The transition to formal schooling is a large contextual change, which for many children in U.S. begins with the year of kindergarten. To better understand the challenges of this transition, the present study examines the extent to which children experience transition difficulties in five salient areas: making friends, following schedules, meeting academic demands, working within groups, and being organized. Using a sample of 688 kindergarteners from 45 classrooms, we found that challenges in the transition to kindergarten were prevalent based on teacher report. More than 70% of the children were reported to have difficulty in at least one area, and over 30% of children had challenges in all five areas. Meeting academic demands and being organized were two of the most common challenges kindergarteners experienced. Gender and IEP status consistently predicted transition difficulties, in that boys struggled more than girls, and children with disabilities (on the basis of IEP provision) were more likely to have difficulties than those without IEPs. Overall, this work highlights the need to support children during the transition to kindergarten.