The following historical review of the federal and state policies surrounding early childhood assessment illuminates gradual shifts in how accountability and school readiness have been construed. While government has always demanded accountability from funded programs, such accountability has historically been an audit-like accountability that involved counting the number participants and calculating the budget spent. With the introduction of No Child Left Behind Act of 2001 (U.S. Department of Education, 2001), the focus shifted to learning-related outcomes. With this new results-based accountability, programs are held accountable for making an impact on learning outcomes for all children, not just pursuing the goal of serving children families (Horsch, 1996). Consequently, questions about how to define school readiness and how to effectively assess children for school readiness are now at the forefront of educational and political discussions. The goal of this chapter is not to provide consensus on what school readiness may be, but rather to briefly document ways that school readiness has been conceptualized and assessed at the federal and state levels, and to provide a critical analysis of the issues surrounding the assessment of young children. (author abstract)