When taxpayers file their federal individual income tax return, they choose between claiming the standard deduction and claiming a series of itemized deductions, such as the state and local tax (SALT) deduction and the mortgage interest deduction, to lower their taxable income.

Among the many changes introduced by the Tax Cuts and Jobs Act of 2017 (TCJA), one of the most significant was nearly doubling the standard deduction and scaling back some itemized deductions. Taxpayers typically choose to itemize only if their total itemized deductions exceed the standard deduction. So, when TCJA nearly doubled the standard deduction while also scaling back some itemized deductions, the portion of taxpayers choosing to itemize declined.

The recently enacted One Big Beautiful Bill Act (OBBBA) permanently extended, expanded, and augmented reforms surrounding the standard deduction and itemized deductions. This data brief puts these new reforms in historical context by evaluating trends in itemized deductions after TCJA became law.