Others titles

  • SNOMED CT United States Edition
  • SNOMED CT Latest Version
  • Machine Readable Concept Model of SNOMED CT


  • Clinical Terminology
  • Systematized Nomenclature of Medicine Clinical Terms
  • Healthcare Terminology
  • Electronic Health Records
  • Machine Readable Concept Model

SNOMED CT Snapshot Extended Map Reference Set

Complex and Extended map type reference set enables representation of maps where each concept may map to one or more codes in a target scheme. It also supports the general set of mapping data required to enable a target code to be selected at run-time from a number of alternate codes. It supports target code selection by accommodating the inclusion of machine readable rules and/or human readable advice. Extended map type reference set adds an additional field to allow categorization of maps.

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SNOMED CT (SNOMED Clinical Terminology) provides a common language that assists with the electronic exchange of clinical health information. It enables a consistent way of indexing, storing, retrieving, and aggregating clinical data across specialties and sites of care. SNOMED CT Can be mapped to other coding systems, such as ICD-10, which helps facilitate semantic interoperability.

A Snapshot release contains the most recent version of every component released up to the time of the snapshot. The version of each component contained in a snapshot is the most recent version of that component at the release time. The ‘Snapshot’ release is useful for a simple installation but does not provide a history or retrospective view of the terminology. There are valid use cases for each Release Type. Each International release will incorporate all three of these Release Types, allowing users to choose the most appropriate format.

In addition to 623 new concepts specific for the US, the September 2018 SNOMED CT US Edition also contains all of the content from the July 2018 SNOMED CT International Edition. Approximately 543 requests for terminology additions and updates were submitted via the US Content Request System (US CRS) to support US clinical health information data exchange. This latest version of the US Edition also includes the SNOMED CT to ICD-10-CM reference set, with over 123,000 SNOMED CT source concepts mapped to ICD-10-CM targets.

About this Dataset

Data Info

Date Created


Last Modified




Update Frequency


Temporal Coverage


Spatial Coverage

United States


John Snow Labs; International Health Terminology Standards Development Organisation (IHTSDO), U.S. National Library of Medicine (NLM);

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Clinical Terminology, SNOMED CT, IHTSDO, Systematized Nomenclature of Medicine Clinical Terms, Healthcare Terminology, Electronic Health Records, Machine Readable Concept Model

Other Titles

SNOMED CT United States Edition, SNOMED CT Latest Version, Machine Readable Concept Model of SNOMED CT

Data Fields

Name Description Type Constraints
Reference_Set_Member_IdA field, uniquely identifying this reference set member. Different versions of a reference set member share the same ID but have different Effective_Date. This allows a reference set member to be modified or made inactive (i.e. removed from the active set) at a specified time.stringrequired : 1
Effective_DateThe inclusive date at which this version of the identified reference set member became the current version.daterequired : 1
Is_ActiveThe state of the identified reference set member as at the specified Effective_Date. If active= true, the reference set member is part of the current version of the set, if active=false, the reference set member is not part of the current version of the set.booleanrequired : 1
Module_IdIdentifies the SNOMED CT module that contains this reference set member as at the specified Effective_Date.integerrequired : 1level : Nominal
Refset_IdIdentifies the reference set to which this reference set member belongs.integerrequired : 1level : Nominal
Referenced_Component_IdA reference to the SNOMED CT concept being mapped.integerrequired : 1level : Nominal
Map_GroupAn integer, grouping a set of complex map records from which one may be selected as a target code. Where a SNOMED CT concept maps onto 'n' target codes, there will be 'n' groups, each containing one or more complex map records.integerrequired : 1level : Ordinal
Map_PriorityWithin a Map_Group, the Map_Priority specifies the order in which complex map records should be checked. Only the first map record meeting the run - time selection criteria will be taken as the target code within the group of alternate codes.integerrequired : 1level : NOrdinal
Map_RuleA machine-readable rule, (evaluating to either 'true' or 'false' at run-time) that indicates whether this map record should be selected within its map group.stringrequired : 1
Map_AdviceHuman-readable advice, that may be employed by the software vendor to give an end-user advice on selection of the appropriate target code from the alternatives presented to him within the group.stringrequired : 1
Map_TargetThe target code in the target terminology, classification or code system.string-
Correlation_IdIdentifyies the correlation between the SNOMED CT concept and the target code.integerrequired : 1level : Nominal
Map_Category_IdIdentifies the SNOMED CT concept in the metadata hierarchy which represents the Map Category for the associated map member. The categories vary for different target code systemsintegerrequired : 1level : Nominal

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