US Core Implementation Guide
4.1.0 - CI Build

US Core Implementation Guide, published by HL7 International - US Realm Steering Committee. This is not an authorized publication; it is the continuous build for version 4.1.0). This version is based on the current content of and changes regularly. See the Directory of published versions


This page lists all the ValueSets, CodeSystems, and ConceptMaps defined as part of the US Core implementation Guide. For more information on using codes in Us Core, see the FHIR Terminology section in the FHIR specification and Must Support - Coded Elements in this guide.

Value Sets

These value sets have been defined for this implementation guide.

Code Systems

See the FHIR terminology section for a complete discussion on code systems and a list of codes system names used in FHIR. Most code systems used in this guide are defined in the base FHIR specification. The following code systems are unique to this guide and not listed in the base FHIR specification. If a URI is listed here, it SHALL be used in the US Core profiles to identify the code system in preference to any other code system URI.

Code systems published in this IG - Includes US Core defined code systems and externally defined code systems

* In the future, the Race & Ethnicity - CDC code system and value sets will migrate from US Core to HL7 Terminology.

Externally Published code systems

URI Source Comment OID (for non-FHIR systems) CMS Healthcare Common Procedure Coding System (HCPCS) level II alphanumeric codes 2.16.840.1.113883.6.285 CMS International Classification of Diseases, 10th Revision, Procedure Coding System (ICD-10-PCS) - See ICD-10 PCS Codes for online access to codes for general information purposes. 2.16.840.1.113883.6.4 ADA Code on Dental Procedures and Nomenclature 2.16.840.1.113883.6.13 USPS United States Postal Service Two–Letter State and Possession Abbreviations 2.16.840.1.113883.6.92

Using Value Set Authority Center (VSAC)

This guide links terminology directly to the FHIR® Terminology Service for VSAC Resources (Value Set Authority Center (VSAC) - NIH) where applicable using a RESTful API service for accessing the VSAC value sets and supported code systems.

  • It is a requirement of VSAC to log in using your own UMLS API Key to view the value sets. VSAC UMLS Licensing information. (See the screen shots below)
  • The value sets in VSAC are specified using a VSAC value set OID.
  • The retrieval of a value set using the FHIR API structure using just the OID provided will only retrieve the value set definition, when available, and to obtain the expansion, the expansion operation is used.

For example, the US Core Smoking Status Observation Profile valueCodeableConcept element has a preferred binding to the Smoking Status value set in VSAC using this link The screenshot below illustrates that by clicking on the link:

Figure 1: VSAC link

The reader is redirected to the VSAC login page to enter an API Key:

Figure 2: VSAC API-Key Login

After successfully entered the API Key the value set can be inspected, downloaded, etc:

Figure 3: VSAC Smoking Status ValueSet

Note that only one login is required per session.