On January 1, 2005, Senate Bill 899 went into effect in California and substantially changed the method of determining permanent disability for California’s industrially injured workers. Physicians no longer determine work capacities or tolerance using medically determined work restrictions. The AMA Guides to the Evaluation of Permanent Disability, 5th Edition, is now the basis of medical evaluation for permanent disability awards for the California workers’ compensation system. As a result, the vocational evaluation process used prior to January 1, 2005, no longer meets the requirement of substantial medical (vocational) evidence by the workers’ compensation industry. A different approach and structure is needed to meet the criteria for substantial medical evidence determined by physicians, and substantial vocational evidence as determined by vocational experts. Vocational experts must provide a factual basis for their work and conclusions. They must be able to understand and apply Workers’ Compensation Appeals Board rules and regulations, case law, and critical analysis such as causality and apportionment as defined by the California Labor Code Sections 4663 and 4664 or be at risk for having their work rejected.