One model of engineering integration that has shown promise is the use of engineering design as a context to support teachers as they conceptualize and plan integrated STEM lessons. However, integrating engineering into science instruction presents a number of challenges, especially at the elementary level, and the implementation of high-quality engineering design-based instruction is not often what is actualized in the classroom. This study investigated how teachers operationalized an engineering design-based lesson in their classroom by examining what elements of engineering teachers chose to include within in their lesson plan and enact in the classroom. Participants included 20 triads composed of teachers, student teachers, and engineering graduate students. Utilizing a multiple case study approach, this study found that there were four main groupings related to how teachers operationalized engineering design-based instruction in their classrooms. Results suggest that even though there were several engineering design elements that were included in a majority of the lesson plans, such as context, constraints, materials exploration, and building, and testing solutions, some characteristics were found to be more influential than others when looking at how to help teachers to implement high-quality engineering design-based instruction.