For decades, alimony payments have been deductible by the payer spouse and included in the taxable income of the recipient spouse. That changed. Starting in 2019, spousal support payments will no longer be deductible to the payer or considered income to the recipient.
Modifying divorce decrees filed before December 31, 2018 will be subject to the old tax rules unless the modified agreement specifically states that the 2019 tax treatment will apply.
The elimination of the alimony deduction will result in greater tax revenue for the government, higher tax liability for payers and possibly lower payments to recipients as the loss of the deduction may lead payers to negotiate lower payments.