We proposed a hybrid equation of state for CO2-polymer systems that utilizes the Peng-Robinson (PR) equation of state for the molecular excluded-volume effects and the van der Waals attractions, and equations from the statistical associating fluid theory (SAFT) for the polymer intrachain correlations and for the short-ranged forces due to weakly polar or association interactions. The numerical performance of the new equation of state was tested by its application to correlating the PVT behavior of pure CO2, including both the vapor liquid coexistence densities, the vapor pressure, and the specific density of condensed CO2 at near-critical and supercritical conditions, and to the volumetric properties of high molecular weight alkanes and a few representative polymers. With the parameters from the original PR equation of state for nonpolar monomeric fluids and additional ones to account for the solvent polarity and the solute degree of polymerization, the new equation of state was successfully used to calculate the phase behavior of CO2-polymer systems, including the vapor-liquid equilibria of ternary systems.