
As mentioned earlier, if you miss the Medigap OEP, you could be subject to medical underwriting when you try to enroll in a Medigap plan, resulting in fewer options and higher costs.
However, there are situations where this may not apply, known as 'guaranteed issue rights.' These rights apply in certain cases where a person loses coverage or experiences a change in coverage.
If you have guaranteed issue rights, an insurance company needs to sell you a Medigap policy, regardless of whether you have a preexisting condition, and they can't charge you more due to your health status.
Some circumstances where guaranteed issue rights might come into play include:
losing Medicare Advantage coverage due to:
your plan leaving Medicare
your plan leaving your area
you moving out of the plan's area
losing secondary insurance through an employer while enrolled in Original Medicare
losing coverage due to the bankruptcy of your Medigap provider
Some states have different Medigap rules. If you have questions about Medigap open enrollment in your specific state, consider reaching out to your local State Health Insurance Assistance Program (SHIP).
Frequently asked questions
How long is open enrollment for Medigap?
Open enrollment for Medigap lasts 6 months. If you're age 65 years or older, the Medigap OEP begins on the first of the month that you have Part B coverage.
Open enrollment for Medigap lasts 6 months. If you're age 65 years or older, the Medigap OEP begins on the first of the month that you have Part B coverage.
Can I add a Medigap policy at any time?
Yes, you can sign up for a Medigap policy at any time. Unlike Medicare Advantage plans, which require waiting for specific enrollment periods to join, switch, or drop coverage, you don't need to wait for a set enrollment period with Medigap.
However, if you sign up for a Medigap plan outside of the Medigap OEP, insurance companies are free to deny you coverage or charge you a higher rate based on your health.
Yes, you can sign up for a Medigap policy at any time. Unlike Medicare Advantage plans, which require waiting for specific enrollment periods to join, switch, or drop coverage, you don't need to wait for a set enrollment period with Medigap.
However, if you sign up for a Medigap plan outside of the Medigap OEP, insurance companies are free to deny you coverage or charge you a higher rate based on your health.
Summary
The Medigap open enrollment period (OEP) is a 6-month window that starts at the beginning of the month when you're age 65 years or older and first have Part B.
During the Medigap OEP, you can buy any Medigap plan offered in your state regardless of whether you have a preexisting health condition.