HL7 v2 still wins for hospital interface engines today; FHIR R4 wins for modern ambulatory EHRs and digital-health platforms. The right first-build depends on which EMRs your near-term customers run.
When HL7 v2 still wins for hospital integrations, when FHIR R4 is the better first build for ambulatory and digital-health customers, and how LabFlow ships both.
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