This comprehensive evaluation examines the scale-up of community-based NCD prevention programs across Kenya, Uganda, Pakistan, and Bangladesh using the RE-AIM framework. Following 45 community interventions reaching 125,000 people over 18 months, we identify key implementation determinants for successful scaling. Programs with strong community ownership achieved 73% sustainability at 24 months, while those with adequate funding and local leadership showed 89% fidelity to core intervention components.