Professionals working with infants, toddlers, and preschoolers are likely to encounter challenging behavior. This webinar reviews the ABCs of behavior (antecedent, behavior, consequence) and helps professionals identify the function of behavior. Dr. Hardy explains the ways in which multi-tiered systems of support (MTSS) can be utilized to manage challenging behavior for all children, but especially children with disabilities or who have experienced trauma. The use of tally sheets, forms, and checklists to inform decisions that support positive behavior and sustain behavioral change is also addressed.