  We review the theoretical and experimental status of minimal grand unified
theories (GUTS), contrasting the failure of minimal non-supersymmetric $SU(5)$
with the success of the minimal supersymmetric $SU(5)$ and minimal
supersymmetric Flipped $SU(5)\times U(1)$ models. We show that a reasonable
value for the universal soft supersymmetry-breaking gaugino mass,
$45\GeV<m_{1/2}<1\TeV$, and a $1-\sigma$ range of the other inputs constrains
the strong coupling, $\as>.114$. We define the supersymmetric standard model
(SSM), the minimal supersymmetric extension of the standard model with gauge
coupling unification and universal soft supersymmetry-breaking at the
unification scale, as a baseline model for unified theories. We review the
structure of the allowed parameter space of the SSM and suggest sparticle
spectroscopy as the experimental means to determine the parameters of the SSM
and search for departures from the baseline SSM.
