A request for an impairment rating using both the fourth and sixth editions of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) demonstrated two interesting facts: In the sixth edition, Table 15-34, Shoulder Range of Motion has two typographical errors. First, Grade Modifier 3 (column 6) and the Internal Rotation (IR) (row 12) lists ≤20° ER = 8% UEI; this should be ≥20° ER = 8% UEI; and Grade Modifier 4 (column 7) and IR (row 12) lists: 20° to 50° IR = 6% UEI, ≥60° IR or 10° IR to ER = 0% UEI; this should be ≥60° IR or 10° IR to ER = 10% UEI. Second, the impairment rating using the fourth and sixth editions resulted in the same total impairment. A case example presents a 54-year-old male who experienced a right shoulder strain that was determined to be a right shoulder rotator cuff tear of the supraspinatus and infraspinatus muscles. The patient was evaluated for impairment based on the range-of-motion method in the fourth edition of the AMA Guides, and 13% upper extremity impairment was determined. Using the sixth edition produced similar results, demonstrating how similar impairment ratings can be based on the fourth and sixth editions.