MedicaidAdministrativeHigh impact
Managed Care Entity Bulletin 124: Medicaid Management Information System and Provider Online Service Center Migration to Amazon Web Services
MassHealth·MA·Managed Care
Effective date
Mar 14, 2025
We identified it
Jun 18, 2026
Summary
MassHealth is migrating its Medicaid Management Information System (MMIS) and Provider Online Service Center (POSC) to Amazon Web Services from March 14-17, 2025. All billing system access will be unavailable during this migration period, and providers must update their POSC bookmarks to a new URL after March 17th.
Action Required
By March 13, 2025 6:00 PM: Submit all final HIPAA transactions and download necessary 834/820 files before system shutdown. During March 14-17: Use daily 834 files from March 14th and March 17th to validate member eligibility, and continue serving members with valid MassHealth ID cards even if eligibility cannot be verified online. By March 17, 2025 7:00 AM: Update all bookmarked POSC URLs to https://mmis-portal.ehs.state.ma.us/EHSProviderPortal and ensure firewall access for new IP addresses (15.197.248.41 and 35.71.150.175). Notify all staff, vendors, and subcontractors of the migration timeline.