Fixed cutoff dates regulating school entry create disadvantages for children who are young relative to their classmates. Early and late school enrollment, though, might mitigate these disadvantages. In this paper, we analyze in a first step which factors determine school entry, if entrance screenings allow for early and late enrollment. Second, we study whether children benefit from a delayed school entry. Using data on a compulsory school entrance screening of a German federal state, we show that children with impairments in cognitive, socio-emotional, and motor development as well as health but also young children are less likely to be recommended to start school. Delaying school entry allows the delayed children to improve, although their developmental status remains below average. School entrance screenings, thus, induce more flexible school entry rules that attenuate performance differences within a class and, as a result, mitigate disadvantages for children being young compared with their classmates.