Cubic-plus-chain (CPC) equation of state (Sisco et al., Industrial & Engineering Chemistry Research, 2019) is used to model vapor-liquid and liquid-liquid phase equilibria for different polymer-solvent systems. Polypropylene (PP), high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polystyrene (PS) polymers are modeled with various solvents. Different factors including solvent effect, molecular weight, pressures, temperatures, polydispersity, and polymer concentration are investigated to study their effects on modeling the phase behavior with the CPC equation of state. CPC modeling results are compared with the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state and experimental cloud points available in the literature. The CPC equation proved to be capable of modeling the phase behavior for different polymer-solvent systems since it showed good agreement with different experimental cloud points across various temperature ranges. A temperature dependent binary interaction parameter is used in modeling the phase behavior using the CPC equation for polymers as well as different well-defined binary mixtures.