This issue of The Guides Newsletter introduces a new feature, Case Study, that illustrates some of the challenges encountered in rating shoulder impairment. The history presents the case of a 50-year-old, right-hand dominant white male evaluated for impairment due to left shoulder pain, stiffness, and weakness. His initial injury occurred at work in December 2001 when he used his left arm to prevent himself from falling. After five months of nonoperative treatment, including one subacromial steroid injection, physical therapy, and a second opinion, he underwent open subacromial decompression and acromioplasty and open distal clavicle excision. He returned to work and pain resolved after a year but recurred in September 2003. The patient was examined 19 months after the surgery, and the examining physician evaluated the patient's clinical status at that time, reviewed diagnostic studies performed, diagnosed maximum medical improvement, and, using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), assessed 11% whole person impairment. Readers are encouraged to use the materials presented to this point to prepare their own rating that they can compare with an analysis (published elsewhere in this issue) that reviews the examining physician's report and finds that it was inconsistent with the AMA Guides and was erroneous in certain key points.