child support

one month after my son found out his G/F was preg she got on medicade to pay for preg. They are not married he has full time job.She works part time. 2 months after baby born they split up. They both agreed to what he would give her a wk for support. 3 wks after they split up he got a letter from child support agengy to appear in court to arrange for child support. Here are my ? Why now is the Child supprt agency contacting him? Why cant the Ch sup agent just leave it to what my son and his ex agreed apon? How did the child support agency get involved? She says she didnt contact them and i would have thought that if the agency had to wait until the baby was born to contact him it wouldnt have tken so long. Thank you for your time.

She received public assistance, and the state is entitled to seek reimbursement. The parents can waive child support claims against each other, but they can't waive the state's claim.