We report the photoelectron spectrum of the aminomethoxide anion (H2C(NH2)O-). The electron affinity (EA) of the aminomethoxy radical is determined to be 1.944(1) eV. Transitions to the ground ((X) over tilde (2)A '') and first excited ((A) over tilde (2)A') electronic states of aminomethoxy are observed, with the term energy measured to be T-o((A) over tilde <- (X) over tilde) = 0.085(1) eV. A long vibrational progression is observed for the transition to the ground (X) over tilde (2)A '' electronic state of aminomethoxy, primarily consisting of OCN bending and HNH wagging vibrations, leading to the assignment of these two fundamental vibrational frequencies of H2C(NH2)O center dot (X) over tilde (2)A ''. The gas-phase acidity of aminomethanol is calculated at the G4 level of theory to be Delta H-acid(OK)O = 374.0 kcal mol(-1), which, when combined with the experimental EA of aminomethoxy in a thermochemical cycle, provides a determination of the O-H bond dissociation energy, D-0(H2C(NH2)O-H) as 106(2) kcal mol(-1). Comparisons of the EAs and T-0((A) over tilde <- (X) over tilde) for the aminomethoxy, methoxy, ethoxy, and hydroxymethoxy radicals provides insight into how the substituent group affects the electronic structure of singly substituted alkoxy radicals.