Students who struggle with reading have particular trouble with expository text. Instruction in text structures has been shown to be effective for improving expository reading comprehension. However, few studies have been conducted specifically with upper elementary aged struggling readers. To address these issues, we developed a new intervention, "Structures," to improve the expository text comprehension of 4th and 5th grade struggling readers. In this study, we conducted a randomized control trial to assess the promise, usability, and feasibility of one component of the intervention designed to teach students to identify and discriminate the five text structures. Forty-five 4th and 5th grade struggling readers were randomly assigned to intervention or business-as-usual conditions. Students in the "Structures" condition were taught to identify and discriminate among the five text structures used by authors of expository text: description, sequence, cause/effect, compare/contrast, and problem/solution. At post-test, experimental students (n = 24) statistically significantly outperformed control students (n = 21) on a structures identification measure (d = 0.94). No other statistically significant differences were found. However, a practically (but not statistically) significant effect size was found on an oral retell measure (d = 0.29). Results also indicate the materials were usable for teachers and it was feasible to implement the intervention in a school setting. The implications and future directions of the development of remaining components in the "Structures" intervention are discussed. [This paper was published in "Reading and Writing: An Interdisciplinary Journal" (EJ1193961).]