If we have indistinguishable particles, we must use Fermi-Dirac statistics. To Identical and indistinguishable particles, we use Bose-Einstein statistics. And, to distinguishable classical particles we use Maxwell-Boltzmann statistics. I have a system of identical but distinguishable particles, where the second level has a degeneracy. I was reading at Wikipedia: "Degenerate gases are gases composed of fermions that have a particular configuration which usually forms at high densities." My question is: Should I use Fermi-Dirac statistics in this case? I'm confused. I was reading Reif and it seems that I should use Maxwell-Boltzmann just to nondegenerate gases. But if my system is made by distinguishable particles, it seems that I should use MB statistics.