Early Childhood Special Education (ECSE) provides services for children from birth to kindergarten age who qualify under IDEA. The Individualized Family Service Plan (IFSP) outlines the services and supports for infants and toddlers, focusing on the family's priorities and natural environments. For preschoolers, the IEP may specify services to meet outcomes in developmental areas in preparation for kindergarten. Research shows the benefits of early intervention, though ongoing studies are needed to identify the most effective programs.