Cybersecurity is an enterprise-level risk that affects every organization, yet significant gaps in directors’ knowledge and oversight of cybersecurity still exist at the boardroom level. The 2017 edition of the NACD Director’s Handbook on Cyber-Risk Oversight is constructed around five core principles designed to enhance the cyberliteracy and cyber-risk oversight capabilities of directors of organizations of all sizes and in all industries. Given the importance of this issue, NACD has made this handbook available publicly.