Social Security will mail your Medicare card to you about three months before your 65th birthday. If you're receiving Social Security disability benefits, you will automatically get a Medicare card in the mail after you have received benefits for 24 months. If you're retired and are not receiving Social Security benefits during the three months before you turn 65, you will need to apply for Medicare. To do so, contact any Social Security Administration office. Be sure to apply three months before you turn 65.
Timing is very important in enrolling.
If you are retired, a seven-month initial enrollment period begins three months before you turn 65. By applying early, you'll avoid a possible delay in the start of your Part B coverage. If you don't enroll during this seven-month period, you will have to wait to enroll during the next Medicare general enrollment period, which is held January 1st to March 31st of each year. Part B coverage starts the following July 1st. You may be subject to a Medicare Part B penalty if you enroll late.