With the call for increasing the level of inquiry-based instruction in mathematics and science classrooms, it is imperative for teacher education programs to prepare teachers with these skills. This study draws from classroom observation data to determine the influence a unique teacher certification program has on key aspects of teacher practice using a series of Kruskal-Wallis and Wilcoxon Rank Sum tests. Findings indicate that teachers participating in the program have a statistically significant level of growth in their use of inquiry practices related to Classroom Culture. In addition, by the fourth semester of their involvement in the program, participating teachers employ higher levels of inquiry instruction than a comparison group of teachers for almost every factor assessed.