The yearly period when people can enroll in a health insurance plan. 2016 Open Enrollment ended January 31, 2016. Open Enrollment for 2017 runs from November 1, 2016 to January 31, 2017.
Outside the Open Enrollment Period, you generally can enroll in a health insurance plan only if you qualify for a Special Enrollment Period. You qualify if you have certain life events, like getting married, having a baby, or losing other health coverage.