Is Stuttering a Schedule A disability?

Is Stuttering a Schedule A disability? Hey, does anyone know whether stuttering/stammering is a Schedule A disability, in the United States? I've been googling but I can't find any clear answer on what Schedule A includes. There was mention of intellectual, psychiatric, and mental disabilities, but I don't know if stuttering falls under these. On the other hand, a job I just applied for had "speech impairment" listed as a considerable disability.