I think there may have been a bug. We filed as "married filing jointly." I assigned my wife's income to her and mine to me. TurboTax apparently calculated it all as belonging to one person, as it calculated that we paid excess social security tax. After I responded to an IRS 12C letter, there was many months of waiting and wondering. We finally received a notice that the IRS corrected our return. After a call to the IRS and lots of Googling, I calculated our SS withholding and discovered that the exact amount our refund was off was identical to our combined withholdings minus the maximum Social Security tax of $8,537.40. Individually, we were both under that amount. I won't rule out user error, but the fact that TurboTax documentation states that TurboTax calculates that for you leads me to believe that there was an error in the programming of the calculations.
