Open Enrollment Period (OEP)
Definition current for the 2026 plan year · Last reviewed July 2026
In one sentence: The annual window — Nov 1 to Jan 15 in most states — when anyone can buy or switch marketplace coverage.
Open enrollment is the once-a-year window when anyone can enroll in or switch marketplace plans, no questions asked. For 2027 coverage it runs November 1, 2026 – January 15, 2027 on HealthCare.gov; several state marketplaces extend later (California to January 31, for example). Enroll by December 15 in most states for coverage that starts January 1.
It exists to prevent people from waiting until they're sick to buy insurance. Outside the window, you need a qualifying life event or an income under 150% of FPL to enroll — see Missed Open Enrollment.
The single most expensive mistake in 2026: letting a plan auto-renew without re-shopping. Benchmarks and subsidies moved sharply this year, and the plan that was right in 2025 often isn't now. Twenty minutes of comparison each November is the highest-paid work most households do all year.