Child abuse and neglect remain a significant US problem affecting millions of children and families. Therefore, the Children’s Bureau of the Administration for Children and Families asked the Institute of Medicine/National Research Council to update the 1993 National Research Council report, Understanding Child Abuse and Neglect.1 Twenty years later, despite important progress, many challenges remain. Research since 1993 makes clear that child abuse and neglect are serious public health issues affecting victims in all areas of functioning throughout life.