You have to fill out form 3903 to claim the moving deduction to prevent the code P amount from becoming taxable. Because some many employers reimburse moving expenses that are not tax deductible, the IRS makes you jump thru these hoops to be sure tax is paid on the reimbursement for non deductible stuff.
Type> moving expenses for a job related move <in the find box. Do enter ONLY the code P amount when asked if you were reimbursed