The International Association for the Study of Pain and the World Health Organization have added a new diagnosis, chronic primary pain, and a new pain mechanism, nociplastic pain, to physicians' vocabularies. This new concept explains many pain presentations that have lacked a method of classification. The implications of this new concept regarding treatment options and for determining maximum medical improvement and permanent impairment are evolving. Incorporating the chronic primary pain diagnosis and the nociplastic pain mechanism into practice will require planning and action by physicians. In this article, the history of these terms and their applicability for the AMA Guides to the Evaluation of Permanent Impairment and related publications will be discussed.