Gauge unification and the supersymmetric light Higgs mass

We consider general supersymmetric models with: a) arbitrary matter content; and, b) gauge coupling Unification near the String scale $\sim {10}^{17}$ GeV, and derive the absolute upper limit on the mass of the lightest Higgs boson. For a top-quark mass $M_t$= 175 GeV, and depending on the supersymmetric parameter $\tan \beta$, this mass bound can be as high as $\sim$ 200 GeV.