General enrollment period for Medicare, Part B

If you did not apply for Medicare Part B (medical insurance) within three months before or after turning age 65, you have another chance each year during the General Enrollment Period, which runs from January 1 to March 31 each year.  

If you don’t enroll in Part B when you’re first eligible for it, you may have to pay a late enrollment penalty for as long as you have Part B coverage. Your monthly premium will increase 10 percent for each 12-month period that you were eligible for Part B but did not sign up for it.  Your coverage starts the first day of the month after you sign up.