This document discusses congressional oversight of cybersecurity information sharing. It begins by defining congressional oversight and describing the tools Congress uses for oversight, such as hearings, investigations, and control over nominations and funding. It then discusses how information sharing has grown as a policy approach for cybersecurity and the challenges it poses for oversight. Specifically, information sharing limits Congress's role in overseeing policy and many oversight tools are less effective when applied to information sharing, which can disadvantage Congress and limit its ability to ensure policy goals are being met. The nature of cybersecurity problems and reliance on the private sector also influence the challenges of overseeing information sharing approaches.