The Fermi GBM provides simultaneous low-energy spectral and temporal measurements for all GRBs within the LAT FOV. The combined GBM and LAT effective energy range spans more than 7 energy decades from 10 keV to 300 GeV. The GBM extends the energy coverage from below the typical GRB spectral break at ~100 keV to above the LAT's low-energy cutoff for inter-instrument calibration. Furthermore, the GBM's sensitivity and FOV are commensurate with the LAT's to ensure that many bursts will have simultaneous low-energy and high-energy measurements with similar statistical significance. The GBM also assists the LAT in detecting and localizing GRBs rapidly by providing prompt notification to the ground of a burst trigger. Finally, the GBM provides coarse GRB locations over a wide FOV that can be used to repoint the LAT at particularly interesting bursts (both inside and outside the LAT FOV) for gamma-ray afterglow observations. These locations are also sent to the ground to notify external follow-up observers.