The duration of child support is determined by the state that originally entered the order (in a divorce or parentage case). In Kansas, child support duration is governed by KSA 23-3001(b):
“(b) Regardless of the type of custodial arrangement ordered by the court, the court may order the child support and education expenses to be paid by either or both parents for any child less than 18 years of age, at which age the support shall terminate unless:
“(1) The parent or parents agree, by written agreement approved by the court, to pay support beyond the time the child reaches 18 years of age;
“(2) the child reaches 18 years of age before completing the child’s high school education in which case the support shall not terminate automatically, unless otherwise ordered by the court, until June 30 of the school year during which the child became 18 years of age if the child is still attending high school; or
“(3) the child is still a bona fide high school student after June 30 of the school year during which the child became 18 years of age, in which case the court, on motion, may order support to continue through the school year during which the child becomes 19 years of age so long as the child is a bona fide high school student and the parents jointly participated or knowingly acquiesced in the decision which delayed the child’s completion of high school. The court, in extending support pursuant to subsection (b)(3), may impose such conditions as are appropriate and shall set the child support utilizing the guideline table category for 12-year through 18-year old children. For purposes of this section, “bona fide high school student” means a student who is enrolled in full accordance with the policy of the accredited high school in which the student is pursuing a high school diploma or a graduate equivalency diploma (GED).”
In essence, this means that child support is usually paid until the child reaches the age of majority (which is 18 years of age or June 30 if the child’s 18th birthday occurs while the child is attending high school). The obligation to pay child support may be extended beyond the child’s majority by agreement between the parties, but it cannot be imposed by the Court past majority. If child support was originally ordered by another state than Kansas, then the time that child support is required is determined by that state’s laws rather than the law of any state that may later modify any child support order.
As with all legal issues, you should set up an appointment with a qualified family lawyer to review the situation in your own case, rather than relying on any general statement of the law.