The yearly period when people can enroll in a health insurance plan. 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. Job-based plans may have different Open Enrollment Periods. Check with your employer. You can apply and enroll in Medicaid or the Children’s Health Insurance Program (CHIP) any time of year.