The amount of support payments or your ex wife's income has no bearing on who gets to take the dependency exemption. What does your divorce decree say in regards to who gets to take the child as a dependant? It may not say or it might state that you and your ex wife get to have the dependency for tax purposes every other year. Or that you solely get it . Check the decree. But no matter what it says if your ex wife is the custodial parent she can give you an signed 8332 form so that the IRS knows you are entitled to take the child as a dependent. You can also claim the Child Tax Credit. Your wife as the custodial parent can claim the Earned Income Credit if she otherwise qualifies. If you work together you can both legally benefit from the credits available on your tax returns.