We report a study of the spin moment in single crystal Nb(1−y)Fe(2+y) with y=0.015 using spin-dependent Compton scattering in conjunction with ab initio electronic structure calculations. From the experiment, we find that the total spin moment is 0.245±0.004μB. Comparison of the measured spin density with theoretical results from linearized muffin-tin orbital calculations determines there to be a ferrimagnetic arrangement of Fe moments, with the 2a Fe site aligned antiparallel to the bulk moment. There is a small moment on the Nb site, also antiparallel to the net moment. The orbital moment has been determined to be 0.02±0.02μB.