The children's book "Two Is for Twins" celebrates twins and illustrates the many "twos" in a child's world. The uniqueness of twos does not have to mean separate classrooms for twins in child development programs, preschool, or elementary school settings. With recent dramatic increases in the US twin population, how should educators address the separation of twins in different classrooms? This article will answer this question by providing a synthesis of research studies on twins and their separation in school and recommending best practices for teachers and school leaders when deciding to include or separate twins by classroom. (Contains 5 online resources.)