In automatic R-parity-conserving supersymmetric (SUSY) SO(10) models, the simplest way to accommodate realistic fermion masses is to demand that the light Higgs doublets are linear combinations of the {10} and {126̄} grand unified Higgs representations. We study the realization of this mixed light Higgs property consistent with doublet-triplet splitting in a minimal R-conserving SUSY SO(10) model. We then discuss predictions for neutrino masses and mixings in this model as well as its implications for proton decay. © 1995 The American Physical Society.