You should end your Marketplace coverage if you become eligible for coverage through an employer or other program, like Medicare, Medicaid, or the Children's Health Insurance Program (CHIP).
Check the date your new coverage will start before ending your Marketplace coverage to make sure you don't have a gap in coverage.
Once you end Marketplace coverage, you can't re-enroll until next Open Enrollment (unless you qualify for a Special Enrollment Period).
You don't need to end your coverage if you're enrolling in a new or different plan during Open Enrollment.