In California, child support ends when the child reaches age 18, or 19 if the child is still in school.
Normally the non-custodial parent pays a child support order through a wage garnishment, which does not have a termination date because the court does not know when the child will graduate from high school. Theoretically, if a child progresses through school at a normal rate, the child (now a teenager) graduates from high school around May of her 18th birthday. However, some children have to redo grades or are held back, finishing high school a year later. The teenager may have dropped out of traditional high school and be enrolled in a non-traditional high school, online classes, or vocational/technical training.
The non-custodial parent may be estranged from the custodial parent and the teenager, and the non-custodial parent may not actually know if or when the teenager graduated from high school. As more and more people move around the country, often a custodial parent and the teenager are living in another city and state.
Because the non-custodial parent is paying child support under an order that normally has no termination on its face, the non-custodial parent has to coordinate with the custodial parent the stop child support payment date. It the non-custodial parents and custodial parents are communicating; the parties can agree to the end date and enter a written agreement (stipulation) with the court and obtain a court order that terminates the wage garnishment at the non-custodial parent’s employment.
However, if the custodial parent will not communicate with the non-custodial parent, the non-custodial parent is left with no choice but to see an emergency order through what is called an Ex-Parte hearing or through a noticed motion to obtain a court order to terminate the wage garnishment.
Unfortunately, the burden to terminate child support paid via wage garnishment falls on the non-custodial payor.
The non-custodial parent should ask the family court to put an end date to the child support obligation especially if the child support order is issued at the time the child has already entered high school. This would put the burden on the custodial parent to contact the non-custodial parent or to go back to family court if for some reason the child is NOT on track to graduate from high school in the anticipated normal time.