I gave my mother custody of my son 7 years ago and now welfare is taking me for child support.do I have to pay if his grandmother has legal full custody?

I gave legal full custody of my son to his granmother 7 years ago.do I have to pay child support

Custody simply means your mother is responsible for the child. It has nothing to do with support. I suspect your mom has applied for public assistance. So the state is looking for support to offset what they have to pay. And yes you are responsible. Unless your mom adopted the child, you are still responsible.

Yes, you do, and the babies father should be gone after also.

Custody is just that, and then the bio parent that odes not have custody pays child support

The problem Gradma does not care about the support, but since she could not support the child without receiving some level of welfare, they want you to repay them, for money you should have been paying for the care of the child