Texas child support laws use the Percentage of Income Formula to calculate how much support the non-custodial parent must pay. This formula applies a percentage to the income of the non-conservatorship parent based on the number of children that need support. The Texas divorce court may order either or both parents to pay child support until the child is 18 years old or until graduation from high school, whichever occurs later; until the child is emancipated by marriage or a court order, until the child dies, or for an indefinite period if the child is disabled. A child support order in Texas should be revisited periodically through the court for potential modification. The most common reason child support is modified is due to a change in conservatorship, income, or a child of the support order reaching emancipation.