Purpose A biopsychosocial case formulation is an important tool for understanding complexity and guiding treatment for people with intellectual disabilities. It has been suggested that formulation meetings develop staff understanding of individuals they support. This study aims to explore the change processes that occur as a result of professional team formulation meetings, and the mechanisms that facilitate and hinder these events. Design/methodology/approach Eight clinicians who took part in multi-disciplinary team-based formulations in an inpatient mental health service for adults with intellectual disabilities were interviewed. Interviews were examined using thematic analysis. Findings The key themes identified were: “gaining information”, “altered thoughts” and “focused goals”. These themes were supported by “collaborative working” and “time for reflection” and were hindered by “poor communication and interaction” and inconsistent “staff attendance”. Originality/value Multi-disciplinary team formulation meetings may have a number of change processes that affect staff knowledge and perception of the people that they support. The facilitation of these processes should be a focus for further development.