By Dr. Linda Vidone, Chair of Diagnostic Terminology SWG

Need a brief refresher on what SNOMED CT terms are and how they work? We’ve got you covered. Take a few minutes to brush up on the coding system with our SNOMED CT 101 guide.

What is SNOMED CT? “The Global Language of Healthcare”

SNOMED CT® stands for Systemized Nomenclature of Medicine – Clinical Terms. It is a standardized, international, multilingual core set of clinical healthcare terminology that can be used in electronic health records (EHRs). SNOMED International is the non-profit standards development organization that creates and distributes SNOMED CT, and the International Health Standards Development Organization operates it.

Why is SNOMED CT used?

SNOMED CT represents coded terms that may be used within EHRs to capture, record, and share clinical data for use in healthcare organizations. It is a crucial component supporting solutions that enable the retrieval of meaningful clinical information. SNOMED CT terms, or codes, have been used internationally for years. They became widely used in the United States after 2013, when the federal government required EHRs to include the terminology in their systems to comply with Stage 2 of Meaningful Use.

How is SNOMED CT maintained?

SNOMED International continuously updates content mainly based on user needs and feedback. Recently, SNOMED converted to monthly releases of the SNOMED CT International.

The US Edition, which can be obtained from the US National Library of Medicine, provides a single source of SNOMED CT content for use in the United States. The SNOMED CT US Edition is a standalone release that contains the content of both the US Extension and the International Editions of SNOMED CT.

What do the codes look like?

SNOMED CT codes are numerical and are a minimum of six digits long. For instance, 33885009 is the unique code for the SNOMED concept restoration, crown, and porcelain/ceramic substrate (procedure).

How is the terminology organized?

There are four primary categories of SNOMED CT: concepts, descriptions, relationships, and reference sets:


Concepts, or terms, are represented by unique codes and human-readable descriptions. Each concept is a unique, clinically relevant thought across a wide range like an abscess, zygote, measurement procedure, or substance. Currently, SNOMED CT contains approximately 352,567 concepts and is organized by relationships into hierarchies that range from general to detailed.


Descriptions are human-readable terms linked to concepts. Concepts can have multiple descriptions, each of which is a synonym of the original idea.


To provide meaning to SNOMED concepts, SNOMED uses relationships between concepts to provide formal definitions and organization. For instance, the SNOMED concept of viral pneumonia has a defining relationship between type and infective pneumonia.


Reference sets are used to customize a version of SNOMED CT or to provide a collection of SNOMED concepts. Examples of reference sets are:

The designation of language preferences for specific terms, mapping to other code systems, and a collection of concepts relevant to a medical specialty.

The members of the Diagnostic Terminology SubWorkGroup are active participants during the SNOMED meetings. In addition to these meetings, our group is also actively involved in the SNOMED international Dentistry Clinical Reference Group (CRG), which provides advice and guidance to ensure that the SNOMED CT dentistry context meets the needs of users globally, is in line with clinical practice and is implementable in dentistry information systems. This group meets bi-monthly and is led by Dr. Mark Jurkovich.

For additional information

I hope you will find our information interesting and valuable. We welcome your feedback and suggestions for future newsletters. You can contact our staff liaison Timothy L. Brown at or 972-458-6998 x104.

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