Interdisciplinary collaboration (IC) is a critically important theme generally, and of particular significance in school mental health (SMH), given the range of people from different disciplines who work in schools and the various systems in place. Reflecting the move to a true shared school-family-community system agenda, the collaborative context in schools includes school-employed mental health professionals (e.g., school psychologists, school counselors, school social workers), health professionals (e.g., school nurses, speech pathologists), special and general educators, collaborating mental health professionals from the community, school administrators, families and family advocates, resource staff, and others. Notably, as SMH is becoming an increasing force in the United States and in other countries, an expanded approach is being emphasized with community professionals joining those in schools to augment the work that is occurring, increasing the likelihood that community mental health will actually reach youth and families and that typically underresourced schools receive enhanced resources and support to offer the full intervention continuum of mental health promotion. In this article, a diverse team of professionals (early career psychologists, a social worker, a special educator, and faculty in psychology and special education) working on implementing a large-scale study presents study background and themes related to IC as the study plays out. First, the authors describe their interdisciplinary team's collaborative approach toward implementing a multicomponent mental health and classroom intervention package for high school youth with social, emotional, and behavioral disabilities (EBD) and their families. They then discuss obstacles in sustaining ICs with schools and present strategies for overcoming them.