This chapter explores the challenges and implications of designing authentic assessments for accountability purposes. Educational accountability takes many forms, from student-level certification for high school graduation to district-level accreditation to ensure that students are being provided with appropriate learning opportunities. Accountability systems are designed to instantiate policy values to lead to certain ends (e.g., 100 percent of students proficient in reading and math). Essentially all accountability systems involve collecting data, analyzing those data according to specific rules to transform the data into accountability indicators, classifying the indicators into various levels of performance (e.g., exemplary to failing), and attributing the results to appropriate individuals or organizations. Many current educational accountability systems have stated goals of promoting deeper learning for students for a variety of reasons, including, among other goals, improving college and career readiness. This chapter takes the position that performance-based and -related assessment approaches must be meaningfully incorporated into accountability systems-by serving as at least one key source of “input” data-if we are to do more than pay lip service to these policy goals. This chapter focuses on design considerations for performance-based assessments for use in accountability systems. This is a broad topic. In order to provide more than a superficial discussion, we focus much of the chapter on the use of performance-based assessments in educator evaluation systems, although the chapter includes brief discussions of school and student accountability systems as well. We do not focus on combining the results of performance-based or other open-response tasks with more traditional selected-response items into a single assessment score for use in any of these accountability determinations. This is clearly an important issue, but beyond the scope of this chapter.