This chapter provides the age-to-age Series, a handout series of children, intended for therapists to use as resources for parents, caregivers, teachers, or other systemic partners. Each handout provides a description of typical characteristics for the age group, along with expected challenges, tips for caregivers, and indicators of when caregivers should seek support. For ages three to six, each handout is divided into half-years to emphasize the differences that occur during that year of maturation. For ages seven to twelve, the handouts characterize the year as a whole. It is important to consider ones child's overall development, in addition to his or her chronological age, birthday, and cognitive abilities, when deciding the best time for ones child to start kindergarten. This hangout explains that four-year-old child often have behaviors that parents find challenging or concerning, but which are a normal part of development. There are fewer challenges with more than six-year-old child than there were earlier in the year.