September 2026 SNOMED CT US Edition Available for Download

The National Library of Medicine (NLM) is pleased to announce that the September 2026 U.S. Edition of SNOMED CT is available for download. This release contains 286 new active concepts specific to the U.S. Extension. The September 2026 U.S. Edition of SNOMED CT is based on the content published in the July 2026 SNOMED CT International Edition.

Announcement - Changes in the September 2026 U.S. Edition release

• Increase to the maximum length of Description Types.

The maximum length of Fully Specified Name (FSN) and Synonym descriptions have been increased from 255 to 4,096 characters starting from the July 2026 release of the International Edition (upon which this September 2026 U.S. Edition release is dependent). The requirement for this change came from the Pharmaceutical/biologic product hierarchy, where the terming guidance for FSNs caused the previous limit to be exceeded where there is a large number of ingredients in a medicinal product, which is particularly common in multivalent vaccines.

Although the July 2026 International Edition introduces this new capability, no descriptions were actually extended beyond 255 characters in that release; the change serves as an enabler for future editions. The September 2026 U.S. Edition, therefore, contains only the configuration change, and not actual records exceeding the original limit. The actual implementation of the change will be reflected in the March 2027 U.S. Edition release (as this will be dependent on an International version greater than the August 2026 International Edition), which will feature the first descriptions exceeding the previous 255 character limit. For further information, please refer to the International Edition release notes. 

From the March 2027 U.S. Edition release onwards, FSNs, Synonyms, and Descriptions may reach a length of up to 4,096 characters. It is important to note that no further warnings regarding this change will be issued. Users and implementations must be prepared to process content of this length in any release following the March 2027 U.S. Edition.

NOTE: Future description changes or additions will align with the updated specification of description length up to 4,096 characters without early visibility of these changes.

• Notice of Deprecation - Concept Non Current Indicators.

As planned, Concept Non Current (CNC) indicators were deprecated in the January 2026 International Edition of SNOMED CT. A total of 111 CNC indicators remained active following the January 2026 International Edition release. These have been inactivated in the February 2026 International Edition release.

The addition of CNC indicators to active descriptions on inactive concepts has now ceased. Inactive CNC indicators will be left in place as inactive components. This deprecation is not expected to have any impact on existing SNOMED CT implementations but will instead simplify the product and reduce associated maintenance costs.

For further information, please see the Notice of Deprecation.

To download the above releases, you must agree to the UMLS Metathesaurus License and have a UMLS Terminology Services login. Please see the SNOMED CT License page for additional information to learn more about the license and sign up for an account. Any inquiries may be sent to the NLM Customer Support.

Want to learn more about SNOMED CT? Please visit our SNOMED CT Learning Resources page.

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