This work argues the mass term in the neutrino wavefunction propagator is due to entanglement with its associated origins. The implication being that neutrino flavor is conserved in weak processes and shared among all particles emanating from the last interaction with a nucleon. In so doing, the neutrino mass propagator is real but not ascribed to the neutrino outside of entanglement. The proposed theory will be readily testable in that reactor and solar neutrinos will oscillate but both muon decay neutrinos and accelerator neutrinos created by pure lepton interactions will not oscillate..