US Core Requires at Least One Identifier on Patient
The US Core Patient profile mandates Patient.identifier. A Patient with a name and gender but no identifier is valid base FHIR but fails US Core conformance.
FHIR · Error
The error
US Core requires at least one Identifier on PatientWhy it happens
Generating demographics without a medical record number, or converting from a source that did not carry an identifier system and value.
How to fix it
Add at least one identifier with a real system URI and a value. The system should be an absolute URI identifying the assigning authority (for example a hospital MRN namespace), not a bare label.
Example
The snippet below triggers the error:
{
"resourceType": "Patient",
"name": [{ "family": "Doe", "given": ["John"] }],
"gender": "male"
}The corrected version:
{
"resourceType": "Patient",
"identifier": [{ "system": "http://hospital.example.org/mrn", "value": "MRN12345" }],
"name": [{ "family": "Doe", "given": ["John"] }],
"gender": "male"
}Frequently asked questions
Does the identifier need a system?
For meaningful conformance, yes. An identifier carries a system (the namespace URI of the assigning authority) and a value. A bare value with no system is ambiguous and weakens interoperability.