This article describes a 4-year study of experienced high school biology teachers' participation in a five-step professional development experience in which they iteratively studied student ideas with the support of a set of learning progressions, designed formative assessment activities, practiced using those activities with their students, enacted the activities, and then reflected on next steps to guide their instruction. Drawing on classroom artifacts and student responses to a pre-post assessment, we examined the alignment of teacher-created formative assessment tasks with the learning progressions, as well as student learning relative to the progressions. A partial-credit Model revealed that the majority of students' learning reflected learning from lower- to upper-anchors on multiple learning progressions. This finding suggests that, by participating in the professional learning experience, teachers were able to successfully support student learning of the content as represented in the majority of the learning progressions. Results are interpreted in light of learning progressions being used as scaffolds for formative assessment design and practice.