If you are already collecting Social Security or Social Security disability, then you will become eligible for Medicare benefits after you have been collect for two years or you have turned 65. Once you become eligible, you will automatically be enrolled in Part A and Part B of Medicare. However, if you do not collect Social Security and you are 65, you will not be automatically enrolled. You can still receive Medicare, but you must apply on your own. To receive Medicare Part D, which covers a portion of your prescription drugs, you must apply, even if are collecting Social Security.