The business case here does not allow query of the information needed to be retrieved. The request results in a human assembling data into a document.  There is no way one payer will allow another payer to query and go digging through data on the patient via query.  The source payer will specifically decide on what information is necessary to deliver continuity of care, will filter data if needed, and package it in a way that provides context. At least for now, this will be an asynchronous process. If it gets to the point where it can be automated for certain types of patients/conditions/care, it will still be a patient-specific operation and not a standard query.  In short, RESTful query can't produce what we're looking for.