All CIMs implicitly contain a number of basic concepts, such as an identification number or a reference to the patient the data belongs to. These are usually not included in the information models of the individual CIMs, but are supposed to be present. These are concepts that are of a more technical nature, sometimes have little or no clinical relevance, but are necessary for the sake of clarity and readability of the information. These basic concepts are collected in this Base model.

Whenever similar concepts are in fact of clinical significance in the context of a certain CIM, they will be explicitly added in the information model of that CIM. An example of this is the inclusion of a healthcare provider reference to convey the relevant location in a CIM like Encounter or Procedure (next to the HealthcareProvider concept (medmij-core-dataelement-117) already present in this Base model), since the location where an encounter took place or where a procedure was carried out might be of clinical significance. Moreover, identification numbers with clinical significance such as AGB or UZI, might be added explicitly in certain CIMs (next to the IdentificationNumber concept (medmij-core-dataelement-115) already present in this Base model).