Interdisciplinary collaboration is critical to address the multiple and varied needs of students with social/emotional and behavioral (SEB) challenges. Yet little is known about the nature of collaboration between two specialist groups who commonly support them: behavior analysts and mental health specialists. Considering expectations for collaboration, and the potential challenges unique to this partnership, we conducted a series of interviews in the U.S. state of Tennessee to explore these specialists' experiences and perspectives around collaboration. We used a qualitative description approach, which led to identifying themes related to (a) specialists' preparation to collaborate, (b) facilitators and barriers to effective collaboration, and (c) supports needed to collaborate more effectively in their current roles. Specialists from both groups felt their pre-service training inadequately prepared them to collaborate with one another. They identified several factors that impacted their ability to meaningfully collaborate and expressed needs for cross-discipline education, collaborative conversations, and training on "soft skills" to partner more effectively. We highlight distinct and overlapping perspectives within and across themes between behavior analysts and mental health specialists and discuss implications for improving the quality of these important partnerships.