Even before COVID-19 shuttered schools around the world, rapidly expanding access to high-quality learning opportunities for all children was critically needed. The pandemic has only exacerbated the magnitude, inequity, and urgency of this need. While many innovations exist - often emerging outside the formal education system - the question has increasingly become how to scale and sustain those that are most effective at improving learning for all. In response, the Center for Universal Education (CUE) at Brookings has been investigating efforts to scale and sustain evidence-based initiatives leading to large-scale improvements in children’s learning. CUE is implementing a series of Real-time Scaling Labs (RTSL), in partnership with local institutions in several countries, to generate evidence and provide practical recommendations around the process of scaling in global education - encouraging a stronger link between research and practice. This report focuses on one of the scaling labs launched in Tanzania in 2018 in collaboration with the Campaign for Female Education (CAMFED). It examines the process of implementing, adapting, and scaling the Learner Guide Program, which delivers life skills and mentorship provided by local female secondary school graduates (Learner Guides) to secondary school students as part of an 18-month volunteer program, in collaboration with the Ministry of Education, Science, and Technology (MoEST) and the President’s Office, Regional Administration and Local Government (PO-RALG).