This pilot feasibility study applies the RE-AIM Implementation Science Framework to examine the implementation and preliminary signals of the effectiveness of integrating the Group–Early Start Denver Model (G-ESDM) in an early childhood education center serving under-resourced communities. Five preschoolers diagnosed with autism, their caregivers, and teachers participated for 6 months. Standardized assessments documented improvements in adaptive, cognitive, and communication functioning for most participants. The majority of parents reported reduced daily stress and a greater ability to maintain their employment. A staff survey indicated high perceived feasibility and acceptability of the intervention along with a strong intent to continue treatment after the study concluded. Fidelity improved over time with staff integrating G-ESDM techniques at an acceptable fidelity level (>70%) by the second half of the study. Findings across all RE-AIM Implementation Science Framework domains indicate that incorporating the G-ESDM into this setting was feasible, acceptable, and potentially beneficial for children and their families in underserved communities. (author abstract)