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Clinical information recorded using SNOMED CT may include data that is relevant to reports, statistical returns, billing claims, etc. that need to be encoded using a specific code system or a statistical classification such as ICD-10. Mapping allows relevant information to be used for those purposes, minimizing the requirement for additional manual data entry.
Organizations planning to implement SNOMED CT based solutions may also be faced with data transformation and migration challenges which lead them to consider mapping their existing clinical data, code systems or classifications to SNOMED CT.
As a common global reference terminology, SNOMED CT limits the need for development of "everything to everything" maps between multiple different code systems.

What is this?

Maps are associations between particular codes, concepts or terms in one code system and codes, concepts or terms in another code system that have the same (or similar) meanings. Mapping is the process of defining a set of maps. Maps are developed in accordance with a documented rationale, for a given purpose and as a result there may be different maps between the same pair of code systems to meet different uses cases.
There are a number of different types of mapping activities that an Organisation may need to undertake. These include mapping:

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