What magnitude of earthquakes are designed into buildings?

I know I'm not a practicing engineer yet but I will graduate next year with my BS in Civil/structural. From what I have done in my cles the ASCE has specific codes for calculating earthquake loads depending on the seismic area your in. I do not live in a highly active zone so I don't know the exact numbers for a place like Japan or California, but I do know when we design buildings in the US we design them so they deform when they exceed their max load instead of fail. That way we have time to notice the damage before they collapse after a large earthquake. I must say though that Japan has some of the best earthquake engineering in the world and it shows with how well their infrastructure held up.