A mathematical model is presented to analyze the kinetics of solid-state polymerization of bisphenol A polycarbonate. The reaction kinetic model incorporated in the solid-state polymerization model is a hybrid of a molecular species model and a functional group model derived from the original model developed by Flory. The solid-state polymerization model allows for the calculation of time evolution of complete polymer chain length distributions in a polymer particle at different radial positions under various reaction conditions. The model simulations show that large polymer particles exhibit strong intraparticle diffusion resistance to phenol, and as a result, the chain length distribution varies significantly from position to position in the polymer particle. Also, some polymer chains have very large chain lengths, several times larger than the average chain length, and some polymer chains have less than 10 repeating units even with a very large average molecular weight. The model simulations also show that one of the most important kinetic parameters that affect the performance of solid-state polymerization is the end group mole ratio in the prepolymer used for solid-state polymerization. The more the end group mole ratio deviates from its stoichiometric ratio in a prepolymer, the longer the reaction time needed to obtain high molecular weight polymer in the solid state. Also, the stoichiometric imbalance in the prepolymer severely limits the maximum obtainable molecular weight. The model simulation shows that an increasing polymer crystallinity during the solid-state polymerization has an effect of increasing the concentrations of catalyst and reactive end groups and hence the polymerization rate.