Ongoing improvements in the content of the Unified Medical Language System, coupled with the recent release of the Internet-based Knowledge Source Server (KSS), have prompted us to develop an interface between the KSS and our computer-based patient record. We confronted many challenges while developing a robust interface to an Internet-based server, and in integrating the process of codification into the workflow of clinicians. An initial evaluation of the interface in the clinical environment suggests that acceptable performance is attainable. The benefits of using an Internet-accessible tool in a clinical information system appear to justify the effort required.