Gauge and Yukawa Coupling Unification in Models with Gauge-Mediated Supersymmetry Breaking [Phys. Rev. Lett. 78, 1002 (1997)]

We examine gauge and Yukawa coupling unification in models with gauge-mediated supersymmetry breaking. We work consistently to two-loop order, and include all weak, messenger, and unification-scale threshold corrections. We find that successful unification requires unification-scale threshold corrections that are in conflict with the minimal SU(5) model, but are consistent with the modified missing-doublet SU(5) model for small tan{beta}, and large tan{beta} with {mu}{gt}0. {copyright} {ital 1997} {ital The American Physical Society}