Table Of Contents

Introduction

Background

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

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.

Purpose

This document provides a summarized description of the content changes included in the January 2026 release of SNOMED Clinical Terms^® (SCT) International Edition.

It also includes notes detailing the known content or technical issues where the root cause is understood, the fix has been discussed and agreed to, but has yet to be implemented.

The SNOMED International release notes are available alongside the January 2026 International Edition.

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.

Audience

The audience includes National Release Centers, WHO-FIC release centers, vendors of electronic health records, terminology developers and managers who wish to have an understanding of changes that have been incorporated into the January 2026 International Edition.

Please note, you may have to register for a user account in order to access the links included in these release notes.

Content Development Activity

Summary

Continuous quality improvement and enhancement of existing content is an ongoing process undertaken by SNOMED International in preparation for every release. The January 2026 International Edition has seen a continuation of the work driven by contributions from: Kaiser Permanente i.e. Convergent Medical Terminology (CMT), Global Medical Device Nomenclature Agency (GMDNA), Orphanet and other domain specific collaborations as well as requests received via the Content Request System (CRS). 

Additionally quality improvement activities are advanced via project driven initiatives summarized below.  Additional work items impacting every release are updates to the SNOMED CT derived maps such as ICD-10 and ICD-O; details are included in these release notes.  

Information about editorial decisions may be found in the SNOMED CT Editorial Guide; mapping guidance for ICD-10 can be found here.

Quality Assurance

Update 446030004 | Angiography using contrast (procedure)

The concept 446030004 | Angiography using contrast (procedure) | has been reviewed and corrected. The FSN of this concept does not specify arterial or venous angiography, however, the concept previously included the synonym “Arteriography” and was modeled with procedure site 51114001|Arterial structure (body structure)|.

The following changes have been implemented:

• The procedure site for 446030004 | Angiography using contrast (procedure) | has been updated to 59820001|Blood vessel structure (body structure)|

• The synonym “Arteriography” has been inactivated from this concept.

• A new arterial-specific concept has been added 1381951005 | Angiography of artery using contrast (procedure) |

Update 260379002|Impaired (qualifier value)|

The concept 260379002 |Impaired (qualifier value)| has had an additional parent of 263654008 |Abnormal (qualifier value)| added. This has resulted in the removal of a large number of redundant Interpretation/Has interpretation role groups and the addition of "Abnormal X system function" parents to function related clinical findings.

Update 46621007 |Atelectasis (disorder)|

New synonyms have been added to 46621007 |Atelectasis (disorder)|

• Non-expanded lung

• Under expanded lung

• Unexpanded lung

These descriptions have been inactivated on 54959009 |Perinatal atelectasis (disorder)|.

54959009 |Perinatal atelectasis (disorder)| has been remodeled with perinatal occurrence 1156684004 |Fetal antepartum and/or intrapartum and/or early neonatal period (qualifier value)| and morphology 16277007|Collapse (morphologic abnormality)|. Synonyms referring to ‘congenital’ have been inactivated as this is not equivalent to perinatal.

The following concepts were also updated as part of this work:

• 111466004 |Perinatal partial atelectasis (disorder)|

• 42908004 |Perinatal primary atelectasis (disorder)|

• 59113005 |Perinatal secondary atelectasis (disorder)|

Bulk Update MOVED TO Associations

Continuing the work done to inactivate content in the Navigational Hierarchy, MOVED_TO associations that were connected to the Navigational Hierarchy inactivations have been updated to align with SNOMED International editorial guidance for concept inactivation.

Body Structure 

Update 279390002|Intracranial nerve structure (body structure)|

Approximately 20 new concepts representing intracranial segments of cranial nerves have been added to support the modeling of intracranial procedures on cranial nerves, nerve roots, and ganglia. The existing subtypes of 279390002|Intracranial nerve structure (body structure)| have been reviewed and revised.

Number of concepts edited (approx): 34

SEP and Laterality Anatomy Reference Sets

The release file for the lateralizable body structure reference set has been updated and validated.

The release file for the SEP reference set has been updated and validated.

Clinical Finding

Update Cirrhosis

A new concept 1381616004 |Cirrhosis (morphologic abnormality)| has been created as a subtype of 64770007 |Nodular regeneration (morphologic abnormality) and 57977008 |Chronic fibrosis (morphologic abnormality)|. It is now used in the definition of the cirrhosis disorder concepts (approximately 60), appearing in a single role group whereas previously their definition included two role groups (one with 64770007 |Nodular regeneration (morphologic abnormality)| and one with 57977008 |Chronic fibrosis (morphologic abnormality)|).

Number of concepts edited (approx): 60

Update Glomerular Hematuria

The model and descriptions for expected subconcepts of new concept 1381566001 |Hematuria due to glomerular disease (disorder)| have been updated with the addition of

• 1381825007 |Diffuse membranous glomerulonephritis (disorder)|

• 1381893005 |Diffuse mesangiocapillary glomerulonephritis (disorder)|

• 1381892000 |Diffuse mesangial proliferative glomerulonephritis (disorder)|

GCI axioms have been added to 1148903009 |Secondary disorder of glomerulus (disorder)|.

This enhancement aims to improve the classification of glomerular disorders resulting from medications and infections.

Number of concepts edited (approx): 42

Situation with Explicit Context

Update 443938003|Procedure carried out on subject (situation)|

After consultation with this briefing note and review of the feedback received, the concepts in the hierarchy 443938003|Procedure carried out on subject (situation)| will not be inactivated and have instead been remodeled to define them with their procedure hierarchy counterparts (where possible).

Qualifier Value

Update American Joint Committee on Cancer

In collaboration with the American Joint Committee on Cancer (AJCC) the following updates have been made:

• A new AJCC IG (Intermediate Grade) concept has been added to represent an additional grade category introduced by AJCC. This value has been placed under the existing clinical, pathological, and yp grade parent concepts.

• 1381897006 |American Joint Committee on Cancer grade IG (qualifier value)| has been added

• A new yc grade grouper concept has been created to align with the existing grade structure and to serve as the parent for the grade concepts (e.g., G1, GX, GB, (new) IG, etc.).

• 4 prefixes c, p, yc, and yp have been added as children of 1370921001 |American Joint Committee on Cancer allowable prefix and/or suffix value (qualifier value)|

Number of concepts edited (approx): 11

Update Subtype of 260245000 |Finding value (qualifier value)|

7389001 |Time frame (qualifier value)| has been made a subtype of 260245000 |Finding value (qualifier value)|. This means << 7389001 |Time frame (qualifier value)| are now within the range of the Has Interpretation attribute.

Rationalization of Units of Measure Concepts

Following consultation with DEUSG, two overlapping sub-hierarchies have been updated:

• 732935002 |Unit of presentation (unit of presentation)|

• 408102007 |Unit dose (qualifier value)|.

The current drug model only uses Unit of presentation to model Clinical Drug concepts. Duplicates exist across the two sub-hierarchies both subtypes of 767524001 |Unit of measure (qualifier value) |, causing potential ambiguity and inconsistent modeling.

• 41 duplicate unit of product usage concepts have been inactivated.

• 8 new 'unit of presentation' concepts were created as replacement values

• 2 concepts were inactivated with reason outdated and no replacement

A small number of unit of product usage concepts where these are not Units of presentation (e.g. scoop, spray, puff, drop, teaspoonful) have been retained for future review.

For further information, please see this briefing note.

Number of concepts edited (approx): 43

Collaboration/Harmonization Agreements

Convergent Medical Terminology (CMT)

7 new concepts have been added for the January 2026 release.

Orphanet

Working in collaboration with Orphanet efforts are ongoing to update rare disease concepts in SNOMED CT to maintain alignment with Orphanet for the annual update of the SNOMED CT to Orphanet Maps. This map is at disorder level. In scope content has been annotated with attribution to Inserm Orphanet.

All of the concepts added for the Orphanet project have been mapped to ICD-10.

Cancer Synoptic Reporting

Cancer synoptic reports are used by many member countries to record pathology examination of cancer specimens including the College of American Pathologists (US and Canada), Royal College of Pathology (UK), Royal College of Pathology Australasia (Australia, New Zealand), PALGA (The Netherlands), Swedish Society of Pathology, and others.

For more information about this project, please see Cancer Synoptic Reporting Clinical Project Group 

International League Against Epilepsy (ILAE)

In line with approved harmonized terminology, this project is working on alignment including restructuring to update the hierarchy  << 313307000 |Epileptic seizure (finding)|.

Concepts in the areas << 79745005 |Reflex epilepsy (disorder)|and << 1363250001 |Acute symptomatic epileptic seizure (finding)| have been reviewed and updated with actions including

• Inactivation of outdated components

• Creation of new concepts

• Updated descriptions to align with current disorder naming

• Addition of definitions

• Attributions to the International League Against Epilepsy

A decision has been made to accept the addition of five new ‘unknown onset’ concepts e.g., 1365928006 |Epileptic spasms of unknown onset (finding)| to support epilepsy recording requirements. These concepts include definitions and attribution to the International League Against Epilepsy.

Attributions have also been added to concepts with definitions which were previously added for this project, as well as existing concepts which had significant modeling changes and a definition added as part of the project work.

Further information about this collaboration is available here.

Internal Quality Improvement

Machine Readable Concept Model (MRCM) Changes

No changes have been made for the MRCM in the January 2026 International Edition.

Future changes that are currently in progress can be viewed via the MRCM Daily Build Browser

Please see Early Visibility Release Notifications for future planned changes to MRCM.

Annotation Reference Set

The addition of content for the Annotations refset was commenced in the July 2024 International Edition release and is ongoing for attribution of in scope content that is part of a collaboration agreement. Where content with attribution no longer falls into scope for a collaboration agreement, the attribution has been inactivated.

SNOMED CT derived products

SNOMED CT - ICD-10 map

The SNOMED CT to the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (© World Health Organization 1994) 2016 Version map (SNOMED CT to ICD-10 Map) is included in the SNOMED CT International Edition as a Baseline. The SNOMED CT to ICD-10 Map was created to support the epidemiological, statistical and administrative reporting needs of SNOMED International member countries and WHO Collaborating Centers.

The SNOMED CT to ICD-10 Map is released in Release Format 2 (RF2) only. It is located in the file der2_iisssccRefset_ExtendedMapFull_INT_20200731.txt, which is in the Map folder under Refset, in each of the three RF2 Release Type folders. 

The SNOMED CT to ICD-10 Map is released as Refset 447562003 |SNOMED CT to ICD-10 extended map (foundation metadata concept).

The ICD-10 Mapping Technical Guide (including exemplars) is here.

Content Development Activity Summary

The map is a directed set of relationships from SNOMED CT source concepts to ICD-10 target classification codes.  The SNOMED CT source domains for the map are constrained to subtypes of 404684003 |Clinical finding (finding)|, 272379006 |Event (event)|, and 243796009 |Situation with explicit context (situation)|. The target classification used is the ICD-10 WHO version 2016 (https://icd.who.int/browse10/2016/en#/).

The map provided for this release has been updated and represents a complete map from the January 2026 release of the SNOMED CT International Edition to the ICD-10 WHO version 2016.

This includes:

Mapped content for January 2026 release

• Addition of 109 new mapped concepts

• Updates to 134 existing mapped concepts

• Retirement of 68 mapped concepts

The SNOMED CT to ICD-O morphology map has no additional new content for this release.

We welcome feedback on any issues that users may detect when deploying the map. Issues can be reported to mapping@snomed.org.

SNOMED CT to OWL conversion and classification

The repository containing the toolkit enabling simple SNOMED CT to OWL conversion and classification can be found here, including documentation on its use: https://github.com/IHTSDO/snomed-owl-toolkit

Please contact SNOMED International at support@snomed.org if you would like to provide any feedback on ways to extend and improve the new toolkit.