The polar decomposition method for Mueller matrices proposed by Lu–Chipman has been demonstrated and validated for many applications. However, in some situations, e.g., when analyzing the Mueller matrix of birefringent turbid media with Mie-sized scatterers acquired in reflection geometry, the method may suffer from limitations due to the assumptions required by this method. Here we extend the Lu–Chipman method and show that it can provide more reasonable results for these situations. The method has been validated experimentally with turbid phantoms. Thus, this Letter may prove useful in tissue polarimetry.