  We present a global $\chi^2$ analysis of electroweak data, including fermion
masses and mixing angles, in SO(10) SUSY GUTs. Just as precision electroweak
data is used to test the Standard Model, the well determined Standard Model
parameters are the precision electroweak data for testing theories beyond the
Standard Model. In this talk we use the latest experimentally measured values
for these parameters. We study several models discussed in the literature. One
of these models provides an excellent fit to the low energy data with $\chi^2
\sim 1$ for 3 degrees of freedom. We present our predictions for a few selected
points in parameter space.
