Early Head Start (EHS) is a national program that addresses the needs of low-income pregnant women and families with children under the age of 3. EHS was authorized as part of the Head Start Act of 1994. Since its beginning, EHS has established a legacy of providing comprehensive child development and family support services to infants, toddlers, and their families. Rigorous research has shown that EHS has positive impacts on children’s cognitive, language, and social–emotional development and improves family self-sufficiency and parental support of the children’s development. This entry describes the EHS program, summarizes findings from its national longitudinal impact evaluation, and concludes with information about the status of the program today. It is important to note that the program effects reported here come from ...