minimal Common Oncology Data Elements (mCODE) Implementation Guide, published by HL7 International / Clinical Interoperability Council. This guide is not an authorized publication; it is the continuous build for version 4.0.0-ballot built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/fhir-mCODE-ig/ and changes regularly. See the Directory of published versions

Terminology

This implementation guide draws on a number of formal terminologies (code systems). Several guiding principles were applied in selecting terminologies for mCODE:

1. Fit for purpose
2. Conformance with US Core and FHIR
3. Commonly used in real world practice

The following table presents the external code systems (and naming conventions) adopted in mCODE, and their primary purpose:

Code System	Domain	FHIR IG Publishing support?	HL7 Canonical
CPT	Procedure codes	No	http://www.ama-assn.org/go/cpt
HGNC	Gene identification	No	http://www.genenames.org
HGVS	Sequence variant nomenclature	Yes	http://varnomen.hgvs.org
HTA	Various HL7 V2 and FHIR-specific codes	Yes	http://terminology.hl7.org
ICD-O-3	Cancer morphology and topology codes	No	http://terminology.hl7.org/CodeSystem/icd-o
ICD-10-CM	Diagnosis codes	Yes	http://hl7.org/fhir/sid/icd-10-cm
ICD-10-PCS	Procedure codes	No	http://www.cms.gov/Medicare/Coding/ICD10
LOINC	Observation and laboratory codes, answer codes	Yes	http://loinc.org
NCBI GTR	Genomic test codes	No	https://www.ncbi.nlm.nih.gov/gtr/
NCBI ClinVar	Genomic variations	No	http://www.ncbi.nlm.nih.gov/clinvar
NCIT	Cancer terminology	No	http://ncicb.nci.nih.gov/xml/owl/EVS/Thesaurus.owl
RxNorm	Medication codes	Yes	http://www.nlm.nih.gov/research/umls/rxnorm
Sequence Ontology	DNA change types	No	http://www.sequenceontology.org/
SNOMED CT	Disorders, body structures, findings, qualifiers	Yes	http://snomed.info/sct
UCUM	Units of measure	Yes	http://unitsofmeasure.org

Key:

• CPT - Current Procedural Terminology (American Medical Association)
• HGNC - Human Genome Organisation (HUGO) Gene Nomenclature Committee
• HGVS - Human Genome Variation Society
• HTA - HL7 Terminology Authority
• ICD - International Classification of Diseases (World Health Organization)
  • ICD-O-3 - Oncology, 3rd revision
  • ICD-10-CM - Clinical Modification, 10th revision
  • ICD-10-PCS - Procedure Coding System, 10th revision
• LOINC - Logical Observation Identifiers Names and Codes
• NCBI - National Center for Biotechnology Information (National Institutes of Health) (US)
  • NCBI GTR - Genomic Testing Registry
  • NCBI ClinVar - Not an acronym
• NCIT - National Cancer Institute (NCI) Thesaurus
• RxNorm - From National Library of Medicine (US)
• SNOMED CT - Systematized Nomenclature of Medicine Clinical Terms
• UCUM - Unified Code for Units of Measure
• UMLS - Unified Medical Language System Metathesaurus

Local Code Systems

Local code systems SnomedRequestedCS are provided for terms submitted but not yet published and/or approved by SNOMED. It is expected that the local codes will be replaced with approved LOINC and SNOMED terms in a future technical correction to the STU 2 IG. Where codes have already been assigned by SNOMED, but not yet published, those codes are used as local codes to reduce future changes. In other cases, the submission numbers are used as the local codes.

Links:

• Code systems defined in mCODE
• Value sets used in mCODE