Yes, TurboTax will prevent you from double dipping. On the summary screen at the end of the Form 2441 interview you will see that it has subtracted the FSA amount from your total child care expenses, leaving you with zero expenses eligible for the credit, and zero credit. Form 2441 lines 10 and 11 will be zero or blank. Schedule 3 lines 2 and 13g will be zero or blank, or Schedule 3 will not be included in your return if you have no other credits. But you still have to file Form 2441.