A Medicare Supplement (Medigap) plan is known as a private supplemental insurance plan that Medicare beneficiaries may choose to purchase separately to reduce the cost of Original Medicare (Part A and Part B).

For most enrollment is a one-time only 6-month enrollment period, typically occurring when a person ages into Medicare at 65 providing new beneficiaries with the guaranteed issue rights to Medigap plans. For individuals receiving Medicare Part B before their 65th birthday their Medigap Open Enrollment Period (OEP) starts the first day of the month they turn 65 as well. If there is an enrollment delay going past turning 65 then the Medigap OEP will automatically start the month of enrolling in Medicare Part B.

Medicare beneficiaries may have additional opportunities or an extended period to enroll in Medigap as some states have state-specific policies and rights that provide additional protection to their residents.

When Does Medicare Supplement Enrollment Start?

The Medigap enrollment period starts on the month you turn 65 and are eligible for Medicare Part B benefits. At this time, insurance companies are required to sell you a policy regardless of any pre-existing conditions.

The rate an insurance company gives you for a quote during this time can only be based on certain factors such as:

  • Age
  • Whether you are a smoker or not.
  • Gender
  • Marital status
  • Where you live.
  • Pre-existing health conditions may not be used to increase the rate during this time.

The Medigap enrollment period ends 6 months after you become eligible for benefits.

Missed the Open Medigap Enrollment Period? The Guaranteed Issue Right May Help

Ideally, the best time to enroll in Medigap is during the first 6 months. Insurance companies cannot deny you and they cannot put restrictions on your policy such as waiting periods or coverage delays. If you don’t enroll during the open period, you may be able to enroll if you have a guaranteed issue right.

A guaranteed issue right means that insurance companies will be required to sell you a Medigap policy at the best rate even though the open enrollment period has passed. During this period, the insurance company also cannot deny coverage for pre-existing conditions or place limitations on when coverage begins.

If you have a guaranteed issue right, you will have 63 days in which to purchase a Medigap policy. To have a guaranteed issue right, you must be 65 or older and eligible for Medicare Part B benefits, you must also experience one of the following:

  • Recently lost a group health plan that provided Medicare cost-sharing – you must have lost the group health plan through no fault of your own.
  • Enrolled in a Medicare Advantage Plan as soon as you became eligible but decided to disenroll within 12 months of enrolling.
  • Coverage from a previous Medicare Advantage Plan, Medicare SELECT or PACE program was discontinued or ended abruptly or it has been discovered there was fraud.
  • Recently moved out of an area where your current Medicare Advantage Plan, PACE program or Medicare SELECT provides coverage.

Want to Enroll Outside of the Medigap Enrollment Period? You Still Can!

The best situation, and the one that will most likely get you the best rates, is to enroll during the open enrollment or if you have a guaranteed issue right. If you want to purchase a Medigap policy outside of the enrollment period, you still might be able to purchase one. However, you might encounter a number of problems or complications.

Some of the complications and issues you may encounter when enrolling outside of the open Medigap enrollment period includes:

  • High rates – insurance companies may now use pre-existing conditions and other factors when giving you a quote which can increase your rates
  • Waiting periods for coverage – you may have a waiting period, such as 6 months, before your Medigap policy starts
  • Denial – insurance companies are not required you provide you with a quote or even provide you with coverage. You can be denied for a number of reasons.
  • Medical restrictions may apply

Paying attention to enrollment periods for Medigap is important as it makes the process easier and could save you money as you get the best rates. However, if you don’t enroll during your unique open Medigap enrollment period, you may still be able to get a Medigap policy. The process may be more complex and your quotes may be higher.


  1. When Can I Buy Medigap?, Medicare.gov.