Frequently Asked Questions About Medicare Enrollment & Disenrollment Learn how to start getting Medicare, including the different parts of Medicare, and how to disenroll. What is the Medicare Special Enrollment Period (SEP) for the Working Aged? When can I add Part B to my Medicare? Can I delay Medicare Part B enrollment without paying higher premiums? Can I drop Medicare Part B and add it later if I have employer group health insurance? Do I need to enroll in Part B if I am a retired Federal employee with a FEHB plan? How much is the late enrollment penalty? I have Medicare now; do I need to do anything else? How often can I change Medicare plans? Is Medicare Part D optional?