Your total itemized deductions must be less than your standard deduction, so TurboTax is using the standard deduction because you pay less tax, or get a bigger refund, that way. Schedule A is not used when you take the standard deduction instead of itemized deductions. The standard deduction amounts were greatly increased starting with 2018 tax returns, and some itemized deductions were eliminated or limited. Therefore many people who used to itemize deductions now find that the standard deduction is higher than their itemized deductions.
