Deep level transient spectroscopy (DLTS) measurements have been performed on Schottky diodes fabricated on MBE grown InGaAs/GaAs heterostructures. The dominant electron trap in this material is found at a depth of 0.30eV below the GaAs conduction band and is believed to be the previously observed M3 defect. Two other defects, at depths of 0.50eV and 0.58eV below the GaAs conduction band, were also observed. Defect depth profiling shows the 0.50eV defect to be spatially locatednear the heterointerface. The 0.58eV defect is not observed near the heterointerface but is observed in large concentrations deep in the GaAs epilayer. Optical DLTS measurements reveal deep defects at 0.54eV and 0.31eV above the InGaAs valence band as well as a large, broad peak, most likely consisting of several energy levels with varying capture cross sections,located at the heterointerface. Two carrier accumulation peaks were also seen in the CV carrier profiling measurements and are suggested to be due to two heterointerface defects located at 0.68eV and 0.87eV below the GaAs conduction band.Thermally stimulated capacitance measurements also indicate minority hole emission in this n-InGaAs/N-GaAs heterostructure.