For decades, approximately 600,000 taxpayers paying alimony to a former spouse have been able to deduct those payments on their annual taxes. Not anymore, as of January 1, 2019.
This amount will no longer be deductible, and may be found to disproportionately hurt women in divorce negotiations.
Agreements signed before January 1 will still qualify for the deduction so if you are close in reaching a final agreement, keep an eye on the calendar. This has no bearing on child support payments as they are considered separate under tax law.
You can read all the details here, https://www.nytimes.com/2018/07/02/us/politics/new-tax-law-rich-divorce.html, and then please be sure to consult with your legal, tax and financial advisors before signing anything.