Child support is financial assistance paid by the non-custodial parent to the custodial parent. The purpose is to help support the child. Child support does not automatically end when the child turns 18. A probate and family court judge can extend child support until the child is 23 years old, or beyond. The paying parent cannot simply stop paying. A court order is needed. In order to halt child support payments, that parent must file a Motion to Modify Child Support. It then must be approved by the judge.