When a child reaches the age of majority (usually eighteen) or graduates high school, that normally is a basis for stopping child support for that child, unless the parent is obliged to help pay for that child’s college education.

Whether payments stop at age eighteen or at graduation from high school depends on the law of the state. Many states say payments stop at the later of those two events (assuming the child will graduate high school in a normal amount of time).

If only one child is the subject of a support order, the parent who is obliged to pay child support (the obligor) can stop making payments when the child reaches eighteen or graduates high school. The obligor does not have to go to court to seek permission to stop payments.

If there is more than one child who is subject of a support order, the right of the obligor to reduce payments when the oldest child reaches the age of majority will depend on the wording of the court’s support order.

If support is set at a certain amount per child (for example, "child support shall be $200 per month for each of the three children"), then the obligor may reduce payments by $200 as each of the three children reach the age of majority. Under this example, child support would be $600 per month when all three children were under eighteen; $400 per month when the oldest child reached eighteen; $200 per month when the middle child reached eighteen; and no support when all three were over eighteen.

If, on the other hand, child support for three children was set as a lump sum for all children (for example "child support for the three children shall be $600 per month"), then the obligor must keep paying $600 per month until the youngest of the three children reaches eighteen, unless the obligor goes to court and obtains a reduction in child support.

When the oldest child reaches the age of majority, that can be a basis for a court to reduce support, but it is not an automatic basis for doing so. The court will look at a variety of factors, including the current income of the parents and needs of the remaining children. If the income of the parents has remained the same and the needs of the remaining two minor children are the same, the obligor can expect that the amount of support for the remaining two children will decrease. The amount of reduction will not necessarily be one-third, however. Applying Illinois’ child support guidelines, for example, the obligor could expect that child support payments would be reduced from 32 percent of his or her net income to 25 percent of net income.

When considering whether to go to court to seek a reduction in child support based on the oldest child reaching majority (or when seeking a reduction on some other basis), the obligor should consider how the guidelines apply to the obligor’s current income. If the obligor’s current income has risen significantly since the last order, a new child support order for two children may actually be more than the guideline amount for three children since support for three children was set at a time when the obligor’s income was lower.

To elaborate on the examples just given, assume that at the time of divorce five years ago an obligor had a net income of $22,500 per year. If the obligor had three children, and Illinois guidelines applied, the obligor would pay 32 percent of net income for child support, which is $7,200 per year or $600 per month. Assume further that the court’s order (or the parents’ settlement agreement) provided that child support for the three children shall be $600 per month. Five years later, the obligor’s income has doubled (to a net income of $45,000). If the obligor now wants to reduce child support because the oldest child has reached eighteen, the obligor could be in for an unpleasant surprise if the obligor went to court.

While it is true that a child’s emancipation (reaching the age of majority) is a basis for changing child support, the guidelines when applied to the obligor’s current income would actually result in an increase in child support. Applying the Illinois guidelines of 25 percent of net income for obligors with two children, support would now be at $11,250–a $4,050 per year increase from the old support order even though there is one less child to support.

Similar considerations apply to the parent to whom support is due. If the parent receiving support has had a significant increase in income from wages or elsewhere, that parent may not be able to obtain a significant increase in support if the state’s guidelines or other legal principles would shift more of the support obligation to the parent receiving support.

Sometimes it is best not to rush off to court, even though one may be tempted to.

SOURCE: FindLaw