Problem solving has long been a focus of research and curriculum reform (Kilpatrick 1985; Lester 1994; NCTM 1989, 2000; CCSSI 2010). The importance of problem solving is not new, but the Common Core introduced the idea of making sense of problems and persevering in solving them (CCSSI 2010, p. 6) as an aspect of problem solving. Perseverance is important for solving meaningful mathematical problems, and when student thinking drives the curriculum, a lack of perseverance is a real barrier to the development of interesting and significant mathematics. This article describes the efforts of a cross-grade level team of mathematics teachers from Holt Public Schools in Holt, Michigan, to understand what kinds of systemic supports, provided across grade levels, encourage students' perseverance when problem solving. The teachers used "lesson study" (Fernandez and Yoshida 2004) as the professional development structure to support their learning, and they conducted a series of lesson studies in three mathematics classrooms across grades 7, 9, and 10. The authors share what the team learned about supporting perseverance not just within particular lessons but also throughout students' mathematics experiences from middle to high school.