The ConceptMap resource in FHIR defines a mapping from one set of concepts defined in a code system (“source”) to one or more concepts defined in other code systems (“target”).

We have created the following bidirectional concept maps and will continue to add to these over time.

In the examples below, calling the ConceptMap resource directly gives you back the whole resource entry for the specified set. This will give you all the ConceptMap metadata, the mappings, etc. Each ConceptMap resource is referenced using its canonical URI.

Equivalence

Each individual map has an equivalence value that indicates whether the source and target concepts are equivalent or whether one is broader or narrower in meaning than the other. Note that FHIR defines the equivalence as going from the target concept to the source, so if the equivalence value is “narrower”, that means the target concept is more specific than the source concept.

For example, LOINC 30657-1 (MR Brain WO contrast) is mapped to RPID479 (MR Head wo IV contrast) with equivalence “equivalent” while the same LOINC term is mapped to RPID593 (MR Head wo IV contrast Pediatric) with equivalence “narrower”, because RPID593 is specific for pediatric patients.

https://fhir.loinc.org/ConceptMap/$translate?system=http://loinc.org&code=30657-1

Note the LOINC TS uses the R4 version of FHIR which has different (and more ambiguous) equivalence types than subsequent versions.

Get the mapping for a particular LOINC Code

Use the $translate operation to find a mapping for a particular source term.

https://fhir.loinc.org/ConceptMap/$translate?system=http://loinc.org&code=11556-8

Available ConceptMaps

LOINC terms ↔ IEEE device codes

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-to-ieee-11073-10101
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/ieee-11073-10101-to-loinc

LOINC terms ↔ RadLex Playbook procedure codes (RPIDs)

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-to-radlex
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/radlex-to-loinc

LOINC Parts ↔ RadLex clinical terms (RIDs)

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-parts-to-radlex
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/radlex-to-loinc-parts

LOINC Parts ↔ RxNorm terms

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-parts-to-rxnorm
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/rxnorm-to-loinc-parts

LOINC Parts ↔ PubChem terms

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-parts-to-pubchem
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/pubchem-to-loinc-parts

LOINC Parts ↔ SNOMED CT terms

It is important to note this is the LOINC Parts to SNOMED CT mapping created circa July 2017. These concept maps will be replaced by the current LOINC Ontology work.

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-parts-to-snomed-ct
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/snomed-ct-to-loinc-parts

LOINC terms ↔ PhenX concepts

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-to-phenx
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/phenx-to-loinc

LOINC terms ↔ CMS Long-term Post-acute care (LT-PAC) assessment concepts

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-to-cms-irf-pai
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/cms-irf-pai-to-loinc
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-to-cms-lcds
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/cms-lcds-to-loinc
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-to-cms-mds
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/cms-mds-to-loinc
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-to-cms-oasis
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/cms-oasis-to-loinc

LOINC Parts ↔ ChEBI concepts

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-parts-to-chebi
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/chebi-to-loinc-parts

LOINC Parts ↔ NCBI ClinVar concepts

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-parts-to-ncbi-clinvar
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/ncbi-clinvar-to-loinc-parts

LOINC Parts ↔ NCBI Gene concepts

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-parts-to-ncbi-gene
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/ncbi-gene-to-loinc-parts

LOINC Parts ↔ NCBI Taxonomy concepts

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-parts-to-ncbi-taxonomy
https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/ncbi-taxonomy-to-loinc-parts

ConceptMap versions

You can supply a version paramater to the ConceptMap identifier to retrieve past versions. 

https://fhir.loinc.org/ConceptMap/?url=http://loinc.org/cm/loinc-parts-to-chebi&version=2.82