Which of the following deductions typically requires a taxpayer to maintain additional documentation?

Itemized deductions are typically subject to stricter documentation requirements than the standard deduction. This is because itemized deductions consist of various specific expenses that taxpayers may claim, such as mortgage interest, medical expenses, state and local taxes, charitable contributions, and certain unreimbursed business expenses. Insufficient documentation can lead to disallowance of these deductions during an audit or review by the IRS.

Taxpayers claiming itemized deductions must keep detailed records, including receipts, invoices, and other documentation that substantiate the amounts being claimed. This level of documentation helps to ensure accuracy and compliance with tax laws, as these deductions need to directly correlate with out-of-pocket expenses made throughout the year, unlike the standard deduction, which is a fixed amount that does not require additional documentation.