This experiment employed a functional magnetic resonance imaging (fMRI) working memory task to examine how three sub-component processes: (1) Proactive Control, (2) Filtering, and (3) Disengagement contribute to a mechanistic explanation of the relation between working memory and reading skill. Results suggested that skilled readers deploy more prefrontal resources when cued proactively about task-relevant features than do less-skilled readers. In contrast, reading skill was not related to activation associated with attention-filtering or successful disengagement.