The Supreme Court of Pennsylvania on June 20 2017 found the AMA guides unconstitutional for PPD rating in workers compensation cases.
Pennsylvania law provided that the degree of impairment shall be based on an evaluation by a physician…pursuant to the most recent edition of the AMA guides.
This delegation to the AMA to determine impairment, allowed a private sector entity to make policy in violation of the non delegation doctrine.
Here is a link to the decision.