Table Of Contents

Introduction

SNOMED CT terminology provides a common language that enables a consistent way of indexing, storing, retrieving, and aggregating clinical data across specialties and sites of care.

The International Health Terminology Standards Development organisation (IHTSDO^®), trading as SNOMED International, maintains the SNOMED CT technical design, the content architecture, the SNOMED CT content (includes the concepts table, the descriptions table, the relationships table, a history table, and ICD mappings), and related technical documentation.

The SNOMED CT Irish Extension - packages these components for release every April and October, to be used with the latest SNOMED CT International Edition release.

The same content can be viewed online using the SNOMED CT browser, and eHealth Ireland website

Background

This document provides a summarized description of the content changes included in the December 2025 Production release of the SNOMED Clinical Terms^® Managed Service Ireland Extension package.

It will also include technical notes detailing the known issues which have been identified (should any of these exist). These are content or technical issues where the root cause is understood, and the fix has been discussed and agreed, but has yet to be implemented.

This Ireland Extension package is dependent upon, and should therefore be consumed in conjunction with the SNOMED CT® December 2025 International Edition release.

Scope

This document is written for the purpose described above and is not intended to provide details of the technical specifications for SNOMED CT or encompass every change made during the release.

Content Development Activity

Summary

Content from the SNOMED CT® December 2025 International Edition release has been included, alongside additional components for use in Ireland. 

This extension contains concepts, relationships and reference sets for healthcare professionals. 

New and Updated Content

This is the 13th SNOMED CT Irish Edition Production release.

IE National Drug Extension

Medicinal product content includes development across the SNOMED International Drug Model and the Irish Drug Extension Model. The National Drug Extension continues to be developed.

Due to the volume of content, this will occur across several releases and release notes will be updated when this work reaches stability/maintenance levels. Ahead of this, please note that content in the Irish drug extension should be considered partial against the range of medicinal products available to be used in clinical care in Ireland.

Table 1: Summary of Drug Content since last release.

IE Clinical Content

New and updated content

Concept statistics

The SNOMED Irish National Release Centre published 1 new concepts and 0 new reference sets for December 2025

New Reference sets

No new Reference sets for December 2025

Reference Set changes

Table 2.0. Reference set changes

Table 2.1 Content Sent from Irish NRC to SNOMED International for promotion

Table 2.2 Content sent from Irish NRC to SNOMED International for authoring

Technical notes

Known Issues

Known Issues are content or technical issues where the root cause is understood, and the resolution has been discussed and agreed but has yet to be implemented.  This can be due to a number of reasons, from lack of capacity within the current editing cycle, to the risk of impact to the stability of SNOMED CT if the fix were to be deployed at that stage in the Product lifecycle.

The following known issues were identified:

Resolved Issues

Resolved Issues are those where the resolution has been discussed and agreed, and has been implemented in time for this release. 

Changes for October 2025

Monthly Releases

The NRC has moved to monthly releases since October 2025, this December release is the second of these monthly releases.

Refset File Naming conventions

The new naming conventions for additional reference sets files have been applied to the Ireland Extension release package from the October 2025 IE Managed Service Release onwards. The new convention updates the file names to use RefsetID prefixes instead of the old human readable format, in order to improve maintainability and allow for machine reading of the file names. However, this convention will ONLY be applied to additional refsets, and not core refsets such as Language refset, Association refset, MRCM refset files, etc. (as these were considered to incur too high an impact on end users if the naming conventions were to be changed)

So, for example, in the October 2025 IE Managed Service Release the additional refset file names have changed from:

• “der2_Refset_AntimicrobialStewardshipPerformanceIndicatorMeasurementSystemApimsDataSetSimpleRefsetFull_IE1000220_20250421.txt”

  • to:

• “der2_Refset_74921000220101SimpleRefsetFull_IE1000220_20250421.txt”

The file name of the Association reference set has been aligned with the naming convention used in the International Edition. Please refer to the Terminology Release Advisory Group discussion page for details: Association Reference naming convention

• “der2_cRefset_AssociationReferenceFull_IE1000220_20250421.txt”

  • to:

• “der2_cRefset_AssociationFull_IE1000220_20250421.txt”

Notice of changes to the IE Extension Release package

In line with the refined implementation of Annotations, we are updating all Extensions in order to align them with the updated version of the refsets in the International Edition Release package (which were first published in June 2024).

• The languageCode field was specified as the two characters of ISO-639-1 code for the language of the annotation text. The change includes support for specifying dialect when it is applicable by adhering to RFC 5646, which allows the combination of two characters of ISO 639-1 code and two uppercase letters of country code (ISO 3166) separated by a hyphen.  The changes apply to both the Member Annotations String Value Reference Set + Component Annotation String Value reference set:

  • The column "languageCode" has therefore been changed to "languageDialectCode".

    • Component Annotations (1292992004)

      • OLD:    id    effectiveTime    active    moduleId    refsetId    referencedComponentId    languageCode    typeId    value

      • NEW:   id    effectiveTime    active    moduleId    refsetId    referencedComponentId    languageDialectCode    typeId    value

    • Member Annotations (1292995002)

      • OLD:   id    effectiveTime    active    moduleId    refsetId    referencedComponentId    referencedMemberId    languageCode    typeId    value

      • NEW:  id    effectiveTime    active    moduleId    refsetId    referencedComponentId    referencedMemberId    languageDialectCode    typeId    value