This chapter explains an overview of the multifaceted context for arts assessment in the United States. It lays out the challenges to arts assessment, followed by a brief review of the status of arts assessment in music, dance, theater, and the visual arts. The chapter then discusses selected states’ arts assessment systems and the emerging national system of Model Cornerstone Assessments (MCAs). When arts assessment data have been shared outside the classroom, the purpose has typically been to advocate for programs by demonstrating to parents and policymakers that students have attained high levels of achievement in competitive or adjudicated settings such as large ensemble festivals, thespian events, or art contests. The chapter reviews the evolution of the measurement of arts learning, describes key challenges in the current age of accountability, and identifies promising strategies that have emerged to address those challenges.