FHIR R4 Core Resources
FHIR organizes healthcare data into resources — discrete, individually addressable data objects with a defined structure. FHIR R4 defines over 150 resource types, organized into categories.
Key Resources by Category
Foundation Resources
| Resource | Purpose |
|---|---|
| Bundle | Container for a collection of resources (searchset, transaction, document, message) |
| CapabilityStatement | Declares what a FHIR server can do (resources supported, search parameters, operations) |
| OperationOutcome | Error and informational messages returned from operations |
| OperationDefinition | Defines a custom operation (e.g., $export, $member-match) |
Individual Resources
| Resource | Purpose |
|---|---|
| Patient | Demographics and administrative information about the individual receiving care |
| Practitioner | Healthcare professional demographics (physician, nurse, therapist) |
| PractitionerRole | The role a practitioner plays at an organization (specialties, locations) |
| RelatedPerson | A person related to the patient (emergency contact, caregiver) |
| Organization | Hospital, clinic, insurance company, or other healthcare organization |
| Location | Physical place where services are provided |
Clinical Resources
| Resource | Purpose |
|---|---|
| Condition | Diagnosis or health concern (ICD-10 coded) |
| Procedure | An action performed on a patient (CPT/HCPCS coded) |
| Observation | Measurement or assertion (vital signs, lab results, social history) |
| AllergyIntolerance | Allergies and intolerances |
| Encounter | An interaction between patient and provider (visit, admission) |
| DiagnosticReport | Results of a diagnostic study (lab panel, imaging report) |
| MedicationRequest | A prescription or medication order |
| Immunization | Vaccination record |
| CarePlan | Planned healthcare activities and goals |
Financial Resources
| Resource | Purpose |
|---|---|
| Claim | Request for payment or prior authorization |
| ClaimResponse | Adjudication result for a Claim |
| ExplanationOfBenefit | Detailed payment and adjudication information (EOB/ERA equivalent) |
| Coverage | Insurance coverage details for a patient |
| CoverageEligibilityRequest | Eligibility inquiry (FHIR equivalent of EDI 270) |
| CoverageEligibilityResponse | Eligibility response (FHIR equivalent of EDI 271) |
Workflow Resources
| Resource | Purpose |
|---|---|
| Task | A unit of work to be performed |
| ServiceRequest | A request for a service (referral, lab order, imaging order) |
RESTful Interactions
FHIR servers support standard REST operations:
| Operation | HTTP Method | Example |
|---|---|---|
| Read | GET | GET /Patient/123 |
| Search | GET | GET /Patient?name=Smith&birthdate=1990-01-01 |
| Create | POST | POST /Patient with body |
| Update | PUT | PUT /Patient/123 with body |
| Delete | DELETE | DELETE /Patient/123 |
| History | GET | GET /Patient/123/_history |
| Transaction | POST | POST / with Bundle of type transaction |
References Between Resources
Resources reference each other using the Reference data type:
{
"resourceType": "Condition",
"subject": {
"reference": "Patient/123",
"display": "John Smith"
},
"encounter": {
"reference": "Encounter/456"
}
}
