Reading Success is an individualized teacher-guided literacy program proven for 663 students who experienced difficulty with reading. The students had learning disabilities, mild mental retardation, and behavior challenges; were at risk for school failure; or were transitioning from speaking Spanish to English and experiencing literacy problems. Pupil progress data, as measured by progress over time in various reading curricula, reflected student gains of a half year to more than 3 years per year of instruction. Monthly curricular progress data ranged from 0.03 to 6.80 months' gain per month of instruction. Many students showed equivalent gains on standardized informal reading inventories, with some passing a statewide test for the first time. Thirty-five special education students returned to regular education programs. All students received the basic lesson, reflecting reading research-based practices. Some students received specialized interventions that focused on three critical reading behaviors (word reading accuracy, reading speed, reading comprehension) and written language (composition, mechanical skills). (Contains 10 tables and 2 figures.)