It has been theorized that contextual tasks support student engagement and sense making. Yet, contradictory ideas exist about the role of these tasks in lessons, and further research is needed to explore how classroom interactions can help achieve their intended purposes. Through video observation of lessons in three eighth-grade classrooms using a problem-based curriculum, I investigated how teachers and students interact around problem contexts in written tasks. I found that they discussed contexts in multiple ways, falling into five general categories: referencing, positioning, elaborating, clarifying, and meta-level commentary. Using this framework, I considered how interactions around contexts related to the authenticity of tasks as written and enacted (Palm, 2006). In several lessons, these interactions led to higher authenticity as enacted than as written. These results offer a framework for interpreting context-related classroom interactions and suggest implications for instruction and research on the role contexts might play in mathematics lessons.