Federal law requires states to develop systems to hold K-12 schools accountable for the outcomes of all students. This includes using data to illuminate how historically marginalized groups of students, including English Learners (ELs), are disadvantaged by systems that fail to meet their distinct needs. But for this to be useful for school improvement, policymakers, educators, and community members need to trust that the data accurately identify successes, challenges, and inequities in educational opportunities provided to students. A key challenge is that ELs, unlike their non-EL peers, are expected to learn and master academic content while also learning and becoming proficient in English. Yet, the impact of ELs' development of English language proficiency is often not taken into account when reporting and interpreting EL outcome data in academic subjects. In addition, there have been calls to integrate more information about the nature and quality of the language services ELs receive at school into accountability systems in order to make the impact of school system resources, contexts, and practices more transparent--something existing accountability systems rarely do in a comprehensive, meaningful way. This report presents the findings of two studies, one quantitative and one qualitative, focused on state accountability systems and ELs. The overall project's aim is to rethink accountability with an eye to (1) addressing problems with the validity of summative assessment outcomes for ELs and (2) incorporating students' opportunities to learn and program quality into an accountability system whose value is being questioned in many communities.