Child Support in Los Angeles County, California

Los Angeles County is the most populous county in the country, and its family courts and county child support agency handle an enormous number of support cases each year. If you live in Los Angeles, Long Beach, Santa Clarita, Glendale, Pomona, or any of the county's many other cities, a child support case runs through the Superior Court of California, County of Los Angeles, which accepts family law filings at a dozen courthouses across the county, including the Stanley Mosk Courthouse in downtown Los Angeles, and through the Los Angeles County Child Support Services Department (CSSD), the county's local child support agency.

California sets child support using a statewide uniform guideline formula (Family Code section 4055). The number is based mainly on both parents' net disposable incomes and the share of time the child spends with each parent, known as the timeshare. The guideline amount is presumed correct, and Los Angeles County applies the same formula as every other county.

Support can be set in two ways. Either parent can file a Request for Order (Form FL-300) with an Income and Expense Declaration (Form FL-150) inside a divorce, parentage, or custody case, or CSSD can open a case to establish and enforce support. The court's own family law pages note that child support issues may also be raised through an action initiated by CSSD, so a parent who does not want to start a court case alone can apply through the agency instead. Because Los Angeles County is so large, what varies locally is which family law courthouse and which CSSD office serve your area, not the formula or the forms.

Since your number depends on income and timeshare, it is worth estimating first. Our free California child support calculator gives you a starting figure, and parents who agree can submit a written stipulation for a judge to sign instead of going to a hearing.

How child support is calculated in California

California sets child support with a statewide uniform guideline (Family Code section 4055) that applies the same way in Los Angeles County as everywhere else. The formula is based mainly on two things:

1. Both parents' net disposable incomes.
2. The percentage of time the child spends with each parent (the timeshare).

The guideline amount is presumed to be correct, and courts use a calculator to run the numbers. Because the result depends on accurate income, the Income and Expense Declaration (Form FL-150) you file is what drives your number.

Where child support cases are handled in Los Angeles County

Child support in Los Angeles County is handled through the Superior Court of California, County of Los Angeles, and the county's Local Child Support Agency, which is part of the California Department of Child Support Services. There are two common paths:

1. Either parent files a Request for Order (Form FL-300) with an Income and Expense Declaration (Form FL-150) inside a divorce, parentage, or custody case.
2. The Local Child Support Agency opens a case to establish, collect, and enforce support, often at no cost to the parents.

Because courthouse and local agency office details change over time, confirm current details using the official California Courts court finder:

Find the Los Angeles County Superior Court (official California Courts finder)

Local notes for Los Angeles County

The Los Angeles Superior Court designates twelve courthouses for family law filings, so the correct filing location depends on where you and your child live. The Stanley Mosk Courthouse in downtown Los Angeles is the largest, and locations such as Long Beach, Pomona South, Pasadena, Torrance, Van Nuys East, and Chatsworth cover the rest of the county. Confirm your courthouse on the court's website before you file, and look up your nearest CSSD office through the agency's site.

One procedural detail is specific to Los Angeles: since November 15, 2021, the court has required electronic filing in family law cases for litigants represented by attorneys. Self-represented parents are exempt and may still file on paper. The court also runs a Self-Help Resource Center for self-represented litigants that helps parents complete Form FL-150 and understand court procedure, though staff cannot give legal advice about your specific circumstances. Because the guideline result is driven by the income you report, completing the Income and Expense Declaration accurately is the most important part of the process.

Child support in California generally lasts until the child turns 18, or 19 if the child remains a full-time high school student living at home and is not self-supporting. Either parent can request a modification when circumstances change, such as a change in income or in the parenting timeshare.

Official child support resources in Los Angeles County

Family law cases in Los Angeles County, including child support requests, are heard at twelve courthouses designated by the Superior Court of California, County of Los Angeles: the Stanley Mosk Courthouse, the Michael D. Antonovich Courthouse, and the Chatsworth, Compton, Long Beach, Pomona South, Pasadena, Torrance, Inglewood, Santa Monica, Van Nuys East, and Whittier courthouses. Which courthouse handles your case depends on where you live within the county.

The county's local child support agency is the Los Angeles County Child Support Services Department (CSSD), which operates offices across the county, including in Van Nuys, Commerce, Pomona, and the Antelope Valley. CSSD uses a two step process: you apply with the agency, and the agency then files the case that leads to an enforceable court order.

Since November 15, 2021, the court has mandated electronic filing of family law documents for litigants represented by attorneys; self-represented litigants are exempt and may file on paper. The court's Self-Help Resource Center for self-represented litigants offers guidance on family law forms and procedure for parents handling their own case.

• LA County Child Support Services Department: how the process works
• LA Superior Court: child support in family law cases
• LA Superior Court Self-Help Resource Center

Local details reviewed July 2026. Offices and locations can change, so confirm with the official sites above before you file.

Los Angeles County Child Support FAQs