Health insurance and payment of uninsured expenses are considered to be additional child support in Texas. In theory, the parent who pays for uninsured medical expenses (like copays, prescriptions, and deductibles) is supposed to send those receipts to the other parent in a timely fashion, usually within 30 days. If the receipts are provided too late, the court may not make the other parent pay. Since the math is determined according to the discretion of the court, it can be expensive to get the answer. I generally suggest that the order require the sending of unreimbursed medical receipts EVERY month on the 15th of the month. That way, it is predictable, and the saving up of receipts is discouraged. The mechanism to determine the outstanding medical expenses, and who pays them is a Motion to Determine, which is very similar to a Motion to Determine Arrearage.