This randomized controlled trial examined the effectiveness of the UiT-ReadWell program, a reading and language intervention for children aged 7–9 (second and third grades) identified as at risk for reading disorders through national reading assessments. The intervention aimed to improve reading comprehension by targeting both language comprehension and decoding (word reading) skills. A total of 415 students were randomly assigned to either the experimental group, which received four weekly 45-min sessions over 24 weeks (92 sessions in total), or the control group, which continued with standard classroom instruction. Primary outcomes included language comprehension and word reading, whereas reading comprehension was assessed as a secondary outcome. Postintervention results demonstrated that students in the UiT-ReadWell program achieved significantly greater improvements than the control group in decoding (standardized mean difference [SMD] = 0.26), language comprehension (SMD = 0.20), and reading comprehension (SMD = 0.26). These gains were sustained at a 6-month follow-up (decoding: SMD = 0.22; language comprehension: SMD = 0.16; reading comprehension: SMD = 0.24). Mediation analyses revealed that improvements in reading comprehension were facilitated by improved word reading and language comprehension, accounting for ∼27% and ∼34% of the total effect, respectively. This study highlights the efficacy of a comprehensive intervention that simultaneously addresses word reading and language comprehension, leading to lasting improvements in reading comprehension. The findings have significant theoretical and practical implications, offering valuable insights for future research and educational practices to support children at risk for reading difficulties. (PsycInfo Database Record (c) 2026 APA, all rights reserved)