Deep-level transient spectroscopy has been used to characterize electronic defects inn-type GaN grown by reactive molecular-beam epitaxy. Five deep-level electronic defects were observed, with activation energiesE1=0.234±0.006,E2=0.578±0.006,E3=0.657±0.031,E4=0.961±0.026, andE5=0.240±0.012 eV. Among these, the levels labeledE1, E2,andE3are interpreted as corresponding to deep levels previously reported inn-GaN grown by both hydride vapor-phase epitaxy and metal organic chemical vapor deposition. LevelsE4andE5do not correspond to any previously reported defect levels, and are characterized for the first time in our studies. ©1998 American Institute of Physics.