Reducing redundant medical lab tests has been discussed in the literature as a cost saving benefit of Electronic Health Record (EHR) adoption; however the literature does not provide a great deal of information on the mechanics of achieving this goal. Laboratory ordering using an EHR occurs within a complex socio-technical context that can be difficult to understand. A case study was performed on an EHR that provided insight into the interplay of these elements as well as the current state of laboratory ordering guidelines. A theoretical framework, using Strong Structuration Theory was used to guide the research. The result was improved insight into required technological capabilities to support clinical care and the environmental contexts that shape them.