Previous research has consistently cited the importance of a usable interface in the successful adoption of the electronic health record (EHR). Among the most time intensive EHR activities is Computerized Physician Order Entry (CPOE) a method of creating and modifying orders through an electronic interface. The Marshfield Clinic, a non-profit, regional health care organization in Wisconsin, is in the process of implementing a new CPOE system. As a part of early evaluation, cognitive and behavioral modeling was coupled with formative usability testing to better understand the potential use of a new CPOE design. Participants consisted of 11 medical residents. Results suggest that participants were able to complete the majority of task scenarios in less than 20 seconds per task. Additionally, the integration of a cognitive and behavioral tool provided new evaluation information to help aid in future design efforts.