["Journal of School Health, Volume 96, Issue 6, June 2026. ", "\nABSTRACT\n\nBackground\nSchool mental health professionals (SMHPs) address complex student needs, yet collaboration is often hindered by role ambiguity, inconsistent preparation, and lack of consensus‐based competencies. This study identified core competencies for effective interdisciplinary collaboration in K–12 schools.\n\nMethods\nA three‐round Delphi study involved 47 SMHPs, including school counselors, psychologists, social workers, and therapists. Panelists rated and refined competencies, which were then synthesized using a multi‐step qualitative analysis into higher‐order domains.\n\nResults\nConsensus was reached on 151 competencies across four themes: (1) effective communication and relationship‐building, (2) collaborative leadership and team functioning, (3) professionalism, reflective practice, and critical thinking, and (4) cultural competence, equity, and a student‐centered mindset. Each domain emphasized interpersonal and structural mechanisms supporting coordinated, student‐focused collaboration.\n\nImplications for School Health Policy, Practice, and Equity\nThe framework offers guidance for policy, training, and organizational structures. Embedding competencies into role expectations, professional development, and evaluation, alongside protected collaboration time and culturally responsive practices, can strengthen teams and promote equity.\n\nConclusions\nThis practitioner‐informed, consensus‐based framework provides a foundation for preparing SMHPs, guiding practice, and shaping policy to support coordinated, equitable mental health services in K–12 schools.\n"]