Classroom teachers are among the few remaining employee groups whose evaluations and remuneration are generally unrelated to their performance. However, it is difficult to appraise a teacher's effectiveness by achievement of pupils because learning is not under an instructor's complete influence. New measurement techniques are emerging, however, that offer a prospect of discerning how much an individual teacher's instructional efforts contribute to learning. This article identifies impediments to implementing "value-added" testing, recommends a development effort to address unresolved issues, and specifies components of a proposed Education Professions Performance Development Act that could direct federal resources. These recommendations include alterations to No Child Left Behind Act regulations to further a fair and accurate teacher assessment and reward system based on performance.