There are a few things to know about opting into Medicare Part B. First, if you're already receiving benefits from Social Security or the Railroad Retirement Board, you will automatically be enrolled in Part B. If you're not already receiving these benefits, you can sign up for Part B during your Initial Enrollment Period, which begins three months before your 65th birthday and ends three months after your birthday. You can also sign up for Part B if you're under 65 and have a disability, or if you have End-Stage Renal Disease.
If you decide not to enroll in Part B when you're first eligible, you may have to pay a late enrollment penalty unless you have other creditable coverage (coverage that's as good as Medicare's).
To sign up for Part B, contact your local Social Security office or call 1-800-772-1213 (TTY users 1-800-325-0778).