Schools are the most common venue in which children and youth receive mental health services. To organize delivery of mental health care to such a large number of children, use of school teams is often recommended. Yet, there is limited empirical literature about the composition of school mental health teams or teams’ relations to service provision. This study investigated team composition, including team multidisciplinarity (number of different types of professionals) and the presence of a community provider, and the relations of these two variables to service provision at Tier 1 (mental health promotion), Tier 2 (early intervention) and Tier 3 (intensive treatment) for 386 schools representing different school sizes, locations, and urbanicity. Results suggested team multidisciplinarity and the presence of a community provider were related to more frequent endorsement of service provision at schools. Practice and research implications are discussed including possible application to hiring decisions and further research with longitudinal data and information on service quality. Supplementary Information The online version contains supplementary material available at 10.1007/s12310-021-09493-z.