I am filling out my Railroad W2 and have an issue. Based on Box 1, my federal withholdings should be X. However, they are Y in Box 2. I have a nonzero item in Box 12DD, which according to the back of my W2 is nontaxable. If I take Box 1 - Box 12DD, this is almost perfectly Y (the number in Box 2). When I input this in TurboTax, it's trying to say I owe the difference between X and Y because I underpaid my federal taxes. How do I correctly account for this? Do I adjust Box 1 such that it's Current Box 1 - Box 12DD? I don't think I owe this X-Y amount. Thanks in advance!