Unified Financial Automation Architecture in Pharmacy Benefit Management: Integrating Event-Driven Microservices, AI-Driven Decisioning, and Regulatory Compliance for Enterprise-Scale Healthcare Operations

Abstract

Pharmacy benefit management platforms in the United States administer a substantial volume of prescription drug claims each year, yet the financial infrastructure underlying rebate processing, remittance settlement, and compliance verification continues to operate on fragmented, batch-oriented architectures that are structurally misaligned with the demands of modern, real-time healthcare finance. A unified financial automation architecture is proposed and evaluated that integrates event-driven microservices, AI-driven anomaly detection, and multi-dimensional regulatory compliance into a cohesive enterprise-scale platform for PBM financial operations. The architecture is organized across three functional layers: an ingestion and stream alignment layer that normalizes NCPDP D.0 and EDI 837 claim events through a distributed event broker; a distributed adjudication core that enforces CQRS separation of write and read paths with event sourcing for immutable audit trail construction; and a settlement and cryptographic audit layer that applies transactional guarantees, outbox-pattern delivery, and tamper-evident signing to every financial state transition. An Isolation Forest anomaly detection model operates continuously within the adjudication pipeline, supporting a three-tier triage classification for financial discrepancies. Design science research methodology applied to a multi-tenant PBM platform validation environment yields results indicating measurable improvement in settlement velocity, reduction in reconciliation lag, and improved anomaly detection accuracy across rebate billing, remittance processing, and claim adjudication workloads. The architecture addresses HIPAA financial data governance requirements, Medicaid Drug Rebate Program obligations, SOX financial control mandates, and state PBM transparency statutes within a unified compliance enforcement model.