Learning progressions--particularly as defined and operationalized in science education--have significant potential to inform teachers' formative assessment practices. In this overview article, I lay out an argument for this potential, starting from definitions for "formative assessment practices" and "learning progressions" (both in science education and more subject-general literature). By aligning the challenges that teachers face in enacting formative assessment practices with the affordances of learning progressions, I explain how learning progressions may support these practices. Finally, I preview how the articles in the special issue address this hypothesis.