But the money was supposed to be paid while the child was still a minor. So should the parent who supported the child on their own while the child was still a minor just be out of luck? I don't think so. Let's look at this another way. You have a hypothetical situation where your 17 year old child is very sick, $200,000 worth of medical expenses are racked up. Now your court order says the parents are supposed to split medical expenses 50/50 because both parents are responsible for the medical care of the child. So the custodial parent pays their half but the noncustodial parents doesn't and the bill collectors are hounding the custodial parent for their money and the custodial parent is having to do without some things so they can pay. The child is now 18. Should the child get the $100,000 and the custodial parent just be left holding the bag? No I don't think so. It's no different for putting a roof over the child's head, paying for houshold utilities, buying food to feed the child, etc, etc, etc.