I received a signon bonus in 2015 of which I repay a portion of that bonus in 2017. In 2015, I had to pay additional medicare tax on the amount and was capped on social security so didn't pay on that portion. My 2015 W2-C form after the repayment, shows the reduced ss and medicare amounts, but not the reduced wages. It appears I should amend the 2015 with the updated W2-C amounts for lines 3,4,5, and 6. Then account for the due tax credit from the reduction in wages by using a "claim of right" in 2017 since my tax bracket was higher in 2015. Correct? I'd rather just amend the 2015 with the wages amount since it should all wash out?
