Purpose: Research shows that school leadership and working conditions strongly predict teacher turnover, but less empirical work has explored how school leaders grapple with this aspect of their work. This paper investigates how school leaders across diverse geographic and institutional contexts understand human capital challenges and construct approaches to improve adult culture and teacher retention. Research Methods/Approach: This cross-case analysis includes interviews with 23 school leaders from four different public-school systems (charter, suburban, rural, urban). Using both inductive and deductive coding approaches, we analyze how school leaders understand and approach human capital challenges and the logics they invoke in doing so. Findings: Perceiving teacher supply and dismissal challenges as outside of their control, leaders primarily focused on managing the adult culture of their schools to improve teacher retention. This focus raised additional challenges for school leaders around generating teacher buy-in and attending to teacher wellbeing. Whereas school leaders across different contexts named similar strategies for generating teacher buy-in around school or systemwide goals, some leaders framed focusing on teacher wellbeing as being in tension with their responsibilities to student outcomes. Implications: This work contributes to the literature on school leadership and teacher retention, which highlights school leadership as a point of intervention for stemming teacher attrition. Understanding how school leaders locate challenges, construct priorities, and manage the human capital side of their work is paramount to improving school leader preparation and support, teacher retention, and student outcomes. [This paper was published in "American Journal of Education" v130 n3 2024.]