you do not get a $10,000 tax credit if that's the amount repaid, you only get a credit for the income taxes paid on that $10,000. so on what form or schedule did you use and what amount did you enter?
if you repaid it in the same year as received, box 1 of your w-2 should already exclude the bonus payment so this is no additional deduction on that year's 1040. . if the repayment was in a subsequent year your choice is between an itemized deduction which will not produce any tax benefits unless your itemized deductions exceed your standard deduction.
is line 17 of schedule A greater than whichever standard deduction among the following, based on your filing status, applies to you? if not there is no benefit from itemizing
single $13850 (note 2)
joint return or qualifying surviving spouse $27,700 (note 1)
head of household $20,800 (note 2)
married filing separately $13,850 (note 1)
note 1: add $1,500 for age 65 or older or blind, each
note 2: add $1,850 for age 65 or older or blind, each
***********************
your other option is to recompute your income taxes for the year you received the bonus by reducing box 1 of the w-2 by the gross repayment
the reduction in taxes for the year you received the bonus is taken on the return for the year in which you made repayment and is entered on schedule 3 line 13b
