For those turning 65, when does Medicare start?

That depends on when an individual signs up for Medicare.  Here are different scenarios. 

• Enroll during the first three months of the Initial Enrollment Period and Medicare starts on the first day of the month of the 65^th birthday. (The Initial Enrollment Period begins three months before the birth month and ends seven months later.)
• Enroll during the month of the 65^th birthday or the three months after it and coverage begins one to three months after the birth month.

William and Ron both had birthdays in July. William enrolled in Medicare during the month of his birthday and his coverage started in August, one month after his birthday. Ron waited until October and his coverage didn’t begin until January. There was no late enrollment penalty in these cases.

• Miss the Initial Enrollment Period and the next chance to sign up is during the General Enrollment Period from January 1 through March 31 of the next year. Coverage will begin the first day of the month after enrolling and there may be penalties for enrolling late.