A randomized trial evaluated the efficacy of 17 Early Head Start (EHS) programs. 3,001 low-income families with a pregnant women or an infant under 12 months were assigned to a treatment or control group. Data were collected when children were 1, 2, 3, and 5 years old. Analyses examined (1) impacts at ages 2 and 3 (while services were being offered) and at age 5, and (2) contributions of early education experiences across children's first 5 years...