Abstract: A system and method for determining an updated disease classification code for a patient within a managed care population consisting of (i) a patient condition processing unit for receiving a plurality of patient-related data, (ii) a diagnosis repository database coupled to the patient condition processing unit for storing a preestablished disease classification code for the patient, and (iii) a disease classification code application tool designed to convert medical chart data of the patient into an observed disease classification code for the patient wherein the observed disease classification code is forwarded to the patient condition processing unit and stored in a diagnosis repository database as the updated disease classification code. The updated disease classification code can then be forwarded to the treating physician, reimbursement agency, or any other agency requiring such data.