An extensive body of research has investigated the developmental risks of low family income during early childhood, finding substantial evidence of income-based gaps in children’s development that emerge by age 3 years. This study focuses on how two- generation education services provided to low-income families during this important developmental time period through the federal Early Head Start (EHS) program may provide benefits to children. EHS serves pregnant mothers, infants, toddlers up to age 3 years, and their families, offering center-based and home visiting services to families with low incomes. While EHS has been rigorously evaluated, finding positive impacts for parents and children, we know less about how service type (center-based, home-visiting based or both) and dosage is associated with children’s development among the diverse families served by contemporary EHS programs who are ages 1, 2 and 3 years old. (author abstract)