Nonprofit organizations addressing societal challenges such as hunger, poverty, and racial inequities seek to grow the impact of their promising solutions to these problems—scaling social impact. Yet, local, community-based nonprofits often struggle to identify a path to scale their impact. To address this problem, we partnered with eleven nonprofits engaged in social impact scaling. By integrating insights on scaling from our nonprofit research partners together with academic research on scaling across a range of disciplines, we outline a framework for scaling community-based nonprofits and the marketing practices that support it. Our research advances a two-stage social impact scaling framework. We term this framework T-Shaped Scaling. Within our framework, the vertical bar of the T refers to scaling deep, grounding solutions within a community, and the horizontal bar of the T represents scaling wide, adapting and transferring the scaled deep solutions to new communities. This framework advances both our conceptual and practical understanding of social impact scaling. Finally, we explore the policy implications of social impact scaling and call on researchers in marketing to further investigate the scaling strategies and marketing practices that grow social impact.