Effective May 1, 1997, all physicians and chiropractors who rate workers’ compensation permanent partial disabilities (PPD) are required to become members of the Nevada Division of Industrial Relations panel of rating physicians and chiropractors. The State of Nevada previously used the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Second Edition, but now uses the Fourth Edition to rate PPD. To become panel members, Nevada physicians must complete a State-approved training course and a written examination. On March 17, 1997, Nevada conducted its first mandated written examination, for which the questions were supplied by the American Board of Independent Medical Examiners (ABIME). The ABIME exam covers the knowledge, skills, and abilities necessary to perform independent medical exams, and ABIME has conducted physician testing in Canada, the United States, Australia, and Hong Kong. The trend toward written credential tests for evaluating physicians is likely to expand because of the shortage of highly qualified examiners. The AMA Guides is the most widely used standard not only for rating permanent impairment but also as an index to PPD, and other jurisdictions are likely to follow the example of Nebraska and to require physicians to obtain training and demonstrate competency in impairment rating.