About FHIR
The standard your EHR finally talks.
FHIR (Fast Healthcare Interoperability Resources, pronounced "fire") is HL7's modern standard for exchanging healthcare data over REST. R4 has been the widely adopted version since October 2019, with R5 landing in March 2023 for newer implementations. Where the older HL7 v2 messaging shipped pipe-delimited segments over a socket, FHIR ships JSON or XML resources over HTTPS. That is the reason it stuck.
Once you start reading a FHIR endpoint, the same handful of resources show up in nearly every implementation: Patient, Practitioner, Organization, Encounter, Observation, Condition, MedicationRequest, Procedure, AllergyIntolerance and DiagnosticReport. Resources reference each other by id and most servers expose them under predictable URLs like /Patient/123 and /Observation?patient=123, with a /metadata endpoint describing what that server supports. Every server picks its own profile.
The point of pulling FHIR into a warehouse is to put clinical data next to the things it never sat next to before: the claim that was billed against the encounter, the invoice that was paid, the rota for the shift the encounter happened on, the prior-auth turnaround for the medication that was requested. The clinical depth stays in the EHR. The cross-cuts you couldn't run before become queryable.