Adolescents with reading disability (RD) participated in a randomized controlled trial evaluating the efficacy of a multiple-component reading intervention with motivational components (PHAST). A total of 514 youth in 6th, 7th, and 8th grade formed instructional groups (4-8) that were randomly assigned to one of three conditions-one of two PHAST interventions (additional comprehension or fluency training) or a remedial reading control condition. Intervention occurred in participants' schools, 40-60 min daily, 3-5×/week, for 100-125 hr total. Over four outcome assessments, multilevel growth models evaluated intervention/control differences in growth over time, and post-intervention effect sizes. The two PHAST interventions were associated with equivalent positive outcomes, and their data combined. PHAST participants out-performed Control participants on 8 of 16 outcomes, demonstrating greater growth on standardized and experimental reading and spelling outcomes. PHAST-instructed students demonstrated higher sense of reading competence, and increased attributions of reading success to their own abilities. Intervention effect sizes (Hedge's g) comparing PHAST versus Control growth were larger for foundational reading skills (.78 for nonword decoding, .56 for word identification) than for reading comprehension (.36 for passage comprehension), for which effects were more equivocal. An effect size of .61 was obtained for sense of reading competence. A year later, the PHAST participants demonstrated continued improvement on later-developing reading skills like word reading efficiency, reading fluency, and reading comprehension. Intensive reading intervention in middle school can produce gains on multiple dimensions of reading skill and motivation and foster continuing growth of higher-order reading skills. Educational Impact and Implications Statement Can reading intervention still make a positive impact for adolescents with persistent reading problems-those who failed to adequately respond to or never received early reading intervention? We developed and evaluated an intervention for middle school youth who were reading significantly below age and grade-level expectations and who met criteria for reading disability. We offered 100-125 hr of small group remedial intervention designed to address both the reading and the motivational problems of students with persistent reading disabilities in 6th, 7th, and 8th grade. We compared the research-based PHAST Program with an equivalent amount of remedial reading instruction offered by Special Education teachers. These control group students made reading gains over the course of their intervention classes, but students in the PHAST intervention showed significantly greater improvement on standardized reading and spelling tests and on a self-report motivation measure of perceived reading competence. A year after their programs ended, PHAST students continued to improve on later-developing reading skills like word reading speed, reading fluency, and reading comprehension. These findings are encouraging because they demonstrate that multiple components of these older readers' reading systems still can be changed with intensive research-based intervention in the early years of adolescence.