  We look at a number of simple, but representative, models of extended
electroweak gauge structures, and present the general contributions to a_muon
from the heavy Z' and W' electroweak gauge bosons. Of the models we have
examined, none can explain the observed discrepancy between the current
experimental value of a_muon and the Standard Model prediction if we require
that the gauge fields explain the discrepancy by themselves. In the context of
models with new matter fields as well as the additional gauge fields discussed
here, however, the gauge field contributions to a_muon can be a substantial and
important part of the discrepancy.
