When you’re first eligible, you have the right to buy any Medicare supplement plan offered in your state. In addition, you generally will get better prices and
more choices among policies. It’s very important to understand your Medigap
Open Enrollment Period. Outside of Medigap Open Enrollment, insurance companies are generally allowed to use medical underwriting to decide whether to accept your application and how much to charge you for your Medicare supplement plan. However, if you apply during your Medigap Open
Enrollment Period, you can buy any Medicare supplement plan the company sells, even if you have health problems, for the same price as people with good health.
If you apply for Medicare supplement coverage after your Open Enrollment Period, there’s no guarantee that an insurance company will sell you a Medicare supplement if you don’t meet the medical underwriting requirements, unless you’re eligible for guaranteed issue rights (Medigap protections) available in limited situations.
It’s also important to understand that your Medigap rights may depend on when you choose to enroll in Medicare Part B. If you’re 65 or older, your Medigap Open Enrollment Period begins when you enroll in Part B, and it can’t be changed or repeated. After your Medigap Open Enrollment Period ends, you may be denied coverage or charged more for a Medicare supplement plan due to past or present health problems.
In most cases, it makes sense to enroll in Part B and buy a Medicare supplement when you’re first eligible for Medicare, because you might otherwise have to pay a Part B late enrollment penalty and might miss your 6-month Medigap Open Enrollment Period. However, there are exceptions if you have employer coverage.