The Consumer Real-time Pharmacy Benefit Check (RTPBC) IG client system is a mobile consumer application, which will typically not know the telephone number of the user. The US Core Patient profile sets Patient.telecom elements as Must Support, which presents an obstacle to using the US Core Patient in the Consumer RTPBC IG.

The proposed RTPBC Patient profile below does not set the Patient.telecom elements as Must Support, because they will typically not be known with certainty by the IG's participants and the information is not pertinent to the IG's use case.

http://build.fhir.org/ig/HL7/carin-rtpbc/StructureDefinition-rtpbc-patient.html