I am 100% disabled and on SSI. Do I still have to pay child support?

My ex tells me I will still need to pay.

In general, the fact that you are receiving disability benefits does not automatically mean you do not have to pay child support. Your child will be entitled to receive your derivative benefits, and you may be required to pay additional child support on top of those benefits. Child support is based on two major factors, specifically the amount of income you have compared to how much income the other parent has, as well as how much time you spend with your children versus how much time the other parent spends with your children.