  We consider the Z'/Z mass hierarchy in a supersymmetric model in which the
U(1)' is broken in a secluded sector coupled to the ordinary sector only by
gauge and possibly soft terms. A large mass hierarchy can be achieved while
maintaining the normal sparticle spectra if there is a direction in which the
tree level potential becomes flat when a particular Yukawa coupling vanishes.
We describe the conditions needed for the desired breaking pattern, to avoid
unwanted global symmetries, and for an acceptable effective mu parameter. The
electroweak breaking is dominated by A terms rather than scalar masses, leading
to tan beta ~ 1. The spectrum of the symmetry breaking sector is displayed.
There is significant mixing between the MSSM particles and new standard model
singlets, for both the Higgs scalars and the neutralinos. A larger Yukawa
coupling for the effective mu parameter is allowed than in the NMSSM because of
the U(1)' contribution to the running from a high scale. The upper bound on the
tree-level mass of the lightest CP even Higgs doublet mass is about c x 174
GeV, where c is of order unity, but the actual mass eigenvalues are generally
smaller because of singlet mixing.
