This groundbreaking study is the first ever to examine the achievement of high-performing students over time "at the individual level". It poses--and seeks to answer--this straightforward question: Do students who outscore their peers on standardized achievement tests remain at the top of the pack year after year? Put differently, how many "high flyers" maintain their "altitude" over time? How many fall back toward Earth as they make their way through school, losing the academic edge they once enjoyed? Findings include: (1) A majority of high flyers maintained their status over time, but substantial numbers "lost altitude"; (2) Most Descenders don't fall far; and (3) High flyers grew academically at similar rates to low and middle achievers in math, but grew at slightly slower rates than low and middle achievers in reading. Appended are: (1) Methodology; and (2) Methodology Specific to "A Closer Look at High Flyers in High-Poverty Schools." (Contains 9 tables, 7 figures and 14 footnotes.) [Foreword by Chester E. Finn, Jr., Amber M. Winkler, and Janie Scull.]