Some injuries to the extremities can be associated with multiple injuries or diagnoses, and, in such cases, evaluators should recall that the functional history adjustment can be considered only for the single highest rated condition. This Case Example illustrates the proper rating methodology using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition section on The Upper Extremities. A 58-year-old male automotive mechanic fell at work on an oil-slickened floor and landed directly on his left outstretched hand and wrist, as well as the lateral part of his left elbow. At maximum medical improvement (MMI), the individual complained of moderate pain at rest and severe pain with repetitive forceful gripping and grasping. Radiographs taken at MMI showed a healed distal radius fracture in anatomic position with no posttraumatic arthritis and no carpal instability. The AMA Guides, Sixth Edition, allows use of only one of two methodologies: the Diagnosis-based impairment (DBI) methodology or the range-of-motion (ROM) method. Because ROM findings at the left elbow and wrist were recorded as normal and because the greater impairment that is causally related to the injury is used to rate the impairment, the DBI methodology is appropriate here. Only a single diagnosis is rated per region, and a case that involves more than a single region in the same extremity can be rated for separate impairments based on the separate regional conditions or diagnoses.