I am also seeing this problem. I have $412 reported as "Other withholdings" that appear in 25c of my 1040. I can't find where it could have come from in any of the forms and information I submitted to TurboTax.
However, it seems like the "Additional Medicare tax" I owe is greater than what I have calculated on my own, by the exact same amount. In the end, the taxes I owe are what I expect based on my own calculations. I just don't know where this amount could be coming from and want to be sure I'm reporting accurately.
