Pain Medicine has its roots in multiple primary specialties and has developed into a discrete specialty with disparate practice styles. Its identity is in flux and is threatened by forces that may fragment this new field before it can set firm roots. The public health crisis of under treated pain parallels medicine's struggle to adequately classify Pain Medicine as a specialty. We review the case for Pain Medicine as a discrete discipline, with specialized knowledge, treatments, training and education. Without recognition of the specialty of Pain Medicine, and resolution of the fragmentation of the field throughout healthcare, medicine's approach to the current problem of under treated pain is likely to continue to be inadequate.