While gifted students are often treated as a homogenous group in gifted and talented programs, they are indeed a diverse group. Because of this diversity, differentiation is essential, but often not practiced in gifted classrooms. Differentiation’s component of formative assessment is a crucial step for informing instruction to meet diverse needs. This session examines the use of formative assessment in two reading units, as well as teacher perceptions of its benefits and limitations. Strategies to create and respond to formative assessment data are explored to identify key components that can be used to benefit both teacher and student.