Abstract: A health care transaction processing system for facilitating information exchange between a health care provider and a plurality of payors is described herein. The system comprises a health care provider computer configured to generate transaction data of a first predefined format. A transaction processing platform, operatively connected to the health care provider computer, serves to (i) convert the transaction data from the first predefined format into a first document formatted consistently with one of a plurality of common data type definitions (DTDs) corresponding to a set of standardized health care transactions, and (ii) translate the first document into a first transaction request document formatted consistently with a second predefined format. The system further includes a first payor computer operatively connected to the transaction processing platform.