We present a modification to the recently developed Pair Configuration to Molecular Activity Coefficient (PAC-MAC) method in order to obtain miscibility properties of multicomponent mixtures containing polymers. PAC-MAC is a force field based quasi-chemical method originally used for rapid calculation of binary phase diagrams of small molecules. A comparison with an experimental database, containing 779 Flory Huggins chi-interaction parameters of polymer solutions, results in a correlation coefficient of 0.837 and a total root mean squared error (RMSE) of 0.593. The highest accuracy is obtained for solutions containing polystyrenes (RMSE = 0.212) or polyacrylates (RMSE = 0.308). PAC-MAC and the competitive COSMO-RS model show comparable accuracy in the prediction of solvent activities, even though PAC-MAC only uses atomic point charges instead of a quantum mechanically calculated charge distribution. PAC-MAC is a quick method for obtaining a rough indication of the mixing free energy. (C) 2016 Elsevier Ltd. All rights reserved.