OrganizationAffiliation — Inter-organization affiliation
One Organization is a member, supplier, or partner of another. OrganizationAffiliation carries the relationship. Pivot for Provider Directory.
Purpose
OrganizationAffiliation models facility-to-facility links: clinic affiliated to a group, clinic partnered with an insurer network, hospital approved by an insurer, laboratory subcontractor. Used by directories (US Healthcare Directory, ANS extended RPPS) to answer 'which providers cover this area?'.
Key fields
| Field | Type | Cardinality | Role |
|---|---|---|---|
identifier | Identifier[] | 0..* | External identifiers. |
active | boolean | 0..1 | Affiliation active. |
period | Period | 0..1 | Validity period. |
organization | Reference(Organization) | 0..1 | Hosting organisation. |
participatingOrganization | Reference(Organization) | 0..1 | Participating organisation. |
network | Reference(Organization)[] | 0..* | Healthcare networks. |
code | CodeableConcept[] | 0..* | Role. |
specialty | CodeableConcept[] | 0..* | Concerned specialties. |
location | Reference(Location)[] | 0..* | Concerned locations. |
endpoint | Reference(Endpoint)[] | 0..* | Affiliation-specific endpoints. |
JSON example
Clinic → hospital-network affiliation:
{
"resourceType": "OrganizationAffiliation",
"id": "example",
"identifier": [{ "system": "http://example.org/affiliations", "value": "AFF-2026-001" }],
"active": true,
"period": { "start": "2026-01-01" },
"organization": { "reference": "Organization/clinic-affiliated" },
"participatingOrganization": { "reference": "Organization/hospital-network" },
"network": [{ "reference": "Organization/insurer-network" }],
"code": [{
"coding": [{
"system": "http://terminology.hl7.org/CodeSystem/organization-role",
"code": "member",
"display": "Member"
}]
}],
"specialty": [{
"coding": [{ "system": "http://snomed.info/sct", "code": "394814009", "display": "General medicine" }]
}]
}Common pitfalls
- organization = participatingOrganization: self-reference forbidden, check on write.
- period missing: cannot tell if the affiliation is still valid.
- Confusion with PractitionerRole: OrganizationAffiliation = Org↔Org, PractitionerRole = Practitioner↔Org.
Related resources
- Organization — The linked organisations.
- PractitionerRole — Practitioner-organisation affiliation.
- HealthcareService — Provided services.
- Endpoint — Technical endpoints.