FHIR, pronounced "fire," stands for Fast Healthcare Interoperability Resources. It is the dominant standard for exchanging electronic health information between different systems, developed and maintained by HL7 International. FHIR defines a set of data models called resources, each representing a discrete clinical or administrative concept: a Patient, an Observation, a Medication, a Condition, an Encounter, and so on. Systems that implement FHIR can share these resources over standard web APIs, making it significantly easier to connect health IT platforms that were previously siloed.
The US federal government has mandated FHIR adoption for most healthcare organizations through the 21st Century Cures Act and related CMS rules. Health systems, payers, and health IT vendors that accept Medicare and Medicaid payments must provide FHIR-based APIs that allow patients and authorized third parties to access their health data. This regulatory push has made FHIR proficiency a requirement rather than an option for healthcare technology teams.
For technology companies building in healthcare, FHIR is both an integration target and an integration mechanism. Connecting to an electronic health record system such as Epic or Cerner typically means implementing FHIR APIs. Building a patient-facing application that needs to pull data from a health system requires understanding FHIR resource types and the system's FHIR server implementation. Salesforce Health Cloud's interoperability features are built on FHIR.
FHIR proficiency requires both technical understanding of the standard and domain knowledge of healthcare data models. The same FHIR resource can be populated differently by different health systems, and the gap between what FHIR defines and what a specific EHR's FHIR implementation actually supports is often significant in practice.