HL7 Terminology (THO)
5.3.0 - Publication International flag

This page is part of the HL7 Terminology (v5.3.0: Release) based on FHIR R4. This is the current published version in its permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions

External Code Systems

The table below Using external code systems with HL7 Standards. Please note that the Code System Metadata Record associated with each external code system in the table is the authoritative source of information regarding the correct use of external terminologies with FHIR and other HL7 standards including HL7 endorsed system URI and OID identifiers.

Name Owner / Maintainer URI OID Metadata Record Use with HL7 Standards
SNOMED CT International Edition IHTSDO / SNOMED International http://snomed.info/sct 2.16.840.1.113883.6.96 SNOMED CT International Edition See Using SNOMED CT with HL7 Standards
RxNorm National Library of Medicine (NLM) http://www.nlm.nih.gov/research/umls/rxnorm 2.16.840.1.113883.6.88 RxNorm See Using RxNorm with HL7 Standards
Logical Observation Identifiers, Names and Codes (LOINC) Regenstrief Institute, Inc http://loinc.org 2.16.840.1.113883.6.1 LOINC See Using LOINC with HL7 Standards
pan-Canadian LOINC Observation Code Database (pCLOCD) Canada Health Infoway https://fhir.infoway-inforoute.ca/CodeSystem/pCLOCD 2.16.840.1.113883.2.20.5.1 pCLOCD See Using pCLOCD with HL7 Standards
Unified Code for Units of Measure (UCUM) Regenstrief Institute, Inc http://unitsofmeasure.org 2.16.840.1.113883.6.8 UCUM See Using UCUM with HL7 Standards
Current Procedural Terminology (CPT) American Medical Association (AMA) http://www.ama-assn.org/go/cpt 2.16.840.1.113883.6.12 CPT See Using CPT with HL7 Standards
Medication Reference Terminology (MED-RT) National Library of Medicine (NLM) http://va.gov/terminology/medrt 2.16.840.1.113883.6.345 MED-RT See Using MED-RT with HL7 Standards
National Drug File Reference Terminology (NDF-RT) U.S. Department of Veterans Affairs, Veterans Health Administration http://hl7.org/fhir/ndfrt 2.16.840.1.113883.6.209 NDF-RT See Using NDF-RT with HL7 Standards
Unique Ingredient Identifier (UNII) U.S. Food and Drug Administration (FDA) http://fdasis.nlm.nih.gov 2.16.840.1.113883.4.9 UNII See Using UNII with HL7 Standards
National Drug Code (NDC) U.S. Food and Drug Administration (FDA) http://hl7.org/fhir/sid/ndc 2.16.840.1.113883.6.69 NDC See Using NDC with HL7 Standards
Vaccine Administered Code Set (CVX) Centers for Disease Control and Prevention (CDC) http://hl7.org/fhir/sid/cvx 2.16.840.1.113883.12.292 CVX See Using CVX with HL7 Standards
ISO 3166 Country Codes International Organization for Standardization (ISO)
  • Part 1, Country Codes (2-letter and 3-letter, and numerical codes): urn:iso:std:iso:3166
  • Part 2, Subdivision (State/Province) Codes: urn:iso:std:iso:3166:-2
  • Part 3, Historical Country Names: urn:iso:std:iso:3166:-3
  • Part 1, Country Codes (2-letter and 3-letter, and numerical codes): 1.0.3166.1
  • Part 2, Subdivision (State/Province) Codes: 1.0.3166.2
  • Part 3, Historical Country Names: TBD
 See Using ISO 3166 with HL7 Standards
International Classification of Diseases (ICD) World Health Organization (WHO) Check metadata record Check metadata record See Using ICD with HL7 Standards
Medical Device Communications (MDC) International Organization for Standardization (ISO) urn:iso:std:iso:11073:10101 2.16.840.1.113883.6.24 MDC See Using MDC with HL7 Standards