HL7 Terminology (THO)
5.1.0 - Publication International flag

This page is part of the HL7 Terminology (v5.1.0: 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

Using MED-RT with HL7 Standards

This page describes how to use MDC with HL7 Standards.

The Medication Reference Terminology (MED-RT) replaced the National Drug File Reference Terminology (NDF-RT) as of UMLS v17AB. NDF-RT is no longer being maintained.

Using MED-RT with FHIR R5


SourceMedication Reference Terminology - prepared by Veterans Health Administration, and distributed as part of UMLS by the NLM (direct link)
VersionUse the date of the UMLS release as the version of MED-RT (if a version is desired).
CodeThe NUI is used for the code value for an MED-RT concept
DisplayThe concept name should be used as the display.
InactiveThere are no codes that are inactive.
SubsumptionSubsumption testing is based on the Is-a relationship defined by MED-RT
Filter PropertiesNone are described yet.

Usage Notes

The MED-RT code system includes relationships between MED-RT concepts and concepts in external code systems, as well as relationships between concepts only in the external code systems. The external code systems that MED-RT references include RxNorm, MeSH, and SNOMED CT US Edition.

The representation of the contents of MED-RT in a FHIR CodeSystem resource may contain all concepts defined as existing solely in MED-RT, and relationships between concepts defined within MED-RT, and between MED-RT concepts and a concept in an external code system. In addition, ConceptMap resource(s) will be needed in order to represent the relationships in MED-RT that exist between external code systems.

Currently all references to external code systems in MED-RT are to a specific version of the external code system.

For more information, see the NCI MED-RT page.

Version Issues

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

Copyright/License Issues

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

MED-RT Filter Properties

This section documents the property filters that can be used with the MED-RT code system in value set composition statements (ValueSet.compose).

By Subsumption
DescriptionSelect a set of concepts based on subsumption testing
Property Nameconcept
Operations Allowedis-a
Values AllowedNUI
CommentsIncludes all concepts that have a transitive is-a relationship with the concept Id provided in the value as an NUI (including the concept itself)

MED-RT Implicit Value Sets

No need for implicit value sets identified yet.