This is a first density functional theory survey of transition-metal biliverdines (Blv), where we have chosen to focus on key Mn, Fe, Co, and Cu complexes. According to the calculations, the complexes are invariably noninnocent, featuring Blv(.2-) ligand radicals. In this, biliverdine complexes resemble metallocorroles, but the parallels are only approximate. Briefly, metallobiliverdines exhibit a much greater tendency to adopt noninnocent electronic structures than analogous metallocorroles. The O center dot center dot center dot O nonbonded contacts in biliverdines apparently preclude the formation of short metal - N bonds that, in turn, could stabilize high-valent metal ions. Thus, while most copper corroles ( Cor) exhibit diamagnetic Cu-III ground states, copper biliverdines are clearly Cu(II)Blv(.2-) species. In the same spirit, while chloroiron corroles are best described as Fe-III(S = 3/2) Cor(.2-), the analogous biliverdine derivative seems best described as Fe-III(S) 5/2) Blv(.2-), i.e., featuring a high-spin Fe-III center with long (> 2.0 angstrom) Fe - N bond distances. Overall, the results highlight the important role that steric effects may play in modulating the electronic structures and the potentially noninnocent nature of transition-metal complexes.