Here are the important dates for Open Enrollment for healthcare.gov Health Insurance plans for 2024: Enroll by 12/15/2023 for a January 1, 2024 start date for your health insurance on healthcare.gov. If you miss the 12/15 deadline, then you still have until 1/15/2024 to enroll for a February 1, 2024 start date. If you don't...