Although calculations of interstitial site dimensions suggest that R2Fe14B compounds (R = rare earth) should not be able to absorb N atoms to form R2Fe14B-Nx nitrides, several literature reports of nitrogenation and improved magnetic properties have appeared. We found that Nd2Fe14B does absorb a considerable amount of nitrogen, up to N/M = 0.26, decomposing the Nd2Fe14B to nanocrystalline Fe and unidentified nitride and other species.