Teachers in primary classrooms who are emphasizing high-level comprehension of complex texts are seeing young children hit comprehension thresholds that were previously only visible among older readers. However, most primary level reading interventions focus on word recognition skills or reading increasingly difficult leveled texts. This article describes the assessment procedures needed to identify the children who need additional support and to diagnose their specific comprehension needs. It also describes research-validated protocols for improving narrative comprehension and informational text comprehension.