The School Improvement Grant (SIG) program funds reforms in low performing schools. Congress provided $3.5 billion for SIG in fiscal year 2009, and a total of about $1.6 billion was appropriated in fiscal years 2010-2012. SIG requirements changed significantly in 2010. Many schools receiving SIG funds must now use the funding for specific interventions, such as turning over certain school operations to an outside organization (contractor). GAO examined (1) what, if any, aspects of SIG pose challenges for successful implementation; (2) how Education and state guidance and procedures for screening potential contractors and reviewing contractor performance compare with leading practices; and (3) to what extent Education's technical assistance and oversight activities are effectively supporting SIG implementation. GAO surveyed SIG directors in all 50 states and the District of Columbia; analyzed Education and state documents; and interviewed officials from 8 states and school districts in those states, SIG contractors, and education experts. GAO recommends that Education (1) provide additional support to states about making evidence-based grant renewal decisions and (2) ensure that contractor performance is reviewed. Education generally supported our first recommendation but disagreed with the second. We modified our recommendation to address some of Education's concerns. Appended are: (1) Objectives, Scope, and Methodology; (2) Comments from the Department of Education; and (3) GAO Contact and Staff Acknowledgments. (Contains 3 figures and 30 footnotes.)