The Medicare Open Enrollment Period begins on the first day of the month in which you are both 65 years of age (or older) and you are enrolled in Medicare Part B.  This period lasts 6 months.  When did your period begin?  Look at your Medicare card to see when Medicare did/will start.  During the open enrollment is the best time to purchase a medicare supplement.  Often people get confused regarding the terms medicare supplement and medigap.  Medicare supplement and medigap refer to exactly the same type of insurance policy and are therefore synonomous.  This is the best time to purchase a medicare supplement because an insurance company cannot turn you down, apply any conditions, or charge more due to a health problem.  Insurance companies can apply a waiting period for pre-existing conditions to your medigap policy, but that can be eliminated or shorten if you have had prior credible coverage.  Most seniors start Medicare Part B when they turn 65, so for most seniors this is the best time to purchase a Medicare Supplement.