How Child Support Is Calculated in California

California courts use a statewide guideline formula that looks at how much each parent earns, how they file taxes, how much time each spends with the children, and other factors. The Department of Child Support Services offers a free online guideline calculator. Support generally ends when the child turns 18 and has graduated high school, or turns 19 if still a full-time high school student, whichever comes first.

Enroll with California Child Support Services (the state Department of Child Support Services and local child support agencies) using the online enrollment form, or enroll in person. Either parent or a legal guardian can enroll, whether or not a court order exists, and there are no income or other eligibility requirements. Services include locating parents, establishing parentage, getting child and medical support orders, enforcing and modifying orders, and processing payments. Asking the court for orders through the agency is at no cost; a parent receiving support who has never received public cash assistance may be charged an annual federal fee of no more than $35, and services are free for the parent who pays.

Parents must support a child until 18. Support continues for an unmarried 18-year-old who is a full-time high school student and is not self-supporting, until the child finishes 12th grade or turns 19, whichever comes first; a child whose documented medical condition prevents full-time attendance is excused from the full-time requirement. Separately, each parent has an equal duty to support an adult child of any age who is incapacitated from earning a living and without sufficient means; the court may order that payment go into a special needs trust. Parents may also agree to provide more support.

A court may modify or end a support order at any time as it finds necessary, but not for amounts that came due before the request (notice of motion) was filed. Through the child support agency, either parent or a guardian with an open case can ask for a free review and adjustment; generally the order can be changed if it would go up or down by 20% or $50, whichever is less. Reasons to ask include job loss or a new job, income changes, custody or visitation changes, a change in family size, disability, incarceration, or military deployment. If the agency says no, you can still ask a judge, and the county Family Law Facilitator can help. A parent who will be incarcerated for 60 days or more can submit an Incarcerated Parent's Request to Review Child Support.

If support is not paid on time and in full, California Child Support Services says: unpaid balances are charged 10% interest per year; state and federal tax refunds, unemployment, workers' compensation, state disability benefits, lottery winnings and insurance settlements can be intercepted; wages and other income can be withheld; driver's licenses (for parents whose income is above 70% of the county median) and professional licenses can be suspended; liens can be placed on property and bank accounts and bank accounts can be levied; passports can be denied; the debt can be reported to credit bureaus; and in extreme cases a court can find the parent in contempt, which can lead to arrest.

California Child Support Services (the state Department of Child Support Services, working through local child support agencies) helps parents and legal guardians establish legal parentage, locate the other parent, get child and medical support orders, change orders when they qualify, and collect, send and track payments. It does not handle custody or visitation, divorces, restraining orders or spousal support. Enroll through the online form at childsupport.ca.gov/enroll; pay through the State Disbursement Unit; view case information through Customer Connect. Automated line: 1-866-901-3212 (TTY 1-866-399-4096; outside the U.S. 1-408-273-0073).

California Child Support Services (the state Department of Child Support Services) publishes the California Child Support Guideline Calculator. The page says it "provides only an estimate and is not a guarantee of the amount of support that will be ordered," and that the county child support commissioner or family law judge has the final authority over the amount of a support order.