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Data stored in an (EHR) that includes SNOMED CT or may also include a human readable term associated with each concept identifier. In this case, EHR data can be displayed without using any terminology services. However, as shown in there are several situations in which it may be necessary to lookup and display a term rather than relying upon a term stored in the record.

Reasons for Looking Up Terms when Displaying EHR Data

Reason	Notes
To display the preferred term or fully specified name of a concept in the following situations:
If a record entry contains a concept identifier without an associated term	It is good practice to store the selected term as well as the concept identifier but this is not mandatory.
If a communication contains a concept identifier without an associated term	It is good practice to communicate the selected term as well as the concept identifier but this is not mandatory. In some cases, the design of a message or interchange format may not support the inclusion of terms for all concept identifiers. This may be a particular issue when postcoordinated expressions are communicated as some interchange formats may not support the inclusion of terms for each concept identifier in an expression.
If the synonym in a record entry or communication is ambiguous	The term stored or communicated may be appropriate to the concept but may not be sufficiently clear. For example, the term "fundus" is a valid synonym for four different concepts. Looking up the for the concept identifier allows the display of term that removes this ambiguity.
To display the preferred term for a concept in a familiar language: If the term stored or communicated is in an unfamiliar language	The term stored or communicated may be in a language that the user does not understand. If the concept is also included in the edition used by the viewer, it should be possible to display the term in the viewers own language.
To confirm that a term linked to a concept identifier is a valid: If there is a requirement for quality assurance validation	Even when a term is stored or communicated with a concept identifier, it may be useful to confirm that the term included is associated with that concept identifier.

shows a summary of the services required to support display of EHR data including looked up terms.

Services Required to Enable Display of EHR Data

Practical Requirement	Status	Required Terminology Services	Additional Terminology Service Dependencies
Enable the selection of SNOMED CT edition and version to be used		4.1 Select Edition and Version	N/A
Display terms for the concepts in EHR record entries and communications		4.3 Get Terms for a Concept	N/A

Term lookup will fail if the concept is a that is not included in the viewers edition.
Term validation will fail if the term is in a in a that is not included in the viewers edition (for example the term may be part of a module including term in a language not used by the viewer.
Applications designed to address this use case must support the practical requirements marked as Required. Support for the practical requirements marked as Optional is recommended as these provide enhanced functionality that may be required by some users.
In most cases, a reference to a subsection of 4 Terminology Service Types, implies a requirement for all services marked as Required in that subsection. However, where a reference is followed by a bulleted list, that list specifies the specific terminology services required. Some of the specific services listed as required for an Optional practical requirement may be marked as Recommended in the referenced subsection.
The Additional Terminology Service Dependencies column contains references to services on which a Required Terminology Service depends. This column does not restate dependencies on services listed as required service or additional dependencies for essential requirements listed in earlier rows. A full list of the dependencies of each terminology service is provided in the relevant subsection of 4 Terminology Service Types.