This article clarifies important conceptual issues associated with the assessment of pain and considers reasons why pain should be considered in impairment and disability ratings. The authors address conceptual issues rather than specific pain assessment methods and limit the discussion to the musculoskeletal and neurologic injuries seen most frequently during impairment disability evaluations. Several groups of experts worked on the AMA Guides, and little is known about which elements of the AMA system are well substantiated and which need revision. In addition, the AMA Guides, as actually used, often differ from the guides as written. Self-reports that disability applicants provide about their experiences provide a first-person perspective that, in principle, may be important to assessors. Pain and “unbearable” sensations cannot be incorporated into impairment evaluations in the AMA Guides because pain is inherently subjective and because pain and its effects must be analyzed at the level of the whole person. In summary, although the AMA Guides, Fifth Edition, seems to support including pain in impairment ratings, this support is vitiated by inconsistencies in the conceptualization of impairment, contradictory information about how examiners should interpret pain, and inadequate guidance about how examiners should combine subjective and objective data.