Improving the literacy skills of struggling high school readers remains one of the greatest challenges educators face today. Students who are two or more years behind grade level in their language arts skills have little chance of successfully completing a rigorous program of studies in high school and are the most likely to drop out. Accelerating the learning progress of such students is the explicit goal of the Ramp-Up Program in Jefferson County Public Schools in Louisville, Kentucky. The program involves a two-year course designed to accelerate the learning progress of high school students who are two or more years behind grade level in their English and language arts skills. Activities focus on helping students make rapid progress toward becoming fluent readers, developing wider vocabularies, and comprehending grade-level texts through a variety of instructional strategies. This article describes the planning, implementation and evaluation of the Ramp-Up Program. Comparisons made by the authors between classrooms with high and low levels of implementation, as well as to matched control classrooms, provide fairly strong evidence on the effectiveness of the program and the professional development involved in its implementation.