When Is The Medigap Open Enrollment Period? 
Under Federal law when you first enroll in Medicare Part B at age 65 or older , you have a guaranteed right to buy a Medicare Supplement policy for six months . Your acceptance is guaranteed and pre-existing health conditions are covered immediately . After your Open Enrollment period is over you can apply for a Medicare Supplement later at any time , but you may be charged a higher rate or be denied coverage if you have serious health conditions . This may be your only chance to get a Medicare Supplement without having to go through medical underwriting . It is very important that you choose wisely during your Open Enrollment Period because the wrong Medicare Health Plan could end up costing you thousands of dollars for Medicare approved services and may keep you from seeing the doctors and hospitals you want to go to . 