The use of exclusionary discipline (ExD) was compared for U.S. public pre-kindergarten (Pre-K) and K-12 grades within the same school. ExD rates were 10 times higher in K-12 than in Pre-K when calculated for all schools but ExD rates were comparable for schools that reported at least one case of ExD in Pre-K. Additionally, disparities in the use of ExD were observed for both Pre-K and K-12 schools: higher rates were found for boys relative to girls, for Black children relative to White children, and for charter schools relative to non-charter schools. While most schools did not use ExD, when they did, they did so at high rates. The use of ExD appears to be associated with school-level factors including a culture of use. (author abstract)