Background and Context: To better reflect the computational nature of STEM disciplines and deepen learning of science content computational thinking (CT) should be integrated in science curricula. Teachers have a critical role in supporting effective student learning with CT integrated curricula in classroom settings. Objective: Our team worked with high school teachers to co-design and implement CT-integrated biology units. Method: We use a model of professional growth and qualitative case studies to characterize changes in teacher practice and values through their involvement in co-design and implementation of a CT-integrated biology unit. Findings: Teachers followed similar pathways of professional growth, but their participation and perceptions varied, resulting in three dimensions: 1) participation during design, 2) participation in co-design during implementation, and 3) perception of CT benefits related to student learning. Implications: It is important to support teacher comfort and engagement in the co-design process in order to better facilitate professional growth and CT integration.