"...When you apply for retirement or disability benefits from Social Security (or the Railroad Retirement Board), it also serves as your application for Medicare. Once you get approved for Social Security or Railroad Retirement Board benefits, you’ll automatically get Part A coverage (without having to pay a premium for it) once you’re eligible for Medicare.
If you’re getting benefits from Social Security (or the Railroad Retirement Board) at least 4 months before you turn 65, you’ll automatically get Part A coverage. You’ll also be signed up for Part B (unless you live in Puerto Rico or outside the U.S.). Because you pay a monthly premium for Part B coverage, you can choose whether to keep it or not. ..."
