Nundina › Discover calendars › Health Insurance Open Enrollment calendar › 🏥 ACA Marketplace Open Enrollment Begins🏥 ACA Marketplace Open Enrollment Begins1 November 2026Healthcare.gov federal Marketplace Open Enrollment Period for 2027 coverage begins. Verified via CMS "2025 Marketplace Integrity and Affordability Final Rule" (cms.gov), 2026-07.Health Insurance Open Enrollment calendarMore from this calendar