This document provides an executive summary of "Reading First Impact Study. Final Report. NCEE 2009-4038." The final report presents findings from the third and final year of the Reading First Impact Study (RFIS), a congressionally mandated evaluation of the federal government's initiative to help all children read at or above grade level by the end of third grade. The No Child Left Behind Act of 2001 (NCLB) established Reading First (RF) and mandated its evaluation. This report examines the impact of Reading First funding on 248 schools in 13 states and includes 17 school districts and one statewide program for a total of 18 sites. The study includes data from three school years: 2004-05, 2005-06 and 2006-07. Key findings include: (1) Reading First produced a positive and statistically significant impact on amount of instructional time spent on the five essential components of reading instruction promoted by the program (phonemic awareness, phonics, vocabulary, fluency, and comprehension) in grades one and two; (2) Reading First produced positive and statistically significant impacts on multiple practices that are promoted by the program, including professional development in scientifically based reading instruction (SBRI), support from full-time reading coaches, amount of reading instruction, and supports available for struggling readers; (3) Reading First did not produce a statistically significant impact on student reading comprehension test scores in grades one, two or three; and (4) Reading First produced a positive and statistically significant impact on decoding among first grade students tested in one school year (spring 2007). Findings are generally consistent with findings presented in the study's Interim Report. Although the study finds, on average, that after several years of funding, the Reading First program has a consistent positive effect on reading instruction yet no statistically significant impact on student reading comprehension, findings based on exploratory analyses do not provide consistent or systematic insight into the pattern of observed impacts. (Contains 6 footnotes and 5 exhibits.) [For the interim summary of this study, see ED501219. For full interim report, see ED501218. For the final report, see ED503344.]