Healthcare networks running multiple EHRs, clinical systems, and payer platforms rely on seven FHIR integration patterns that show up repeatedly in successful deployments.
1. FHIR API gateway. Central gateway routes to backend systems, enforces auth, and normalizes response shapes. Uses FHIR REST spec as canonical contract.
**2. Bulk Data IG for cross-system analytics.** Each system exports; central warehouse ingests. Warehouse becomes the analytics-of-record.
3. Terminology harmonization via ConceptMap. Different systems use different code systems; ConceptMaps translate at the API gateway or ingestion layer.
4. MPI federation. Multiple systems each maintain local Patient records; central MPI federates identities via Patient.link.
5. Cross-system Subscription. Subscription delivers events across system boundaries; subscribers register at the gateway.
6. Shared terminology server. Centralized terminology server serves all systems; consistent bindings across the network.
7. Cross-system audit trail. AuditEvent resource captures cross-system data access; centralized for compliance reporting.
Common integration failures
| Failure | Root cause |
|---|---|
| Duplicate patients across systems | No MPI federation |
| Analytics discrepancy | Terminology drift |
| Access audit gaps | Fragmented AuditEvent |
| Subscription delivery failures | Per-system reliability |
| Auth boundary confusion | Multiple auth servers |
Governance investment
Cross-system integration requires cross-system governance. A single team owns the seven patterns above; per-system teams follow. Without central ownership, each system optimizes locally and network coherence degrades.
Seven-pattern integration is a design discipline more than a technology choice. Get the patterns aligned across teams before integration work begins.
