Well, alimony is not taxable or deductible for any divorce that was finalized after Dec 31, 2018. The only issue is who owns the property and who can take the itemized deduction for property taxes and mortgage interest. If he is still a part-owner of the property, and pays half the mortgage, he can deduct half the interest and property taxes (if he itemizes) and you can deduct the other half (if you itemize). If he is NOT an owner, then the payment is non-taxable alimony to you, and you can deduct all the property taxes and mortgage interest.
