Table of Contents: 2026 MARCH - APRIL No. 469
March 2026 SNOMED CT US Edition available for download. NLM Tech Bull. 2026 Mar-Apr;(469): b2
The National Library of Medicine (NLM) is pleased to announce that the March 2026 US Edition of SNOMED CT is available for download. This release contains 114 new active concepts specific to the US Extension. The March 2026 US Edition of SNOMED CT is based on the content published in the January 2026 SNOMED CT International Edition.
• 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 here.
• 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, where the 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. Considering feedback received from stakeholders, the proposed changes will be implemented in July 2026.
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. 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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