This page is part of the FHIR Specification v4.1.0: R4B Ballot. About the R4B version of FHIR. The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R4B R4 R3 R2

• Using Codes
• Code Systems
• Value Sets
• Concept Maps
• Identifier Systems

4.3.6 Using NDF-RT (the National Drug File - Reference Terminology) with FHIR

Vocabulary Work Group

Maturity Level: 2

Standards Status: Trial Use

4.3.6.1 Summary

Source	the National Drug File - Reference Terminology - prepared by Veterans Health Administration , and distributed as part of UMLS by the NLM (direct link )
System	The URI to identify NDF-RT is not resolved. As a temporary arrangement, the URL "http://hl7.org/fhir/ndfrt" is to be used
Version	A version is not needed. (Use the date of the UMLS release for the version of NDF-RT if a version is desired.)
Code	The NUI is used for the code value for an NDF-RT concept
Display	??
Inactive	Todo: Describe how it is determined which concepts are inactive
Subsumption	Subsumption testing is based in the Is-a relationship defined by NDFRT
Filter Properties	None are described yet

This URL is temporary while the NDF-RT and FHIR teams discuss the long term arrangements. Further documentation can be found in evs .

4.3.6.2 Version Issues

NDF-RT is released as part of UMLS. Therefore, each successive release has the date of the UMLS release as its version.

4.3.6.3 Copyright/License Issues

NDF-RT has no copyright acknowledgement required. However, users must adhere to the UMLS license.

4.3.6.4 NDF-RT Filter Properties

This section documents the property filters that can be used with the SNOMED CT code system in value set composition statements.

4.3.6.4.1 By Subsumption

Others yet to be done.

4.3.6.5 Implicit Value Sets

Yet to be done.