FL child support for a NCP equates to approximately 20% of your income. It doesn't matter what his income is or the way he derives it, the formula will still equate to 20% of your income. Additionally, since you never filed your agreement for no child support with the courts, you were building arrears that whole time. In FL when you have arrears, they can and will take up to 65% of your net income to pay the regular support plus the arrears. They typically will not reduce child support when there is an arrearage. When you asked for a review, you opened the door for a possible upward modification which is apparently what happened. Your base amount may have gone down, but your overall payment went up to pay the arrears. They probably are adding on to pay towards the arrearage. Even if your salary reduced and you would have typically been entitled to a reduction, because you had arrears, they are making sure payment is applied toward that. And yes, once a child is emancipated in FL, they do not reduce the amount of child support if there are other children, and especially if there is arrears.