Since 2004 the National Science Foundation has supported a rigorous research and policy study incorporating Mathematics Specialist preparation programs and randomly selected treatment and control elementary (K-5) schools (NSF grants ESI-0353360 and EHR-0412324). Grant-supported trained specialists were placed in the treatment schools as on-site coaches to determine the effectiveness of a school-based Mathematics Specialists program. Grant findings are that Mathematics Specialists over time help classroom teachers develop more effective teaching practices that positively affect student learning and achievement.