This article presents a conceptual framework for analyzing how researchers and district leaders perceive and navigate differences they encounter in the context of research-practice partnerships. Our framework contrasts with images of partnership work as facilitating the translation of research into practice. Instead, we argue that partnership activity is best viewed as a form of joint work requiring mutual engagement across multiple boundaries. Drawing on a cultural-historical account of learning across boundaries (Akkerman & Bakker, 2011) and evidence from a study of two long-term partnerships, we highlight the value of the concepts of "boundary practices" in organizing joint work and "boundary crossing" as a way to understand how differences are recognized and navigated. The framework has implications for how partnerships can surface and make productive use of difference in organizing joint work and for how funders can better support the work of research-practice partnerships.