US Core Implementation Guide
7.0.0 - STU7 United States of America flag

US Core Implementation Guide, published by HL7 International / Cross-Group Projects. This guide is not an authorized publication; it is the continuous build for version 7.0.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of and changes regularly. See the Directory of published versions

ValueSet: Language codes with language and optionally a region modifier

Official URL: Version: 7.0.0
Standards status: Trial-use Maturity Level: 3 Computable Name: LanguageCodesWithLanguageAndOptionallyARegionModifier
Other Identifiers: OID:2.16.840.1.113883.4.642.

Copyright/Legal: ISO Maintains the copyright on the country codes and controls it’s use carefully. For further details, see the ISO 3166 Home Page

This value set includes codes from BCP-47. This value set matches the ONC 2015 Edition LanguageCommunication data element value set within C-CDA to use a 2 character language code if one exists, and a 3 character code if a 2 character code does not exist. It points back to RFC 5646, however only the language codes are required, all other elements are optional.


The publication tooling cannot expand the language value set because they are based on a grammar. To aid in the reader’s understanding, sample codes are shown below:

Examples of 2-character codes for common languages

ISO 639-1 Code English name of Language
en English
es Spanish
zh Chinese
fr French
tl Tagalog
vi Vietnamese

Examples of 3-character code for languages where a 2-character code does not exist

ISO 639-2 Code English name of Language
yue Cantonese
chn Chinook jargon
cho Choctaw
chp Chipewyan
chr Cherokee

For a more complete list of both 2 and 3-letter examples, see

Logical Definition (CLD)

  • Include codes from urn:ietf:bcp:47 where ext-lang doesn't exist, script doesn't exist, variant doesn't exist, extension doesn't exist and private-use doesn't exist



This value set cannot be expanded because of the way it is defined - it has an infinite number of members

Explanation of the columns that may appear on this page:

Level A few code lists that FHIR defines are hierarchical - each code is assigned a level. In this scheme, some codes are under other codes, and imply that the code they are under also applies
System The source of the definition of the code (when the value set draws in codes defined elsewhere)
Code The code (used as the code in the resource instance)
Display The display (used in the display element of a Coding). If there is no display, implementers should not simply display the code, but map the concept into their application
Definition An explanation of the meaning of the concept
Comments Additional notes about how to use the code