Get your taxes done using TurboTax

You don't add anything together.  Enter each W2 separately and the state is in box 15-17.  Don't enter the state withholding again anywhere else.  Only enter anything 1 time.  

 

Yes if you paid state tax due last year you can add those together for a federal deduction if you itemize deductions.  But most people are now taking the Standard Deduction since it has increased.