Wave energy converter (WEC) devices are designed to sustain the wave-induced loads that they experience during both operational and survival sea states. The extreme values of these forces are often a key cost driver for WEC designs. These extreme loads must be carefully examined during the device design process, and the development of a specific extreme condition modeling method is essential. In this paper, the key findings and recommendations from the extreme conditions modeling workshop hosted by Sandia National Laboratories and the National Renewable Energy Laboratory are reviewed. Next, a study on the development and application of a modeling approach for predicting WEC extreme design load is described. The approach includes midfidelity Monte-Carlo-type time-domain simulations to determine the sea state in which extreme loads occur. In addition, computational fluid dynamics simulations are employed to examine the nonlinear wave and floating-device-interaction-induced extreme loads. Finally, a discussion on the key areas that need further investigation to improve the extreme condition modeling methodology for WECs is presented.