How do I deduct State Income Tax paid in 2020 on my federal return?

[DoninGA]

Do Not enter state income taxes withheld on your W-2 since the TurboTax software will enter those automatically.

To enter state income taxes paid -

• Click on Federal Taxes (Personal using Home and Business)
• Click on Deductions and Credits
• Click on I'll choose what I work on (if shown)
• Scroll down to Estimates and Other Taxes Paid
• On Other Income Taxes, click on the start or update button

On the next screen scroll down to Other Income Taxes Paid in 2020

Or enter state taxes paid in the Search box located in the upper right of the program screen. Click on Jump to state taxes paid

[Hal_Al]

State and local income tax, as well as property tax, are only itemized deductions on your federal tax return.  If you total itemized deductions do not exceed your standard deduction ($12,400 Single, $24,800 Married), you will get no benefit from trying to deduct state income tax paid.  In addition, there is a $10,000 cap on the amount of state and local tax you can deduct.