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Table of Contents: 2025 SEPTEMBER - OCTOBER No. 466

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September 2025 SNOMED CT US Edition Available for Download

September 2025 SNOMED CT US Edition Available for Download. NLM Tech Bull. 2025 Sep-Oct;(466):b1.

2025 September 02 [posted]

The National Library of Medicine (NLM) is pleased to announce that the September 2025 US Edition of SNOMED CT is available for download. This release contains 328 new active concepts specific to the US Extension. The September 2025 US Edition of SNOMED CT is based on the content published in the July 2025 SNOMED CT International Edition.

Announcement - Changes in the September 2025 US Edition release 

  • JSON file

A metadata file called "release_package_information.json" has been added to the US Edition package to provide additional information on the Release's contents. It can be found directly in the main package.
The data included so far is mostly based on additional information on the package structure and its contents, but it also includes data describing the language refsets included in the release, etc.
  • Reminder of SNOMED International proposal to increase description character limit

SNOMED International, owners of SNOMED CT, propose to increase the maximum length of Fully Specified Name (FSN) and Synonym descriptions from 255 characters to 4096 characters. The requirement for this change has come from the Pharmaceutical/biologic product hierarchy. Terming guidance for FSNs causes the current limit to be exceeded where there is a large number of ingredients in a medicinal product, which is particularly common in multivalent vaccines.

Implementers are likely to have hardcoded database schemas to 255 characters, so a significant lead time is proposed before this change takes effect. The proposed changes will be implemented in July 2026 based on feedback received from stakeholders.

It is important to note that there is absolutely no intention to increase the length of a multitude of the International Descriptions. The proposal is simply to increase the maximum possible size to 4096 to allow a small number of necessarily longer terms to be consumed. However, most Descriptions will remain at their current length, well below 255 characters.

Please see the latest Q&A blog post by SNOMED International Technical Specialist Peter Groves Williams, who explains the proposed change, its potential benefits, the feedback process and timelines, and the issues that may need to be considered in such an update. You can also find the full proposal here.
 
To download the above releases, you must agree to the UMLS Metathesaurus License and have a UMLS Terminology Services login. To learn more about the license and to sign up for an account, please see the SNOMED CT License page for additional information. 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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