In addition to the "sunshine tax", us Californians also deal with the "seismic tax" since it is one of the most seismically active areas in the world. So it is not surprising that California has adopted the 2009 IBC and incorporated it within the California Building Code in order to keep us all safe.
Plus, California’s Office of Statewide Healthcare Planning and Development (OSHPD) has issued specific interpretations that affect the way evaporative cooling equipment serving healthcare facilities are seismically qualified/certified.
All other states and local codes have also adopted the IBC or revised their local codes exactly like the IBC.
Below you'll find a go-to-guide on what you need to know about seismic terms and concepts. It's a little long but it has answered a lot questions I am frequently being asked of late.
So prepare yourself and your projects for the Big One.