I also discovered this error in TurboTax. It does not correctly adjust Form IT-201, line 28, for this accrued market discount on US Treasury bonds. I did an override, and then when I went to e-file, TurboTax says that it cannot e-file with an override so I have not yet e-filed my New York return. It seems like it is a bug in TurboTax. TurboTax correctly handles the accrued market discount in my California return.
EDIT: TurboTax does *not* correctly handle this accrued market discount in the California return. I manually made the adjustment but without having to override anything. See my other reply in this thread if you want to know where.
