§ 4915. Prohibited practices. An external appeal agent shall not, with  respect to external appeal activities, permit or provide compensation or  anything of value to its employees, agents, or contractors based on: (a)  either a percentage of the amount by which a claim is reduced for  payment or the number of claims or the cost of services  for  which  the  person has denied authorization or payment; or (b)  any  other  method  that  encourages  the upholding of an adverse  determination.