According to the Working Group on California Earthquake Probabilities, the likelihood of magnitude 6.7 and larger earthquakes occurring somewhere in California in the next 30 years is near certainty. Given the high level of earthquake risk in California, it is crucial to develop policies for risk mitigation, emergency preparedness, risk transfer and insurance, and buildings and infrastructure design that are informed by the best available science on earthquakes. Consequently, there is a need for improved understanding of the seismic risk in the State, including a better characterization of elements that comprise the risk: hazard, exposure, and vulnerability.