Generally, in Missouri child support terminates when a child dies, marries, enters the military, becomes self supporting, or turns 18. However, child support can continue after age 18, and all the way to age 21, if the following requirements are met:

If the child is enrolled in and attending high school when he or she turns 18, then child support will continue through the completion of the high school program or age 21, whichever first occurs.

If the child is enrolls in an institution of vocational or higher education (college) by October 1 following graduation from high school (or completion of a GED program), the obligation for child support can continue until the child completes the program or turns 21, whichever occurs first. However, the child must enroll for and complete (pass) at least twelve hours of credit each semester, not including the summer semester, and achieve grades sufficient to re enroll.  The credit hour requirement is reduced to 9 if the child is employed and working at least 15 hours per week.

To remain eligible for continued child support, at the beginning of each semester the child must submit to each parent a transcript which includes the courses enrolled in and completed for each term, the grades and credits received for each such course, and an official document from the institution listing the courses which the child is enrolled in for the upcoming term and the number of credits for each such course. If the child fails to comply with this requirement, the paying parent can motion the court for an abatement (temporary termination) for the particular semester. However, if the non-custodial parent makes a formal request for the required documents, the child must produce them within 30 days or the child support can be permanently terminated.  Also, either parent or the child can ask the court for support to be paid directly to the child.

Under the law, an "institution of vocational education" means any post-secondary training or schooling for which the student is assessed a fee and attends classes regularly. "Higher education" means any community college, college, or university at which the child attends classes regularly.

Note that a modification or termination of child support under any of the above scenarios is not automatic, and the parent wishing to modify or terminate must do so by filing a motion with the Court.