Generally speaking, the taxpayer can deduct his alimony payment but not his child support payment. He may, however, be entitled to claim the child as a dependent, although this is beyond the scope of the question.
We can deduct the alimony payment but not the child support payment. Smith paid Goode $20,000 in 2017, although he owes 24,000. The adjusted gross income depends only on how much Alimony he paid.
If he paid the full $6,000 alimony and only 14,000 of child support, he can deduct the $6,000 for an adjusted gross income of 50,000- 6,000= $46,000.
If, for example, he paid the full $18,000 in child support and only 2,000 in alimony, he can only deduct the $2,000 for an adjusted gross income of 50,000 - 2,000 =48,000.
