The AMA Guides to the Evaluation of Permanent Impairment, (AMA Guides), Fifth Edition, is the most widely used basis for determining impairment and is used in state workers’ compensation systems, federal systems, automobile casualty cases, and personal injury cases. The AMA Guides is used in most state workers’ compensation jurisdictions: 25 states use the fifth edition; 10 use the fourth edition, 1 state uses a hybrid of the fourth and fifth editions, and 2 states use the third edition, revised; 6 states use their own state-specific guidelines, and 6 do not indicate a specific guideline. Statutes may or may not specify which edition of the AMA Guides to use nor how to use them. In addition, many states use a statutory schedule for amputations, hearing loss, visual loss, hernias, and disfigurement, and other states use the AMA Guides for nonscheduled injuries. The AMA Guides often is used to quantify the extent of injuries resulting from an automobile casualty or personal injury. Insurers may use an impairment rating as a factor in setting reserves and determining the settlement value of a claim, and attorneys may use this information to quantify the effects of an injury. A four-page table displays uses of the AMA Guides in state workers’ compensation plans, including the edition most commonly used, the statute/code, comments, and relevant websites.