Recent federal investments in early childhood assessment systems are the result of a national need for developmentally appropriate, psychometrically sound instruments to monitor young children and evaluate the effectiveness of their learning programs. In this paper, we examined the association between teachers' perceptions of their students at the start of kindergarten and academic achievement in Grade 3 with hierarchical linear modeling using state-level data from nearly 30,000 students. The analyses showed that such an association exists even after accounting for student-level and school-level demographic variables and is moderated by the percentage of free-lunch-eligible students in a given school. Implications of these findings related screening and assessment at kindergarten entry are discussed. (author abstract)