MedicaidAdministrativeHigh impact
Update on billing codes: EOB 1504/Edit 1946
Mississippi Medicaid (DOM)·MS·Claims & Billing
We identified it
Jun 21, 2026
Summary
Mississippi Medicaid EOB Code 1504 will now DENY claims (previously processed differently) when the rendering provider NPI and taxonomy code cannot be uniquely matched in their system. Claims must include both the correct NPI and matching taxonomy code in specific fields to avoid denials.
Action Required
Immediately: Billing team must verify all rendering provider NPIs have matching taxonomy codes on file with Gainwell Technologies using the Taxonomy Lookup Tool on the Division of Medicaid website. For paper claims (CMS 1500), ensure FL 24J includes both Rendering ID and corresponding Taxonomy Code with ID Qualifier ZZ. For EDI submissions, follow EDI Companion Guide requirements. Claims missing or having mismatched NPI/taxonomy combinations will now be DENIED instead of processed.