This article presents findings about the implementation of a system for rapidly assessing student progress in math and reading in grades K–12—a system that potentially could reduce pressure on teachers resulting from high-stakes testing and the implementation of the No Child Left Behind Act. Interviews with 49 teachers and administrators in one Texas school district suggest that the assessments allowed teachers to individualize and target instruction; provide more tutoring; reduce drill and practice; and improve student readiness for, and spend more time on, critical thinking activities, resulting in a more balanced curriculum. Teachers reported that the assessments provided a common point for discussion, increased collaboration among teachers to improve instruction and resolve instructional problems, and supported both new and experienced teachers in implementing sound teaching practices. The individualized curriculum and rapid feedback on progress reportedly gave students the feeling that they were successful and in control of their own learning, engaging students who previously disliked reading and math—including dyslexic children and children in special education—reducing stress, and improving student achievement. These findings are interpreted through Corbett and Wilson’s framework for understanding why high-stakes testing often has negative effects and why the implementation of rapid assessment systems could reduce unintended negative consequences of testing.