ConceptMap Operations
ConceptMap resources define mappings between codes in different code systems -- essential for data integration across systems that use different terminologies.
The pre-built terminology service currently focuses on ValueSet and CodeSystem operations. ConceptMap operations ($translate, $closure) are FHIR-standard reference/examples for future implementation — not currently supported by the terminology service.
ConceptMap in FHIR
A ConceptMap defines relationships between codes in a source code system and codes in a target code system. Common use cases include:
| Source | Target | Use Case |
|---|---|---|
| ICD-9-CM | ICD-10-CM | Legacy system migration |
| HL7v2 tables | FHIR code systems | HL7v2 to FHIR transformation |
| Local codes | SNOMED CT | Standardization |
| SNOMED CT | ICD-10 | Billing and reporting |
$translate
The $translate operation translates a code from one system to another using a ConceptMap.
FHIR-standard reference/example for future implementation — not currently supported by the terminology service.
Request
GET /fhir/r4/ConceptMap/$translate?url=http://example.org/ConceptMap/icd9-to-icd10&system=http://hl7.org/fhir/sid/icd-9-cm&code=250.00&targetsystem=http://hl7.org/fhir/sid/icd-10-cm
Response
{
"resourceType": "Parameters",
"parameter": [
{"name": "result", "valueBoolean": true},
{
"name": "match",
"part": [
{"name": "equivalence", "valueCode": "equivalent"},
{
"name": "concept",
"valueCoding": {
"system": "http://hl7.org/fhir/sid/icd-10-cm",
"code": "E11.9",
"display": "Type 2 diabetes mellitus without complications"
}
}
]
}
]
}
Match Equivalence Types
| Equivalence | Meaning |
|---|---|
equivalent | Exact semantic match |
wider | Target is broader in meaning |
narrower | Target is narrower in meaning |
inexact | Approximate match |
unmatched | No match found |
Creating ConceptMaps
You can define custom ConceptMap resources for your mappings:
{
"resourceType": "ConceptMap",
"url": "http://example.org/ConceptMap/local-to-loinc",
"status": "active",
"sourceUri": "http://example.org/CodeSystem/local-lab-codes",
"targetUri": "http://loinc.org",
"group": [
{
"source": "http://example.org/CodeSystem/local-lab-codes",
"target": "http://loinc.org",
"element": [
{
"code": "GLU",
"display": "Glucose",
"target": [
{
"code": "2345-7",
"display": "Glucose [Mass/volume] in Serum or Plasma",
"equivalence": "equivalent"
}
]
}
]
}
]
}