You can use any part of the repayment that was originally taxable to you as a "claim of right" if the repayment amount is over $3,000 in one year. This will be a direct reduction to your income dollar for dollar in 2018. You cannot adjust anything on your 2017 return and this advice assumes the employer has included the taxable portion of your moving expenses in your wages on your W2 for 2017.
