Often lost in the variety of widely discussed options for when to best start Social Security payments (As early as 62? As late as 70?) is a key issue: none of that discussion applies to Medicare.
Medicare is a different law with entirely separate sign-up requirements, tied specifically to your 65th birthday. Assuming you are not subject to specific special exceptions (already disabled and drawing Social Security benefits, for example), the law provides a seven-month window for your original Medicare Part A (Hospital Insurance) application:
• The three months prior to the month of your 65th birthday
• The month of your 65th birthday
• The three months following the month of your 65th birthday.
You must apply for Medicare Part A during this window, even if you are not going to apply for Social Security until a later date.
For complete application information, including whether you are also required to sign up for Part B (Medical Insurance) at the same time as Part A, and/or any applicable penalties for failing to do so, go to the Medicare website at www.medicare.gov.