Also called: IEP, SEP, GEP, Initial Enrollment Period, Special Enrollment Period, General Enrollment Period
You first sign up during a seven-month window around your 65th birthday. If you keep working with employer coverage you can sign up later without penalty, within eight months of that coverage or job ending.
The Initial Enrollment Period runs from three months before the month you turn 65 to three months after it. The Special Enrollment Period applies only to coverage based on current employment, yours or your spouse's. COBRA and retiree coverage do not count.
If you miss both, you wait for the General Enrollment Period, January 1 to March 31 each year, with coverage starting the month after you sign up, and late penalties may apply.