01
Initial Enrollment Period
7 months around your 65th birthday
Starts 3 months before the month you turn 65, includes your birthday month, and runs 3 months after. For many people it's the first and simplest window to sign up for Part A and Part B.
JFMAMJJASOND
Moves with your birthday, so see the explainer below.
02
Annual Election Period
October 15 – December 7
The yearly window to join, switch or drop a Medicare Advantage plan or a Part D drug plan. Changes generally take effect January 1.
JFMAMJJASOND
Also called Open Enrollment or the Fall window.
03
Medicare Advantage Open Enrollment
January 1 – March 31
For people already in a Medicare Advantage plan: a chance to switch to a different Medicare Advantage plan or go back to Original Medicare (and add a drug plan).
JFMAMJJASOND
Generally one change during this window.
04
Special Enrollment Periods
Triggered by a qualifying life event
Moving out of your plan's area, losing employer coverage, and certain other events can open a limited window outside the usual dates. Length and rules depend on the event.
JFMAMJJASOND
Can happen any month. Documentation may be required.
05
General Enrollment Period
January 1 – March 31
For people who didn't sign up for Part A or Part B when first eligible and don't qualify for a Special Enrollment Period. Coverage generally starts the month after you sign up.
JFMAMJJASOND
Late-enrollment penalties can apply in some cases.