Abstract: In this study, we explore the effectiveness of a professional development model that aims to build teacher capacities for k-12 schools. Specifically, the study is guided by these questions: 1). Does the PD improve teachers’ understanding of computational thinking aligned with Common Core State Standards (CCSS) & Next Generation Science Standards (NGSS) in STEM areas?2). What are lessons learned when implementing this professional development model? A mixed methods research approach was adopted. Participants were 25 practicing teachers in k-12 classrooms. The results show that the PD enhanced teachers' understanding of CT. In addition, the full paper discusses the affordance of the model and challenges identified during the implementation process.