We consider general supersymmetric models with (a) arbitrary matter content and (b) gauge coupling unification near the string scale $\sim {10}^{17}\mathrm{GeV}$, and derive the absolute upper limit on the mass of the lightest Higgs boson. For models without Higgs couplings to extra SU(2) triplets the bound is about 155 GeV. The bound is maximized for models with such triplets and can be as high as 205 GeV, significantly larger than previous estimates partly due to a normalization error.

• Received 6 April 1998

DOI:https://doi.org/10.1103/PhysRevLett.81.516