Coverage for Medicare Parts A and B is not automatic. You need to apply for it. You can do that by going to the Medicare website.

• If you retire before or at age 65, it’s best to apply for coverage three months before you turn age 65. You also can apply up to three months after the month in which you turn age 65 without paying a late-enrollment penalty.
• If you continue to work past age 65, it’s best to apply for coverage three months before your retirement month (since the medical coverage you have as an active employee will end at the end of the month in which you retire).