Preliminary efficacy data are reported for a research-based reading intervention designed for struggling readers in high school. PHAST PACES teaches (a) word identification strategies, (b) knowledge of text structures, and (c) reading comprehension strategies. In a quasi-experimental design, 268 intervention and 83 waiting list control students meeting criteria for reading disability were assessed before and after their semester. After 60 to 70 hours of PHAST PACES instruction, struggling readers demonstrated significant gains on standardized tests of word attack, word reading, and passage comprehension and on experimental measures of letter–sound knowledge and multisyllabic word identification relative to control students. An average effect size of .68 was revealed across these outcome measures. One year follow-up data on 197 PHAST PACES students revealed an average trend to decelerated growth after the intervention, except for passage comprehension outcomes that demonstrated continued growth over follow-up.