Enter the taxes withheld on the Federal Section of TurboTax under
Deductions & Credits
Estimates and Other Taxes Paid
Other Income Taxes START or UPDATE
Scroll down to "Other Income Taxes Paid in (TAX YEAR)
Click START for "Withholding not already entered on a W-2 or 1099"
Answer "Yes" for "Do you have any tax withholding you haven't entered yet?"
Select "Pennsylvania" from the state drop-down under State withholding and enter the amount.
Continue
Done
The tax will flow to the state return.