Can a third party service provider file a claim with the DOL for underpayment for services when the plan prohibits assignment except to the extent of payment (e.g., anti-assignment against all other rights but to receive payments)? Can they proceed with a claim when the TPA is alleging that the provider failed to provide adequate information? Any suggestions on where I can look to find more information on third parties and DOL enforcement activity on underpayment claims? Thanks in advance.