The present study examined the efficacy of using an informal reading inventory to assess literacy levels in elementary-age deaf students, grades 3-5: the period when the gap between deaf and hearing learners often begins to widen, and the need to identify and remediate specific skill deficits becomes increasingly imperative. Emphasis was placed on exploring how results of a formative assessment can inform instruction across a variety of literacy skills (e.g., word identification, reading accuracy, reading fluency, reading comprehension, writing) and among a broad range of learners. A case study approach is used to present in-depth overviews of the performance profiles of three students; also, instructional implications of the findings are discussed. The results illustrate how an informal reading inventory can be used to design interventions that are differentiated and targeted based on identified needs in both the code- and language-related domains of literacy skill development.