Co-Teaching Implementation: How Do School Leaders Support Teachers?

School leaders play a pivotal role in fostering change and improvement, including via teacher-led interventions, such as co-teaching. Leaders' vision and support create the conditions for teachers to maximize the effectiveness of school interventions. However, there is limited understanding of how school leaders provide support for the intervention of co-teaching. This gap in knowledge is crucial because co-teaching has the potential to be transformative, but teachers must actively drive pedagogical changes. We conducted a mixed-methods study involving 150 Norwegian elementary schools participating in a multi-year co-teaching initiative for literacy instruction. We collected data through open and closed survey questions, inquiring about school leaders' beliefs and support practices regarding co-teaching. Our descriptive analysis examined school leaders' practices and explored potential associations with their epistemological perspectives. Our findings indicate that leaders who approach co-teaching with cautious optimism tend to provide more thoughtful support compared to those who are overly optimistic and may underestimate implementation challenges. Moreover, most leaders prioritize structural support elements while potentially overlooking psychological and emotional support practices aligned with self-determination theory (SDT). We conclude with practical recommendations for school leaders to offer support to teachers that are grounded in the principles of SDT and organized according to implementation phases.