Attention Trading Partners: MIHMS Upgrade October Payment Cycle Changes and System Access Limitations
As previously communicated, the Office of MaineCare Services (OMS) is preparing to launch an upgraded version of MIHMS, MaineCare’s claims processing system. The upgrade is currently scheduled to go live on October 10, 2026. To support a smooth transition, OMS must implement temporary system access limitations and adjustments to payment cycles in October.
From Friday, October 2 at 8:00 PM until Monday, October 12 at 8:00 AM, MIHMS will be in a “data freeze” while OMS completes final system readiness and transition activities.
Changes to October payment cycles:
Review this information and plan billing accordingly to prepare for the transition.
| Payment Cycle Date | Payment Impact | Claim Submission Deadline for Inclusion in Payment Cycle* |
|---|---|---|
| Wednesday, 9/30/26 | Last regular payment before the data freeze | Friday, 9/25/26, 5:00 AM |
| Thursday, 10/1/26 | Extra payment before the data freeze | Wednesday, 9/30/26, 5:00 AM |
| There will be no payment on Wednesday, October 7. | ||
| Thursday, 10/15/26 | First payment after data freeze, in upgraded system |
Secure File Transfer Protocol (SFTP) submission: Continuous through data freeze up to Tuesday, 10/13/26, 2:00 PM Portal submission: Before data freeze: Friday, 10/2/26, 7:59 PM After data freeze: Tuesday, 10/13/26, 2:00 PM |
| Wednesday, 10/21/26 | Regular payment, in upgraded system | Friday, 10/16/26, 5:00 AM |
*As always, timely submission does not guarantee that the claim will process in time for the next payment cycle. OMS may take up to 30 days to process and pay a claim, depending on any edits or issues that may cause the claim to pend for manual review, as well as other processing requirements that may require the full 30-day timeframe.
Non-claims payments:
By September 1, OMS will communicate with any providers expecting non-claims payments that may be affected by the schedule described above.
Preparing for the changes to October payment cycles:
Beginning September 1, 2026 7:00 AM, OMS will return the HealthPAS Online Portal to its previous regular operating hours. Providers will again have 24/7 access to the portal, for additional flexibility and time to submit claims outside of standard business hours.
We strongly encourage providers to submit claims approaching timely filing limits in the next few weeks to avoid potential submission delays. The planned data freeze does not modify existing Medicaid timely filing requirements. Providers remain responsible for ensuring claims are submitted within the established timely filing guidelines.
Other system access limitations:
Providers can find other expected impacts of the data freeze in this FAQ. Topics include:
- HealthPAS Online Portal, including impacts on submitting claims, submitting prior authorizations, and checking member eligibility
- Provider Enrollment Application (PEA)
- Value-Based Purchasing Management System (VMS) Portal
- Paper & fax document submissions
- Provider Services & Member Services call centers
- Value Added Network (VAN) Trading Partners
- Prior authorizations for prescriptions and behavioral health services
- Electronic Visit Verification (EVV)
You can also check the OMS Provider Resources webpage, in the first box of information called “Health PAS Online Portal,” for the most recent information about the upgrade.
For questions or clarifications, please contact Provider Services at 1-866-690-5585. Please note, Provider Services does not have additional information beyond what is shared in this message and in the FAQ linked above.