SNOMED CT, US Edition

Last uploaded: March 22, 2026

Details

Acronym	SNOMEDCT
Visibility	Public
Description	The US Edition of SNOMED CT combines the International Release of SNOMED CT and the US Extension of SNOMED CT SNOMED CT provides the core general terminology for the electronic health record (EHR). The concepts have unique meanings and formal logic-based definitions organized into hierarchies. Each International Release includes the core of the terminology (concepts, descriptions, and relationships), together with works to support the implementation and use of SNOMED CT, including subsets, cross maps to existing classifications and coding schemes, and an extensive set of guidelines. The US Extension to SNOMED CT included the concepts, descriptions, and relationships accepted by NLM as a formal extension to the SNOMED CT International Release. NLM no longer releases the standalone US Extension. The US Edition of SNOMED CT includes more than 300,000 unique concepts. There are over 1,000,000 descriptions in SNOMED CT, including synonyms that can be used to refer to a concept. In addition, there are approximately 903,000 links or semantic relationships between the SNOMED CT concepts.
Status	Production
Format	UMLS
Categories	Health
Groups	Unified Medical Language System
License Information	This ontology is made available via the UMLS. Users of all UMLS ontologies must abide by the terms of the UMLS license.

Alternative name	SNOMEDCT_US See more...
Bibliographic reference	http://www.snomed.org http://www.snomed.org
Contact	Nlm Customer Service ([email protected])
Creation date	November 3, 2025
Deprecated	false See more...
Documentation	https://www.nlm.nih.gov/healthit/snomedct/us_edition.html See more...
Homepage	http://www.snomed.org See more...
Imports	http://www.w3.org/2004/02/skos/core http://www.w3.org/2004/02/skos/core
Notes	RDF Version of the UMLS ontology SNOMEDCT_US; converted with the UMLS2RDF tool (https://github.com/ncbo/umls2rdf), developed by the NCBO project. See more...
Object creation date property	http://purl.org/dc/elements/1.1/created http://purl.org/dc/elements/1.1/created
Object modification date property	http://purl.org/dc/elements/1.1/modified http://purl.org/dc/elements/1.1/modified
Source	UMLS 2025AB See more...
Submission date	March 22, 2026
Syntax	http://www.w3.org/ns/formats/Turtle http://www.w3.org/ns/formats/Turtle
Version information	2025_09_01 See more...
uri	http://purl.bioontology.org/ontology/SNOMEDCT/ http://purl.bioontology.org/ontology/SNOMEDCT/

Version	Released	Uploaded
2025_09_01 (Parsed, Indexed, Metrics, Annotator, Error Diff)	11/03/2025	03/22/2026
2025_03_01 (Archived)	05/06/2025	03/19/2026
SNOMEDCT_US_2024_09_01 (Archived)	11/04/2024	01/16/2025
2024AA (Archived)	05/06/2024	08/28/2024
2023AB (Archived)	11/06/2023	01/31/2024
2023AA (Archived)	04/01/2023	08/07/2023
2022AB (Archived)	11/07/2022	01/06/2023
2022AA (Archived)	05/02/2022	06/10/2022
2021AB (Archived)	11/01/2021	11/18/2021
2021AA (Archived)	04/03/2021	05/20/2021
2020AB (Archived)	11/02/2020	01/06/2021
2020AA (Archived)	05/04/2018	09/24/2020
2019AB (Archived)	11/04/2019	11/18/2019
2019AA (Archived)	05/06/2019	08/27/2019
2018AB (Archived)	11/05/2018	04/29/2019
2018AA (Archived)	05/07/2018	07/06/2018
2017AB (Archived)	11/06/2017	07/06/2018
2017AA (Archived)	05/08/2017	04/06/2018
2016AB (Archived)	02/06/2017	02/06/2017
2016AA (Archived)	09/06/2016	09/06/2016
2015AB (Archived)	07/20/2016	07/20/2016
2015AA (Archived)	06/09/2015	06/09/2015
2014AB (Archived)	01/29/2015	01/29/2015
2014AA (Archived)	02/21/2014	02/21/2014
2013AA (Archived)	02/18/2014	02/18/2014
2013AA (Archived)	01/14/2014	01/14/2014
2013AA (Archived)	05/08/2013	09/25/2013
2011_01_31 (Archived)	01/31/2011	08/11/2011
2010_07_31 (Archived)	07/31/2010	11/09/2010
2010_01_31 (Archived)	01/31/2010	05/12/2010
2009_07_31 (Archived)	07/31/2009	01/05/2010
2009_01_31 (Archived)	01/31/2009	07/31/2009
more...

CCC Nursing Ontology: This is nursing diagnosis ontology of Clinical Care Classification
Cardiac-centered Frailty Ontology: This ontology is designed to cover the portions of reality relevant to assessing patient frailty. While we believe it to be relevant to frailty in general, during its development we were specifically focused on decisions relating to cardiac care. We gathered terms using existent instruments, physician interviews, and automated chart reviews. The hierarchical structure was taken from SNOMED-CT. We could not simply use SNOMED-CT because it is too exhaustive to be useful. We add entities where necessary to remain true to our data.
Drug-Induce Liver Injury (combined): A SNOMED subset of terms related to histological and clinical descriptions of Drug Induced Liver Injury (DILI). See Wang et al., "A Unifying Ontology to Integrate Histological and Clinical Observations for Drug-Induce Liver Injury" The American Journal of Pathology, 182:4,1180-1187 (2013). This view contains both of the DILIo major branches; SNOMED:Body Structure and SNOMED:Clinical finding Some of the class names have been changed to correspond to the preferred names in SNOMED of 7/31/2011. In DILIo publication -> in this file; Disorder of liver -> Disease of liver; Finding of general form of body -> General form of body - finding; Finding of size of liver -> size of liver - finding; Subacute necrosis of liver -> subacute hepatic necrosis
Maternity_Test_Case2: Testing
MEdical LifeLog Ontology for people with disability: No description provided
SNOMED CT Standard Ontology Based on the Ontology for General Medical Science: The Systematized Nomenclature of Medicine Clinical Term Ontology (SCTO) attempts to create a basic OWL 2 ontology for SNOMED CT terminology. The ontology is built based on the Ontology of General Medical Science (OGMS). This ontology implements the SNOMED CT concept model by adding the appropriate axioms to its top-level concepts. The resulting ontology can prevent redundancies and inconsistencies in this large terminology. Moreover, the terminology maintenance can become more accurate. Finally, SNOMED CT can be used in a healthcare environment to create more complex post-coordinated expressions and constraints in a more accurate manner.
SNOMED Terminos Clinicos: SNOMED Terminos Clinicos (SNOMED CT), Edicion en Espanol, Distribucion Internacional, Octubre de 2008, 2009_04_30
Neoplasm_hamartoma: subset of snomed-ct regarding neoplasm and hamartoma
Neoplasm_breast_cancer: This a subset of Neoplasm_hamartoma view, based on Snomed clinical practice's used terms (Fondazione S.Maugeri anatomic pathology dep.). This subset is not to be meant exhaustive, it has been created in order to built a proper ontology for our project, ONCO-i2b2, through the NCBO Ontology Tools.
Snomed neoplasm, breast cancer: This a subset of snomed-ct regarding neoplasm and hamartoma, based on Snomed clinical practice's used terms (Fondazione S.Maugeri anatomic pathology dep.). This subset is not to be meant exhaustive, it has been created in order to built a proper ontology for our project, ONCO-i2b2, through the NCBO Ontology Tools.
Snomed, Body Structure: The Body Structure subtree in SNOMED-CT. It has been created in order to built a proper ontology for our project, ONCO-i2b2, through the NCBO Ontology Tools.
SNOMED Ethnic Group: Ethnic Group From SNOMED CT
SNOMED Anatomy: The Anatomy class subtree in SNOMED-CT based on SNOMED CT 2009.07.31
SNOMED Clinical Finding: Extract from SNOMED
SNOMED Organism: The Organism subtree in SNOMED-CT based on SNOMED-CT v. 2009.01.31
SNOMED Test Findings: The Test Findings subtree in SNOMED-CT based on SNOMED-CT v. 2009.01.31
SNOMED Morphologically Abnormal Structure: The Morphologically Abnormal Structure subtree of SNOMED CT
Reserved Acronym SNOMEDCT_US: Reserved acronym to prevent URI collusion with SNOMEDCT. see https://github.com/ncbo/bioportal-project/issues/198

Classes	382,297
Individuals	0
Properties	246
Maximum depth	30
Maximum number of children	3,026
Average number of children	4
Classes with a single child	49,811
Classes with more than 25 children	3,201
Classes with no definition	373,241