FHIR Versions

Health Gorilla APIs are built on the HL7® FHIR® (Fast Healthcare Interoperability Resources) standard to enable structured, interoperable clinical data exchange. FHIR provides a RESTful interface for accessing patient records, documents, lab results, and other clinical data.

Supported Versions

Health Gorilla supports the following FHIR versions:

Version	Use Case	Status
R4	Default for all new implementations	Recommended
STU3	Legacy support for `$p360-retrieve` and other workflows	Maintained for compatibility

Each FHIR version has its own URL namespace and resource definitions. You must not mix FHIR versions within a single implementation.

Resource Structure and Formatting

FHIR resources are returned in JSON format and follow the HL7 specification for their respective version. Each resource contains:

resourceType identifies the FHIR resource (such as Patient, Observation, or Encounter)
id is the logical identifier assigned by the system
meta includes version ID, timestamps, and metadata tags
identifier contains one or more external identifiers (such as MRNs, NPIs, or SSNs)
Clinical and contextual elements such as status, code, value, subject, and effectiveDateTime are populated based on resource type

Version Guidance

Health Gorilla recommends FHIR R4 for all new implementations. FHIR STU3 is maintained only for legacy workflows such as $p360-retrieve and specific bulk export operations.

Area	R4	STU3
Primary use	All new implementations	Legacy only
Async job handling	Optional	Required for `$everything` and `$export-ccda`
SMART on FHIR	Supported	Not supported
Resource coverage	Aligned with USCDI	Limited

Coding and Interoperability Standards

FHIR resources returned by Health Gorilla include codes from standard terminologies.

LOINC®: Laboratory and clinical observations
SNOMED CT®: Problems, diagnoses, and findings
RxNorm: Medications and drug references
ICD-10-CM: Billing and encounter diagnoses
HL7 v3 Act Codes: Document types, status codes applications with SMART on FHIR protocols