Medicare Supplement insurance has a 6-month open enrollment period (OEP). It begins as soon as you are both 1) 65 years old and 2) enrolled in both Medicare Part A and Part B (Original Medicare).

Unlike the Medicare OEP that happens once every year, you have only one Medicare Supplement OEP.

If you get Medicare Part B before you turn 65, your Medigap OEP starts the first day of the month you turn 65.

If you delay enrolling in Medicare Part B until after you turn 65, your Medigap OEP automatically starts the month you enroll in Medicare Part B.

Benefits of buying during open enrollment

Purchasing a Medicare Supplement insurance policy during the Medicare Supplement OEP provides several consumer protections. During the OEP, you have the following protections:

  1. Medigap insurance companies cannot deny you coverage.
  2. Insurers cannot increase premium costs because of your health when you purchase your policy.
  3. You are allowed to switch your Medigap insurance policy within your 6-month OEP.
  4. You do not have to wait for coverage to begin (although there may be a waiting period for coverage of a pre-existing condition).

You can apply for a Medigap policy outside of your OEP, but there are fewer consumer protections than if you buy a policy during your OEP. After your OEP has passed, Medigap insurance companies are usually allowed to use medical underwriting, which helps the insurer determine whether or not to accept your application and the policy’s premium. Medical underwriting is not allowed during your open enrollment period.

During their OEP, applicants with poor health have access to the same premiums as healthy applicants. Medicare.gov states that “if you apply during your Medigap open enrollment period, you can buy any Medigap policy the company sells, even if you have health problems, for the same price as people with good health.”

Under-65 open enrollment period

If you are under 65 and qualify for Medigap insurance coverage, you do not have as many consumer protections as over-65 applicants.

Federal law does not require Medigap insurance companies to sell policies to Medicare beneficiaries under the age of 65. Medicare.gov states that if you are under 65, you might not be able to buy your preferred Medigap policy, or any other Medigap policy, until you turn 65. Some state insurance departments extend protections for those under 65, but each state varies, according to the Kaiser Family Foundation. Some states require OEP protection for those under 65, while other states do not.

For more information about getting a Medigap policy during and after your open enrollment period, read our page about buying a Medigap policy.