Those turning 65 and still working are eligible for Medicare; however, they are not automatically enrolled because they are not yet receiving Social Security. Instead, they enroll manually during the Initial Enrollment Period.
The seven-month Initial Enrollment Period begins three full months prior to the beneficiary's birthday month and ends three full months after their birthday month. So, someone turning 65 in June is eligible to enroll in Medicare from March through September. After this initial enrollment, the beneficiary's next opportunity to enroll is January 1 to March 31 each year, unless a special enrollment period applies or the beneficiary is applying for free Part A, which is open for enrollment at any time after the Initial Enrollment Period begins.