What dates are Medicare Annual Enrollment and what can I change?

Every year from October 15 to December 7, Medicare opens a window where you can make changes to your coverage. Whatever you choose takes effect January 1 of the following year. This is the main time most people review and update their plans. During Annual Enrollment you can switch from one Medicare Advantage plan to another, drop Medicare Advantage and return to Original Medicare, or add and change a standalone Part D prescription drug plan. If you are on Original Medicare with a standalone drug plan, you can swap to a different drug plan or drop it entirely, though dropping without other creditable coverage could mean a penalty later. There is also a separate window called the Medicare Advantage Open Enrollment Period, which runs January 1 through March 31. During that window, people already enrolled in a Medicare Advantage plan can switch to a different Advantage plan or move back to Original Medicare. You cannot, however, use that January window to enroll in Medicare Advantage for the first time if you are currently on Original Medicare. Plan details, premiums, drug formularies, and networks can all change from year to year, so reviewing your Annual Notice of Change, the letter your plan sends each fall, before making any decision is a smart starting point.