A wide body of evidence shows that investing in high-quality early childhood development programs can have significant economic and social benefits, particularly when targeted to disadvantaged children. Scaling up these programs has proven challenging, with evidence often showing mixed results in achieving and sustaining significant outcomes. This paper distills and extents recent research on the economics of child skill development and documents four early childhood development programs designed with an emphasis on home visiting (three home visiting programs and one more comprehensive program that includes a home visiting component) to demonstrate the potential benefits of this type of intervention if implemented at scale. Our findings show that to effectively scale up and achieve full social and economic benefits from these investments, programs must be designed with a clear understanding of the fundamentals of skill formation and mechanisms driving the outcomes as well as the context in which scaling will occur. Additionally, comprehensive data collection must be funded and shared across government agencies and research organizations. In other words, programs must be designed with scaling in mind.