Why did I receive a separate tax bill from Arizona saying I owed for underpayment of taxes. Turbotax has always figured this out before so I could include the amount when I pay the taxes to state.
No one can see your tax return so no one in the user forum knows why AZ is billing you. Your only proof that you paid your AZ tax due is your own bank or credit card record. Do you have that?
The program can figure an underpayment penalty based on what you entered into the interview screens and the fed/state reserve the right to figure it on the info they have on file which may not be the same. Also they can add interest. And in the state interview you may have indicated that you wanted the state to compute the penalty instead of the program.