Can I identify the referring physician for an inpatient stay using the Inpatient claims?

Not reliably: The Inpatient claims have changed format and content over the past 4 years. The current Inpatient claims data contain the field called "Attending UPIN". The current definition for this field requires the provider (hospital) to report the following: The unique identification physician number (UPIN) of the physician who would normally be expected to certify and re-certify the medical necessity of the services rendered and/or who has primary responsibility for the beneficiary's care and treatment. This may or may not be the "Referring Physician". This data field is not stored in the MedPAR.  more