If you are not collecting Social Security, you are not automatically enrolled onto Medicare. You can enroll online (www.ssa.gov) or contact Social Security (800-772-1213) in the 4th month before your birthday to enroll effective your 1st of your birthday month. Once you are enrolled onto Part A (hospital benefit) and Part B (outpatient services), you can, in the 3 months prior to your birthday month, enroll onto the Medicare insurance of your choice; i.e., a Medicare supplement/medigap policy and a stand-alone drug plan /or/ a Medicare Advantage/HMO plan. The insurance you select will be effective the 1st of your birthday month. You can also make your election during your birthday month, to be effective the 1st of the following month. In addition, you can make your selection during the 3 months following your birthday month.
You can delay without a penalty your Part B if you are currently work for an employer, typically one of 20+ employees.
If you aren’t working and miss your 7 month election period, then you can only sign up for Part A until the next special election period for Part B which will be January 1st through March 31st of the following year. You will then be assessed a 10% penalty for the delay in enrollment.