Purpose: This study assessed the effectiveness of a Tier 2 intervention that was designed to increase the phonemic awareness skills of low-income preschoolers who were enrolled in Early Reading First classrooms. Method: Thirty-four preschoolers participated in a multiple baseline across participants treatment design. Tier 2 intervention for beginning sound awareness was provided twice weekly in small groups over 6 weeks by trained teachers and speech-language pathologists (SLPs). Results: The intervention was successful for 71% of the children, as indicated by medium to large effect sizes. Comparisons between children who did and did not qualify for intervention suggest that Tier 2 intervention helped narrow the gap in beginning sound awareness that had begun to emerge before treatment. Although children receiving special education and those learning English as a second language were enrolled in the classrooms, they were not overrepresented in the group qualifying for Tier 2 intervention, and most who did qualify demonstrated a positive response to intervention. Conclusion: In a relatively short period of time, preschoolers' phonemic awareness skills were increased through small-group Tier 2 intervention provided by teachers and SLPs. Findings indicate the potential of Tier 2 interventions to positively impact the future reading skills of children who are at risk for later reading difficulties.