Regenstrief Institute and SNOMED International are pleased to announce the release of LOINC Ontology Version 2.83. This ongoing joint initiative aims to deliver seamless interoperability between LOINC and SNOMED CT by linking LOINC concepts with SNOMED CT’s clinical ontology.
A new project home
To streamline access, maintenance, and support, the primary home for the LOINC Ontology has moved from loincsnomed.org to loinc.org/ontology. This new location serves as the central hub for downloads, documentation, and the LOINC Ontology browser. Existing links from loincsnomed.org will automatically redirect.
Expanded concept coverage
LOINC Ontology v2.83 is aligned with the July 1, 2026 International Release of SNOMED CT and LOINC Version 2.83, released August 24, 2026. Released in the 11010000107 |LOINC Extension module using standard SNOMED CT RF2 format, the includes over 46,000 SNOMED CT concepts representing active and discouraged laboratory LOINC terms.
Coverage among the most frequently used LOINC concepts includes:
- 99 of the top 100 most used laboratory concepts
- 1,759 of the top 2,000 most used laboratory concepts
- 15,591 of the Top 20,000 most used LOINC concepts
Key modeling updates
This release continues to advance laboratory observable modeling to enhance data quality, clinical accuracy, and cross-system exchange. Major updates in version 2.83 include expansions in genetic microbiology post-coordination concepts, restructuring of drug and toxicology analytical methods, standardization of gene mutation representations, and property alignments across microbiology classes. Details on these updates are available in the technical release notes.
Explore and download
Visit loinc.org/ontology to access release files, view technical documentation, and launch the browser. We continue to welcome feedback from implementers and community members as we continue to advance this project.