For 2027 coverage on HealthCare.gov, open enrollment runs November 1, 2026 through January 15, 2027. CMS confirmed those dates in a July 27, 2026 statement.

Two deadlines matter inside that window:

  • Enroll by December 15 and your coverage starts January 1.
  • Enroll December 16 through January 15 and coverage starts February 1.

A shortened window ending December 15 was finalized in a 2025 rule, but a federal court vacated that provision in June 2026. The full window is what is in effect. Some state-run exchanges set their own dates. Covered California runs through January 31. Idaho is the outlier and runs October 15 through December 15.

Employer plans and Medicaid follow different calendars. Medicaid and CHIP have no open enrollment at all. You can apply any time of year.