Abstract: A system and method for rationalizing physician data in which source data is collected from source computers located at, for example, physicians' offices, hospitals, testing laboratories and pharmacies. Source data is expected to be in diverse formats and syntax, according to the particular hardware/software/operating system configuration of the source computer. Source data is converted to a common format, advantageously ASCII text, and is parsed and binned into a standard data element "layout." Source data is then cross-referenced and cleaned against standard data resources such as Medicare UPIN tables and AMA ICD9 tables. In this way, analogous data elements acquire a common alphanumeric syntax. Keying errors may also be corrected and missing information may be supplied. Source data is then ready to be accumulated into a standard database of universal format.