This study investigates students’ conceptions of engineering at the beginning and end of their involvement in a National Science Foundation funded Graduate STEM Fellows in K-12 Education (GK-12) program. It examines whether students involved in the program exhibited greater conceptions of engineering from beginning to end, whether differences exist among males and females, and if students’ engagement and satisfaction with their Fellows affects growth in conceptions of engineering. Pre-survey and post-survey data were collected annually over four years from 1,522 participants in grades 7 and 8 who had a GK-12 Fellow. Statistical analyses indicated students gained significantly in their conceptions of engineering during a year of GK-12 involvement. Those with a second year benefitted more, and the initial conception of engineering gap that occurred between males and females was closed by the end of students’ involvement in GK-12. The greater the degree of student engagement and satisfaction with their GK-12 Fellows, the more accurate were their conceptions of engineering. This study suggests STEM-focused partnership programs may positively affect students’ career conceptions, and there is value in value placing resident scientists who can facilitate student engagement in classrooms. Recommendations to program coordinators are provided.