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News and events / NCTS Communique: SNOMED CT Description Length Increase – Important Information for Implementers

NCTS Communique: SNOMED CT Description Length Increase – Important Information for Implementers

Sep 2, 2026

Following consultation undertaken in 2024, the Agency would like to advise of a change to SNOMED CT description lengths that may impact organisations that implement SNOMED CT-AU (or other SNOMED CT editions or extensions) descriptions natively.

What is happening

In the July 2026 release of the International Edition of SNOMED CT from SNOMED International, the maximum length of Fully Specified Name (FSN), Synonym, and Preferred Term descriptions has increased from 255 characters to 4096 characters.

Descriptions exceeding 255 characters are planned to be introduced from the August 2026 international release onwards.

This change was driven by requirements within the pharmaceutical / biologic product hierarchy, where FSN terming guidance can result in description lengths exceeding the previous limit, particularly for medicinal products containing a large number of ingredients, such as multivalent vaccines.

Within the Australian Extension (SNOMED CT-AU), the standard description type specification was extended to 2048 characters in 2014, and currently all concept descriptions in the Australian Extension including the Australian Medicines Terminology (AMT) remain below this limit. There is no impact in the August 2026 release of SNOMED CT-AU. However, future releases may contain descriptions, including FSNs, Synonyms, and Preferred Terms of up to 4096 characters.

What you need to do

Organisations that implement SNOMED CT-AU (or other SNOMED CT editions or extensions) descriptions should:

  • Review and assess their systems for any limitations relating to SNOMED CT/ SNOMED CT-AU description lengths.
  • Confirm that databases, interfaces, validation rules, APIs, and downstream systems can accommodate description lengths of up to 4096 characters.
  • Consider any potential impacts to display, integration, and reporting functions that currently assume shorter description lengths.

While there is no immediate impact expected in the August 2026 release, proactive assessment and planning are recommended to ensure future compatibility. The NCTS FHIR API and the Ontoserver terminology server software are not expected to be affected by these changes.

Where to get further support

If you have any questions or would like further information, please contact the NCTS Team at help@digitalhealth.gov.au.