SNOMED CT

What it is

SNOMED CT is a clinical terminology: a set of concepts with defined meaning that systems use to record clinical data in coded form. It is maintained by SNOMED International, an organization made up of member countries. According to SNOMED International, it is in use in more than eighty countries, and its International Edition, released every month, includes more than 360,000 concepts.

How it is built

Content is represented with three types of components:

• Concepts: each clinical meaning has a unique numeric identifier. The number carries no human-readable meaning.
• Descriptions: the terms people read. Each concept has a fully specified name (FSN), which states its meaning unambiguously, and synonyms.
• Relationships: they link each concept to others. The "is a" relationship connects it to more general concepts and forms hierarchies, such as clinical finding, procedure, observable entity, body structure or organism.

The International Edition contains the language-independent concepts and relationships. Countries can create national extensions when they need their own content. Reference sets (refsets) define subsets, translations and maps to other systems.

Licensing

• SNOMED International does not charge for the use of SNOMED CT in its member countries and territories.
• In non-member territories, use requires an affiliate licence, applied for every year through the MLDS service. Fees may apply depending on use and the territory's World Bank classification, and exemptions can be requested.
• As of October 2026, the Latin American members listed are Argentina, Chile, Costa Rica, El Salvador and Uruguay. Brazil and Mexico do not appear on the list.
• For non-affiliates, SNOMED International released the IPS Terminology in 2022, an open terminology limited to the scope of the IPS. Those who already hold a full licence should use a full edition of SNOMED CT.

Common misconceptions

• SNOMED CT does not replace ICD. SNOMED CT is for detailed clinical recording; ICD is a classification for statistics and reporting.
• The SNOMED CT to ICD-10 map is a coding aid. SNOMED International makes clear that it does not fully automate coding and is not optimized for billing.
• "Free" depends on the country. What is free in a member country can require a licence and fees in another.
• The code cannot be read at a glance. You have to read the FSN and the concept's position in the hierarchy.
• Editions change every month, and a concept can become inactive: it is no longer intended for current use, although it stays in the files as a historical record. State which edition and version you use.