MPRIME Goes Live in October: The December 31 Deadline That Decides Whether You Get Paid for This Fall

You hired a therapist in July. Good candidate, licensed, ready to work. Credentialing opened ePREP to add her and found the door closed. Not a backlog, not a slow queue: the system would not accept the application at all.

So she started seeing clients anyway, because the referrals were there and the alternative was paying her to wait. It is now late September. She has roughly ten weeks of sessions behind her, none of them billed, and nobody in the building can say with confidence whether that revenue is recoverable.

It probably is. But it is recoverable on a deadline, and the deadline is December 31.

What is actually happening

Maryland Medicaid is replacing ePREP, the enrollment and revalidation portal every provider in the state has used for years, with a new system called MPRIME, the Maryland Provider Registration and Information Management Enterprise. Go live is October 2026.

To clear the decks for the migration, MDH stopped accepting applications in ePREP in two waves, by provider risk tier (PT 59-26, January 29, 2026):

• July 1, 2026: applications closed for high and moderate risk provider types.
• August 1, 2026: applications closed for limited risk provider types.

Anything submitted after your tier's date gets returned without processing. That covers new enrollments, revalidations, and any change to an existing record.

Behavioral health is split across both waves, which is why practices with more than one program have had two different experiences of the same policy. From the transmittal's own attachments:

Closed July 1 (high and moderate risk): Outpatient Mental Health Clinic (PT MC), Psychiatric Rehabilitation Services Facility (PT PR), Substance Use Disorder Program (PT 50), Mobile Treatment Program (PT MT), Behavioral Health Crisis Stabilization Center (PT CF), Community Based Partial Hospitalization (PT MH), IMD Residential SUD Adult (PT 54), Intermediate Care Facility Addiction for recipients under 21 (PT 55), Residential Intervention Services (PT GI), Drug Clinic (PT 32).

Closed August 1 (limited risk): Mental Health Case Management (PT CM), Case Management Not Elsewhere Classified (PT 81), Mobile Crisis Team (PT MS), Supported Employment (PT SE), Certified Community Behavioral Health Clinic (PT CB), Mental Health Group Therapy (PT 27), EPSDT Therapeutic Behavioral Services (PT 51), 1915(i) Intensive Behavioral Health Services (PT 89 and PT HG), and the individual practitioner types most programs employ: Certified Professional Counselor covering LCPC, LCMFT, LCADC, and LC-PAT (PT CC), Social Worker requiring LCSW-C (PT 94), Psychologist (PT 15), and Nurse Psychotherapist, APRN-PMH (PT 24).

The December 31 cliff

This is the part worth reading twice, because it is where the money is.

MDH will grant backdated enrollment effective dates, but only on conditions (PT 94-26, June 18, 2026). A newly enrolling provider who submits a complete and processable application in MPRIME on or before December 31, 2026 gets an effective date set to the later of:

1. the start of that provider's application hold, meaning July 1 for high and moderate risk types or August 1 for limited risk types, or
2. the provider's license issuance date.

Miss it, or submit something incomplete, and there is no backdate. Your effective date gets set by the ordinary rules, and every service delivered between the hold and enrollment becomes unbillable. MDH is explicit that you may not bill the participant for it either.

Three details inside that rule that catch people out:

"Complete and processable" is doing real work in that sentence. An application returned for corrections is not a submitted application. If you file on December 22 and it bounces, you have nine days to fix it. File early enough to absorb one rejection.

Timely filing does not move. The 12 month claim submission window still runs from the date of service, not from the date your backdate is granted. A service delivered July 2 has to be claimed by July 2027 regardless. Once the backdate lands, submit the held claims immediately rather than working through them at a comfortable pace.

Backdates are not guaranteed. MDH says plainly that providers who render services without enrolling do so at risk.

Two more deadlines in the same transmittal

Both of these are easy to miss because they read like administrative housekeeping, and both end in an automatic status change.

December 1, 2026: suspended providers terminate. MDH deferred termination for every provider whose one year suspension would have ended between July 1 and November 30, 2026, so they stay suspended rather than terminating during the hold. Their termination date is now December 1. If one of your rendering providers is sitting in suspended status, the update that resolves it has to be filed in MPRIME between go live and December 1. After that the account terminates automatically.

November 15, 2026: out of state licenses. Suspension is deferred for out of state individually licensed providers whose license expires between August 1 and November 15, 2026. Updated license information has to go into MPRIME by November 15 or the account suspends automatically. Programs near the DC and Pennsylvania and Delaware lines, and any telehealth roster with out of state clinicians, should pull that list now.

Your MPRIME login is not your ePREP login

The dates are now set. MPRIME launches October 13, 2026. Before that, on October 1, 2026, providers lose access to the documents stored in ePREP (MDH transmittal of September 16, 2026, relayed in Carelon's provider alert of the same day). If there is anything in ePREP you might need later, an old application, an approval letter, a revalidation confirmation, download it in September. There is a twelve day gap where neither portal is open to you.

Existing enrollment records get preloaded into MPRIME. User profiles do not.

Every user has to create a new MPRIME account and then re associate with the existing provider records to get access and administrative rights back. That means the week of October 13 is not the week to discover that the only person who held admin rights in ePREP left the practice in March.

One more prerequisite that is new with MPRIME: you need an active SDAT identification number in good standing, matched to your organizational structure, or the system will not accept an application. Individual billing providers should confirm theirs begins with L.

Decide now who your MPRIME administrator is, who the backup is, and make sure both are people who still work there. MDH has posted training registration, and prerecorded sessions are going to the MPRIME webpage before launch. The sessions cover registration, new applications, update applications, and revalidation (PT 04-27, July 12, 2026).

Getting authorizations while you wait

Authorization requirements did not pause just because enrollment did.

MDH published a temporary process on August 21, 2026 for behavioral health providers who are unenrolled solely because of the hold. You register your NPI with Carelon through a form on the MPRIME webpage, submitting every license, certification, and DEA registration that applies to the provider type and the services you intend to enroll for. That makes you eligible to request courtesy authorizations for services delivered before enrollment.

Three limits on it:

• Only groups, facilities, and individual billers or sole proprietors who submit claims use this form. Rendering only providers, and existing groups adding rendering providers, do not.
• A courtesy authorization is not a guarantee of payment. If enrollment requirements are not met, it does not save the claim.
• It does not apply to providers blocked by the regional moratorium rather than the hold. That is a different policy with a different remedy, and PT 88-26 governs it.

And the operational instruction that follows from all of it: hold the claims. Do not submit and let them deny. Park them until the Medicaid ID issues and the backdate is granted, then release them.

What to do this week

1. Pull a list of every clinician and every program NPI that has rendered a Medicaid service since July 1 without an approved Medicaid enrollment. If you cannot produce that list in an afternoon, that is the finding.
2. For each one, record the license issuance date. It is half of the backdate formula and it is the half you control the documentation for.
3. Confirm the courtesy authorization registration is on file with Carelon for every entity that needs one, and that authorizations exist for the services already delivered.
4. Name your MPRIME administrator and backup. Verify both are current employees, and check your SDAT number is active.
5. Download anything you may need from ePREP before October 1. Access to ePREP documents ends that day; MPRIME opens October 13.
6. Register for MPRIME training now rather than in October.
7. Run two reports: rendering providers in suspended status (December 1), and out of state licenses expiring between August 1 and November 15 (November 15).
8. Put December 1 on the calendar as your internal MPRIME filing deadline, not December 31. The month of slack is the point.

The documentation angle

The backdate is a documentation exercise wearing a billing costume.

When you file in MPRIME, the claim to a backdated effective date rests on records you either kept or did not: the provider's license issuance date, the date the hold closed their tier, the authorization numbers obtained under the courtesy process, and a clean, dated service log for everything delivered in between. Practices that tracked unenrolled rendering providers as a distinct status, with claims held in a queue rather than submitted and denied, will release that revenue in a batch in January. Practices that let those services blend into the general unbilled pile will spend the winter reconstructing them from calendars and memory, against a 12 month filing clock that started in July.

The other thing worth writing down now is who is watching which deadline. Five dates (October 1, October 13, November 15, December 1, December 31) spread across credentialing, billing, and clinical leadership is exactly the shape of problem where everyone assumes someone else has it.

Also this week: the COMAR 10.63 comment period closed September 21, 2026. BHA now reviews the written record; the next public step is a notice of final action in the Maryland Register. Our read of the proposed subtitle is here, and we will update it when the final text publishes.