Direct neutrino mass measurements probe Beyond Standard Model physics ex-
tensions which are employed to explain the finite neutrino masses, which are
in contradiction to the minimal Standard Model of Particle Physics but now
firmly established through the observation of neutrino flavor oscillations. While
being insensitive to the absolute neutrino mass scale oscillation experiments
provide lower limits, depending on the neutrino mass hierarchy. The upcom-
ing KATRIN experiment will improve the upper limits set by the Mainz and
Troitsk experiments (≤2 eV/c2 ) down to 200 meV/c2 and will probe the quasi
degenerate regime of neutrino mass hierarchy. I will discuss fundamentally new
laboratory approaches currently under development to either confirm a posi-
tive KATRIN result independently or to push the sensitivity limit towards the
40 meV/c2 range, the predicted lowest neutrino mass in case an inverted mass
hierarchy is realized in Nature. Major financial support by the U.S. Depart-
ment of Energy, Office of Science, Office of Nuclear Physics to the University of
Washington under Award Number DE-FG02-97ER41020 is acknowledged.