Introducing the LOINC Ontology: A LOINC and SNOMED CT Interoperability Solution

Visit dedicated website for more information

The international standard for identifying health measurements, observations, and documents.

Reference labs, healthcare providers, government agencies, insurance companies, software and device manufacturers, researchers, and consumers from around the globe use LOINC to identify data and move it seamlessly between systems.

It’s free, but invaluable.

Find quick answers in our Knowledge Base.
LOINC 30th Anniversary

2023 LOINC Conference

Recordings and slides from our recent event in Atlanta and online are now available.

New Community Forum

We have launched a new version of our forum where you can ask questions and participate.

New LOINC mapping guides

We have created six new guides for using LOINC terms across numerous laboratory domains.


Find LOINC concepts in your browser with this powerful web app. A free LOINC login is required.

Hierarchy Browser

Instead of searching, peruse LOINC codes via numerous hierarchies. A free LOINC login is required.

Community Forum

Ask questions and chime in on conversations with your fellow LOINCers.

Request a LOINC

Cannot find an appropriate LOINC concept? Follow instructions for requesting a new code.

Submission Queue

See all the new concepts we are working on now, including any submissions you may have made.