Initial Enrollment Period - When you're turning 65, you have a seven-month period to sign up for Part A and/or Part B. This Initial Enrollment Period begins three months prior to the month you turn 65, and ends three months after the month you turn 65. The date you sign up determines the effective date your Medicare coverage starts.
General Enrollment Period - If you're not enrolled in Medicare, you have the opportunity to sign up for Part A and/or Part B during a three-month period each year. The General Enrollment Period begins January 1 and ends March 31. Your coverage begins the following July 1.
Special Enrollment Period - If you and/or your spouse are currently working and covered by an employer group health plan from that current employer, you may be eligible to sign up for Part A and/or Part B during a Special Enrollment period. Contact the SSA for more information.