Communication disorders typically emerge in the formative years before a child enters school, but developmental impairments can affect classroom performance from preschool to adolescence. Speech and language skills are interdependent, which means growth in one area affects the other. The impact of communication disorders depends on internal and external factors. Extrinsically, the school environment and context influence student engagement and success. Intrinsically, the severity of the disability and age of the child has an impact on academic performance. This entry discusses communication skills disorders and how they affect preschool children, school-age children, and adolescents.