Students with disabilities who display severe reading difficulties may require intensive interventions in order to make progress. The purpose of this study is to examine the effects of a multicomponent reading intervention implemented at two different intensities, in two separate randomized control trials, for a subset of fourth-grade students who displayed severe reading difficulties, and who had or were at risk for disabilities. We use multilevel models to examine the effect of a standard, less intensive implementation in Study 1, and of a more intensive implementation in Study 2, relative to typical school services. Analyses revealed no significant effects of treatment for the standard, less intensive implementation in Study 1. Significant effects for word reading and word reading fluency outcomes for students assigned to receive the intensive implementation were noted in Study 2. Implications, limitations, and directions for future research are discussed.