This study investigates relationships between teachers' receipt of high-stakes test score results of their students and subsequent changes in instructional and classroom assessment practices the following year. The sample consisted of 722 elementary, middle, and high school teachers. The results indicate that most teachers reported using the results to make instructional and assessment changes, especially those who emphasized depth of learning and higher-level cognition. Greater collaboration among teachers was reported, as well as more formative classroom assessment. Elementary teachers changed more than secondary teachers. Small to moderate effect sizes suggest important impacts on a moderate number of teachers that are more positive than previously reported for high-stakes minimum competency testing. (Contains 5 tables.)