Before December 31, 2018, if you paid alimony, you could deduct it from your taxable income; and if you received alimony, you had to include it in your taxable income. Both of those treatments of alimony were changed when the new tax bill (Tax Cuts and Jobs Act) passed in late 2017.
Under the new law, alimony (also known as spousal maintenance), is not deducted from the payor’s taxable income, and is not included in the payee’s taxable income. It is now a non-taxable transaction, like child support.
If the alimony order was in effect before December 31, 2018, then that alimony is still deductible (by the payor) and included (by the payee). That is why there is still a line on the Form 1040 for deducting and including alimony.
But since it has now been five years since the change in law, there are fewer and fewer cases in which the old tax treatment still applies.