Abstract: This guide, part of the U.S. Department of Education's Innovation in Education series, profiles eight charter high schools that are helping to close the achievement gap between low-income, minority, and special need students and their peers. Although all the schools are unique, six similar characteristics unite them. The schools are mission-driven; focus on college preparation; teach for mastery; provide support; value professional learning; and hold themselves accountable. The schools were chosen in 2005 from over 400 charter high schools that are meeting academic targets under the No Child Left Behind Act (NCLB) and are closing achievement gaps by holding students to high academic standards.