Despite considerable attention over the years, the claimed ionization energies of the methyl- and dimethyl-substituted amidogen radicals are surprisingly diverse. In this paper, the available evidence is reviewed and the controversies are highlighted. New ab initio calculations have been performed, using the ACES2 package and the G1 and G2 methodologies, and evaluated for the amidogen radical, NH2. It is concluded that the inexpensive G1 and G2 calculations, including scaling, allow a confident prediction of the ionization energies of CH3NH (9.8 +/- 0.1 eV) and CH3NCH3 (9.1 +/- 0.1 eV).