Abstract: A case management system has a central data store (4) comprising at least one data storage unit. An injury classification code database (4A), treatment database (4B), and diagnosis database (4C) are maintained thereon. A processor (8) in operative communication with the data store (4) and the Internet (2) performs the steps of: creating (14) a claim file on the data store (4); receiving information (12, 22, 36, 86, 88, 102, 304) about the claim via the Internet (2); storing (16, 52, 308) the received information in the claim file; establishing a diagnosis (32, 34, 36); creating a treatment plan (50) based on the diagnosis using the treatment database (4B); and transmitting (82, 84, 90, 301, 302) information from the claim file via the Internet (2) upon receipt of valid security information. Establishing a diagnosis (32, 34, 36) optionally includes receiving responses (22) to an Internet questionnaire and determining a suggested diagnosis by comparing with the diagnosis database (32).