The employer over-withheld pre-tax health insurance.  He then repaid the over deduction by creating an earnings code called additional pay and removing the taxes so the employee was paid the full amount.  This takes care of the employee.  However, the pre-tax deduction is over-stated by this amount.  It appears you cannot enter a negative pre-tax deduction on an adjustment to correct this.  What is the best way to move the additional pay to a reduction in the pre-tax deduction?