Metal Building Systems, which represent a large portion of low-rise construction in the United States, are typically composed of steel moment frames and slender tapered beam sections. To answer questions concerning frame behavior in large seismic events, three full-scale frames were tested on the UCSD/NEES Large High Performance Outdoor Shake Table. Based on their observed behavior, two new seismic force resisting systems are in development. To assess the collapse reliability of the new systems, large parametric studies are being conducted. Ten beam-column assemblies were cyclically tested in the UCSD Powell Labs to provide data for the strength and cyclic performance of lateral buckling of tapered I-beams. Test data will be used to validate inelastic finite elements used to model the cyclic behavior of the metal building frames.