A 900000000000496009 | Simple map from SNOMED CT reference set|  supports the representation of simple maps from SNOMED CT concepts to values in other code systems. No constraints are put on the number of coding schemes supported, the number of codes within a particular scheme mapped to by a single SNOMED CT concept or the number of SNOMED CT concepts mapping to a particular code. However, this type of reference set is usually only appropriate where there is a close "one-to-one" mapping between SNOMED CT concepts and coded values in another code system.

Data structure

A 900000000000496009 | Simple map from SNOMED CT reference set|  is a String reference set used to represent maps from SNOMED CT concepts to codes in another terminology, classification or code system. Its structure is shown in the following table.

Table Simple map from SNOMED CT reference set - Data structure


Data type


Part of Primary Key


A 128 bit unsigned Integer, uniquely identifying this reference set member.

Different versions of a reference set member share the same id but have different effectiveTime. This allows a reference set member to be modified or made inactive (i.e. removed from the active set) at a specified time.

NOYES (Full /Snapshot)

The inclusive date or time at which this version of the identified reference set member became the current version.

Note: In distribution files the effectiveTime should follow the short ISO date format (YYYYMMDD) and should not include the hours, minutes, seconds or timezone indicator.

The current version of this reference set member at time T is the version with the most recent effectiveTime prior to or equal to time T .


YES (Full)

Optional (Snapshot) 

The state of the identified reference set member as at the specified effectiveTime .

If active = 1 (true) the reference set member is part of the current version of the set, if active = 0 (false) the reference set member is not part of the current version of the set.


Identifies the SNOMED CT module that contains this reference set member as at the specified effectiveTime .

The value must be a subtype of 900000000000443000 | Module (core metadata concept)| within the metadata hierarchy.


Identifies the reference set to which this reference set member belongs.


A reference to the SNOMED CT component to be included in the reference set.

Refers to the SNOMED CT concept from which the mapTarget is mapped (i.e. the map source).


The equivalent code in the other terminology, classification or code system, to which the referencedComponentId is mapped.



The following metadata hierarchy supports this reference set:

Table Simple Map from SNOMED CT Reference Sets in the Metadata Hierarchy

Reference Set Descriptor and Example Data

Notes on the tables used to show descriptors and examples

The reference set example tables on this page have been revised as follows to aid clarity and understanding:

  • The first four columns which are present in all release files are not shown. The omitted columns (ideffectiveTimeactivemoduleId) are used in the same way in all referenced sets to support identification, versioning and packaging. They do not directly affect the specific features of a particular reference set or reference set type.
  • Reference set columns that contain SNOMED CT identifiers are expanded to show details of the concept or description referenced by that identifier. In some cases, the term is shown in the same column using the expression syntax, in other cases an additional column with a name suffix '_term' has been added. In the standard reference set files only the identifier is present in the column and there is no added column for the term. When using reference sets, the term and other details of the component are looked up from the relevant component release files.

Descriptor template and examples

The tables below show the descriptors that define examples of reference sets that follow the 900000000000496009 | Simple map from SNOMED CT reference set| pattern.

Table Refset Descriptor rows

Refset Examples

Table Sample Content from a Simple Map From SNOMED CT Reference Set

  • No labels