A tax deduction is an amount that you can deduct from your taxable income to lower the amount of taxes that you owe. You can choose the standard deduction—a single deduction of a fixed amount—or itemize deductions on Schedule A of your income tax return.

If the total for your itemized expenses is greater than the standard deduction for your filing status, it makes sense to itemize. Allowable itemized deductions include mortgage interest, charitable gifts, unreimbursed medical expenses, and state and local taxes.