WARD v. WAL-MART STORES, INC. ASSOCIATES' HEALTH & WELFARE PLAN, 1999 U.S. App. LEXIS 24831 (6th Cir. September 30, 1999) (unpublished)-Wal-Mart's health plan sought subrogation, then reimbursement, of the $101,526.56 in medical benefits it had paid to an employee when the employee settled her negligence suit (arising out of the accident) against the City of Lansing for $200,000. The district court was correct in awarding reimbursement, but not subrogation, because the City of Lansing was not liable for medical expenses (only non-economic damages), and therefore did not meet the plan’s definition of a "third party liable for benefits." The district court was in error, however, when it used the Federal Common Law theory of unjust enrichment to force the Plan to pay a pro rata deduction of the employee’s attorney’s fees out of the reimbursement it sought. "Federal courts may not apply Common Law theories to alter the express terms of written benefit plans, as one of the primary purposes of ERISA is to ensure the integrity and primacy of the written plans." Plan may recover only the portion of the recovery in excess of the attorneys' fees and then sue to recover the fees from the attorneys.