Abstract: A polymer composition is provided including copolymer particles bearing phosphorus acid groups dispersed in an aqueous medium, wherein the polymer composition is substantially-free of water soluble phosphorus acid compounds. Also provided is a monomer composition containing at least one phosphorus acid monomer and a method of preparing the polymer composition from the monomer composition. The monomer composition is substantially-free of inorganic phosphorus acid compounds. A method is provided for applying the polymer composition to a substrate. The polymer composition is useful as a coating composition to prepare coatings for metal substrates, which have improved solvent resistance.