TurboTax will automatically choose the best option based on the calculations. If you've entered itemized deductions and TurboTax is calculating that your standard is best, you may have limitations or other adjustments on your Form 196 (itemized deductions) that is bringing your total itemized deduction down below the standard. If you're using TurboTax Desktop, you can view the Form 196 and 196 Adjustment worksheet to see how the deduction is calculated.
