What is 'open enrollment' in health insurance?

Open enrollment is a designated period during which individuals can sign up for health insurance or make changes to their coverage (such as switching plans). Outside of open enrollment, a person generally can enroll or change coverage only if they experience a qualifying life event — such as marriage, birth of a child, or loss of other coverage — which triggers a special enrollment period. Open enrollment periods help insurers manage risk by limiting when healthy and sick individuals can join, reducing adverse selection. Understanding open enrollment and special enrollment periods is standard content, though specific dates and rules can change.