In this study, we describe a systematic approach to designing rubrics for scoring equitable physical science assessment items as part of our design process . The assessment items measure student proficiency based on learning performances that integrate disciplinary core ideas (DCI), crosscutting concepts (CCC), and scientific practices. Focal knowledge, skills, and abilities (FKSAs) guided the design of these rubrics. The use of FKSAs allows for a systematic way of assessing students’ knowledge-in-use. Items for chemical reactions and energy at the middle school grade band have been implemented in various classroom environments. Teachers from several school districts used items in a variety of ways, resulting in approximately 108 to 174 scored responses for each item. The results from scored student responses will help inform and modify teacher instruction, facilitating “next steps” that will result in effective future student instruction.