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The Mississippi Medicaid MMIS Replacement Project

The Mississippi Medicaid MMIS Replacement Project

The Mississippi Division of Medicaid (DOM) is working with a vendor to develop a new Medicaid Management Information System (MMIS) to replace the aging Envision system, which has been in use for many years.

Click here to search for your Provider ID in MESA

The new provider-enrollment and claims-processing solution is called MESA: Medicaid Enterprise System Assistance, and the agency’s goal is for this modernization to enhance connections between health services systems and improve access to health information for our Medicaid providers and the members they serve.

The new system – MESA – is expected to go-live later in 2022, replacing outdated technology with a more efficient version that is easier to maintain. Recognizing how critically important it will be to ensure a smooth transition, DOM is focused on providing clear information and resources over the coming months to help all providers prepare for the switchover.

Although it will be an adjustment, MESA will allow for some distinct advantages over the current system. For example, a new and improved provider portal will allow for a streamlined provider-enrollment process. Healthcare providers will be able to submit and adjust claims in real-time for each claim type and submit batches of transactions, as well as verify a patient’s eligibility status quickly and easily. The new system will also allow for a centralized credentialing process, eliminating the need for providers to credential with DOM and each coordinated care organization.


Latest Updates

As the new system gets closer to go-live, the latest updates and news notices will be posted here, including information on how providers can test Electronic Data Interchange (EDI) transactions. 


IMMEDIATE ACTION REQUIRED: Medicaid Providers must follow instructions for EDI registration and testing to prepare for new Provider Portal

– Published Aug. 3, 2022

The Mississippi Division of Medicaid (DOM) is in the process of implementing a new Medicaid Management Information System (MMIS) – which will include a new Provider Portal – known as MESA: Medicaid Enterprise System Assistance. The new system, going live at the beginning of October, is being developed by Gainwell Technologies. Read more.

Medicaid providers can now register for MESA workshop webinars

– Published July 22, 2022

As part of the Mississippi Division of Medicaid’s (DOM) transition to a new Medicaid Management Information System (MMIS), we are excited to announce a series of workshop webinars will be available in August and September to train providers in how to use the new system, MESA. Read more.

Suspension of Provider Enrollments

– Published July 19, 2022

The Mississippi Division of Medicaid (DOM) requests that all providers currently planning to enroll as a Mississippi Medicaid Provider submit their application and all supporting documentation no later than Aug. 15, 2022. Read more.

Providers to be informed of changes to Medicaid Provider IDs

– Published June 1, 2022

As part of the Mississippi Division of Medicaid’s (DOM) transition to a new Medicaid Management Information System (MMIS), important changes are on the way involving Medicaid Provider IDs. Beginning June 1, 2022, all actively enrolled Medicaid providers will receive letters in the mail detailing changes that will be made to their Provider IDs. Read More. 


Updated June 17, 2022


Electronic Data Interchange (EDI) Technical Documents

In preparation for go-live, each DOM trading partner must undergo Electronic Data Interchange (EDI) testing to ensure the integrity of electronic transactions. EDI testing will begin in the coming months, and trading partners will need to register to be able to test EDI submissions to MESA. Click on the button below to find preliminary Companion Guides, which describe the specific technical and procedural requirements for interfaces between DOM and its trading partners.

Click here to find Companion Guides