Under the ACA, what is the 'open enrollment period' for marketplace coverage?

ACA marketplace plans have an annual open enrollment period, typically November 1 through January 15 in states using the federal exchange (HealthCare.gov). State-based exchanges may set different periods. During open enrollment, anyone can enroll in or change plans without restriction. Outside open enrollment, enrollment requires a 'qualifying life event' (QLE) that opens a special enrollment period (SEP) — examples: marriage, divorce, birth or adoption of a child, loss of other coverage, moving, change in income affecting subsidy eligibility. SEPs are typically 60 days from the QLE. The structure prevents adverse selection (people waiting until they are sick to enroll). Medicaid and CHIP have year-round enrollment; Medicare has its own annual enrollment periods.