In this study we explore the care work of homeroom teachers, who, in many educational systems, are responsible for the social and emotional wellbeing of students in their homeroom classes. The study is based on in-depth semi-structured interviews with 70 homeroom teachers in Israeli elementary, middle and high schools, and draws on Tronto's ethics of care combined with a practice-based approach to expertise. We argue that homeroom teachers develop unique, practice-based expertise, based on four distinct but interrelated forms of care work: intuitive work, relational work, emotional work and sensory work. Homeroom teachers develop their care expertise amid institutionalised deficiency in professional training in care work and a lack of organisational support for this work in schools. These structural problems detract from teachers' ability to provide competent caregiving, a necessary element in Tronto's ethics, and they constitute a warning sign concerning the capacity of k-12 education to provide good care.