HL7 Terminology (THO)
4.0.0 - Publication International flag

This page is part of the HL7 Terminology (v4.0.0: Release) based on FHIR R4. The current version which supercedes this version is 5.2.0. For a full list of available versions, see the Directory of published versions

FHIR Code Systems

This page contains the FHIR code systems that are available for browsing through the HL7 Terminology pages. The docuemnttion here refers specifically to the use of this content in FHIR artifacts.

The code system names and their URIs may be used in the system element of the Coding data type. If a URI is defined here, it SHALL be used in preference to any other identifying mechanisms. If a code system is not listed here, the correct URI may be determined by working through the following list, in order:

  • the HL7 OID Registry
  • the documentation associated with the code system
  • consulting the owner of the code system
  • asking on the HL7 vocabulary mailing list

See also the list of known identifier systems that can be used in the system element of the Identifier data type. Additional identifier systems may be registered on the HL7 FHIR registry at http://hl7.org/fhir/registry.

Important Notes:

  • This list of names is incomplete and subject to change. Some values may be dropped, and others will likely be added in the coming months as HL7 institutes formal processes around URIs in vocabulary
  • Note that some of the URNs in this list follow the URN specification in RFC 5141 for referring to standards published by ISO, such as urn:iso:std:iso:11073:10101. Where ISO standards define codes with meanings, and there is no entry in the list above, and they are not registered in the HL7 OID registry, the default URN for the code system is that defined by the RFC 5141.
  • For several of the code systems in this list, multiple systems are given. This means that the variants identified are different code systems, not just variants of the same code system
  • Any URL in http://example.org is reserved for testing and documentation purposes.

Note that the code systems are available as FHIR resources - see the Downloads Page (as part of the FHIR definitions) (excluding the External code systems.

UMLS Note: The UMLS includes many code systems that do not have an entry in the table below, or in the HL7 OID registry, or on http://registry.fhir.org. Until these code systems are registered, implementers may use the pattern http://www.nlm.nih.gov/research/umls/[SAB], where [SAB] is the lowercase of abbreviation of the code system as provided by UMLS. e.g. The system for "Multum MediSource Lexicon" would then be http://www.nlm.nih.gov/research/umls/mmsl. Implementers choosing to use this pattern should be aware that very often, when the code system is registered, it will use a different system.

It has been noted that this UMLS statement above is not completely correct, and the UTG team is awaiting the correction. Stay tuned.

Don't see what you're looking for here? See Registering Code Systems for further advice.