A comprehensive pseudoequilibrium melting model for pure random copolymers of vinylidene chloride (VDC) with methyl acrylate (MA) monomers is developed. The model incorporates a composition-dependent surface free energy contribution to the melting point depression of these copolymers. Total exclusion of noncrystallizable copolymer units from the crystal phase is assumed for this copolymer system, and this leads to a thin lamellar crystal morphology. A physical model for these crystals is shown, and a large lateral surface area relative to the volume of the crystal is suggested. The surface to volume ratio increases with increasing copolymer composition. The model developed in this work has an excellent fit to experimental melting point data. A nonlinear composition dependence was observed for the measured melting temperatures of these copolymers, and this was well predicted by the model.