Coverage.Subscriber Type is Reference([C4BB Patient|http://build.fhir.org/ig/HL7/carin-bb/branches/v1.1.0/StructureDefinition-C4BB-Patient.html]).  The decision was to provide the Subscriber Id in Coverage.subscriberID.  Revert Coverage.Subscriber Type to that defined by the base Resource, Reference([Patient|https://www.hl7.org/fhir/patient.html] | RelatedPerson).    Coverage.Subscriber is not a CPCDS data element nor is it Must Support