Significant differences exist regarding spinal impairment rating among the Third Edition Revised, and the Fourth and Fifth Editions of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides). Table 1 summarizes the rating criteria used in these three editions. The AMA Guides, Third Edition Revised used only the method that was subsequently labeled the Range of Motion (ROM) Model or Method to assess impairment. The AMA Guides, Fourth Edition, introduced the Injury or Diagnosis-related estimates (DRE) Method, but it had a limited role, primarily as a differentiator, when a patient's final category of disability was in doubt. The AMA Guides, Fifth Edition retains both ROM and DRE, but they are termed methods rather than models. The DRE Method remains the principal means to evaluate an individual who has an injury, but changes were made regarding when and how it is used. In specified cases, the ROM Method is used to assess impairment not caused by an injury (eg, multilevel involvement, recurrent radiculopathy, or multiple pathologic episodes that produce alteration of motion segment integrity or radiculopathy). Table 2 presents seven exemplar cases that demonstrate the differences in impairment ratings among the three editions, and the text discusses the ratings and differences among the outcomes according to edition used.