When Is Medicare Open Enrollment for 2026 Plans?

Medicare open enrollment runs annually from Oct. 15 to Dec. 7, allowing changes to Original Medicare, Medicare Advantage, and Part D plans for the following year. Medicare Advantage has a secondary enrollment from Jan. 1 to March 31 for plan switches or reverting to Original Medicare. New enrollees have a seven-month initial period around age 65. Special and guaranteed issue periods allow changes outside these windows under certain conditions.