Unfortunately, at this time, Organization is not a supported resource for DSTU2. You can see all of our currently available functionally by visiting
fhir.cerner.com. The current method of getting organization information is to get a an export of all of Organizations upon onboarding of your application into a clients domain and the app performing a cross reference to with the exported Organizations to get the information needed. There is no FHIR resource at this time for communication between a patient and a practitioner.