NERC conducted its fifth biennial Grid Security Exercise (GridEx), a grid security and emergency response exercise, November 13–14, 2019. The exercise was structured as two days of distributed play and it provided an opportunity for stakeholders in the electricity industry to respond to simulated cyber and physical attacks that affected the reliable operation of the grid, fulfilling NERC’s mission to assure the reliability of the North American BPS. Led by NERC’s Electricity Information Sharing and Analysis Center (E-ISAC), GridEx V was the largest geographically distributed grid security exercise to date.