Polymer compositions are afforded flame retardancy with the incorporation of a combination of melamine polyphosphate and poly(m-phenylene methylphosphonate). The polymer compositions are for instance epoxy resins for prepegs, laminates and printed circuit boards. The epoxy resins are for example for coating electronic parts. The polymer compositions are also thermoplastics such as polyolefins or polystyrenics, useful as fibers, films or molded parts. The melamine polyphosphate may be of a fine particle size.