Over the course of developing Consolidated State Plans, states have spent time evaluating their accountability systems. Many of the accountability requirements of the No Child Left Behind Act of 2001, such as the inclusion of academic measures of students' proficiency on annual assessments, graduation rates, and English learners' progress toward attaining English proficiency, are maintained under the "Every Student Succeeds Act" (ESSA). As a new requirement, states must adopt at least one additional indicator of school quality or student success in addition to other required accountability indicators. While this indicator should not be given significant weight, it does play an important role in accountability systems to signal what the state considers important in school performance (ESSA, section 1111(c)(4)(C)). Many states already include one or more indicators (e.g., dropout rate, student attendance, credit accumulation, Advanced Placement [AP] and International Baccalaureate [IB] participation and performance, and dual enrollment [where students enroll in postsecondary coursework while also enrolled in high school]) in their accountability systems and may not need to make revisions based on this requirement. However, some states are considering adding or modifying indicators in this category under ESSA requirements. The purpose of this report is to analyze the key factors that states will need or want to consider in determining which school quality or student success measures to include in their accountability systems. There are numerous factors to consider, including, but not limited to, stakeholder feedback, available research, cost of implementation, and ability to disaggregate by student population. Design and implementation considerations are discussed in the subsequent sections of this report. Finally, it is important to note that some of the measures examined in this report may not be ready for inclusion in the formal school accountability system (due to challenges related to data collection, cost, validity, etc.), but they may still be worthwhile to report publicly to parents and educators to provide additional data and information about schools. These measures may evolve to be formal accountability measures over time, or may remain important data points to share but not include in accountability systems.