The AMA Guides to the Evaluation of Permanent Impairment (Guides) is a well-known standard for quantifying the medical loss associated with an injury or illness. The Arizona Workers’ Compensation Board has adopted the most recent, the Sixth Edition of the American Medical Association (AMA) Guide to the Evaluation of Permanent Impairment as the basis for rating permanent partial impairment under the Arizona’s Workers Compensation Insurance. The rating for impairment can be found in Arizona Administrative Code (“A.A.C.”) R20-5-113(B).
Although use of the AMA Guides is generally required by most of the states, in Arizona the state’s case law gives some discretion to the physicians that evaluate the impairment whether to use the Guides or not. Arizona courts recognize that a physician may rely on the AMA Guides if the physician finds them to be an appropriate measure of impairment, but if not, the physician may use other appropriate rating criteria and adoption of AMA Guides is not mandatory.
The permanent impairment benefits are determined once the individual’s condition is stabilized and is not expected to improve with additional medical treatment. This event is what’s known as Maximum Medical Improvement (MMI). Once a physician concludes that the individual has reached MMI, the next step is determining if he is back at his pre-injury condition or whether he has a permanent impairment. In case of the latter, the Workers’ compensation benefits in Arizona pay either permanent partial disability or permanent total disability benefits up to a limit.