Child support in California
California uses the income-shares model: both parents' incomes count, and each parent pays a share of the child's support. To open a case, contact the California Department of Child Support Services (DCSS) at 1-866-901-3212.
Checked against official sources: Oct 25, 2026. · Free letters and checklist ↓
How much child support in California?
California uses its own statewide formula based on both parents' monthly net income (after taxes and allowed deductions) and the share of time each parent has the children. Child care and uninsured health costs can be added and shared between the parents.
Law: Cal. Fam. Code 4050-4076 (statewide uniform guideline), as amended by SB 343 (Stats. 2023, ch. 213)
We don't estimate California's amount here: its formula uses both parents' incomes and other facts, and a home-made number could mislead you. The official tool gives the real starting number:
Open a child support case in California
- Agency
- California Department of Child Support Services (DCSS) and local child support agencies (LCSA)
- Phone
- 1-866-901-3212 (Customer Connect); TTY 1-866-399-4096
- Apply
- Apply online
- How to open a case
Enroll online with DCSS (about 10 minutes) or at your local child support agency. The LCSA asks the court for child and medical support orders at no cost to you; its attorney does not represent either parent and does not handle custody, visitation or divorce. You can also ask the court yourself, in an existing divorce or parentage case or by starting a new case.
- Application fee
$0. Either parent or a legal guardian can enroll, with or without a court order, and there are no income requirements. Services are free for the paying parent.
Source: DCSS FAQ
- Yearly fee
$35 a year on cases of a parent receiving support who does not get public cash assistance, when $550 or more was paid in the federal fiscal year. You get a fee notice in October for each case.
Source: DCSS FAQ
- Paternity (legal fatherhood)
Unmarried parents can establish legal parentage without court by both signing a Voluntary Declaration of Parentage (VDOP) and filing it with the state; there is a limited time to cancel it. Or either parent or the LCSA can start a parentage case, and the judge may order genetic testing.
California child support by topic
How support is calculated in California
The model, the percentages or the official calculator, and low-income rules.
Change child support in California
When you can ask, how to ask, and a review letter.
Collect unpaid support in California
Collection tools, interest and license rules, and a letter.
When support ends in California
The end age, high school and disability rules.
How child support is figured in California
- Model
- Income shares
- How it works
California uses its own statewide formula based on both parents' monthly net income (after taxes and allowed deductions) and the share of time each parent has the children. Child care and uninsured health costs can be added and shared between the parents.
- Low income
A low-income adjustment can lower support when the paying parent's net income is less than what a full-time minimum-wage job pays. Since January 1, 2026, courts must base orders on a parent's actual income or earning capacity using listed factors instead of a 'presumed income' figure.
Law: SB 343, effective September 1, 2024
- Official calculator
- Official California child support calculator
- Health insurance and medical costs
The LCSA asks the court for medical support in every case. Court-ordered health insurance must be used first. Uninsured health care costs are split as the order says: give the other parent an itemized bill within 90 days of getting it.
Source: Notice FL-192
Law: Cal. Fam. Code 4050-4076 (statewide uniform guideline), as amended by SB 343 (Stats. 2023, ch. 213)
Change a child support order in California
- When a change is allowed
When circumstances change, such as a big rise or drop in either parent's income or a change in custody or parenting time. California law sets no fixed percentage. A change can only go back to the date you filed your request, so file quickly.
- How to ask
If you disagree with the other parent, file a Request for Order (FL-300) with an Income and Expense Declaration (FL-150). If you agree, file a written agreement for the judge to sign. If an LCSA handles your case, ask the LCSA for a review or follow the LCSA court instructions; the LCSA must approve any agreement.
Law: Cal. Fam. Code 3651
Can I ask for a change? Check your situation
Collect unpaid child support in California
Arrears means support that is past due. The child support agency can use these tools to collect it:
- Collection tools
- Income withholding
- State and federal tax refund intercept
- Interception of unemployment, disability, workers' compensation, lottery winnings and insurance settlements
- Driver's, professional and recreational license suspension
- Passport denial
- Liens on property and bank accounts
- Credit bureau reporting
- Contempt of court
- License suspension
Payment more than 30 days overdue triggers a notice to licensing agencies; you get 150 days to respond the first time and 30 days the next time. A DMV driver's license is not suspended if your income is at or below 70% of your county's median income.
- Contempt of court
In extreme cases the court can find a parent in contempt, which can lead to arrest and jail, used only when other tools have failed (DCSS).
- Interest on unpaid support
10% a year on unpaid support.
Source: DCSS FAQ
When child support ends in California
- Support ends
18, or when the child graduates from high school or turns 19, whichever comes first, if the child is unmarried and still in high school full time
- Exceptions
Support can continue for an adult child who is disabled and cannot support himself or herself, or if the parents agree. Support also ends if the child marries, enters a domestic partnership, joins the military, is emancipated or dies.
Law: Cal. Fam. Code 3901, 3910
When does support end? Check your situation
Free help in California
Official self-help
Free letters and checklist
Ask the agency to review (change) your order
A letter to the child support agency asking for a review and adjustment.
Ask the agency to collect unpaid support
A letter asking the agency to enforce the order and collect what is past due.
Checklist: what to bring to open a case
IDs, birth certificates, the other parent's details and your papers, with California's agency contact.
Good to know in California
- A change in support can only start from the date you file your request, not from when your income changed (California Courts Self-Help).
- A DMV driver's license is protected from suspension if your income is at or below 70% of the county median (DCSS).
- Wage withholding does not stop by itself when the child turns 18; you need a court-signed Terminated Income Withholding Order (DCSS FAQ).
Changes in 2024–2026
SB 343: from September 1, 2024, updated income bands in the formula, a new low-income adjustment tied to full-time minimum wage, add-on costs shared by net income, and child care reimbursed only if actually paid; from January 1, 2026, 'presumed income' was replaced by earning capacity based on specific factors, with more ways to set aside default orders (Judicial Council of California, 2025 AB 1058 Conference).
Law: Stats. 2023, ch. 213
Federal rules in every state
- Applying. If you don't get TANF, Medicaid or foster care help, a state may charge an application fee of up to $25 to open a child support case. Law: 42 U.S.C. 654(6)(B)(i)
- Yearly fee. If you never got TANF and the agency collected at least $550 for you in a year, the state charges a $35 yearly fee. It can come out of your support, but never out of the first $550. Law: 42 U.S.C. 654(6)(B)(ii)
- Review every 3 years. If your case is with the child support agency, either parent can ask it to review the order every 3 years and adjust it to the guidelines. Law: 42 U.S.C. 666(a)(10)(A); 45 CFR 303.8
- Past-due support. Each unpaid payment becomes a judgment on the day it is due. It can't be lowered later, except back to the date the other parent got notice of a request to change the order. Law: 42 U.S.C. 666(a)(9)
- Tax refunds. The federal government can take a federal tax refund to pay past-due child support. Law: 42 U.S.C. 664
- Passports. A parent who owes more than $2,500 in past-due support can be refused a passport. Law: 42 U.S.C. 652(k)
- Pay withholding limit. For support, up to 50% of take-home pay can be withheld if the parent supports another spouse or child, or 60% if not. It is 55% or 65% when support is more than 12 weeks behind. Law: 15 U.S.C. 1673(b)
- How long support lasts. How long support lasts follows the law of the state that made the order, even if you move. Law: 28 U.S.C. 1738B(h)(2)
Questions about child support in California
How is child support calculated in California?
California uses its own statewide formula based on both parents' monthly net income (after taxes and allowed deductions) and the share of time each parent has the children. Child care and uninsured health costs can be added and shared between the parents.
Is there an official child support calculator for California?
What if the paying parent has a low income in California?
A low-income adjustment can lower support when the paying parent's net income is less than what a full-time minimum-wage job pays. Since January 1, 2026, courts must base orders on a parent's actual income or earning capacity using listed factors instead of a 'presumed income' figure.
How do I apply for child support in California?
Enroll online with DCSS (about 10 minutes) or at your local child support agency. The LCSA asks the court for child and medical support orders at no cost to you; its attorney does not represent either parent and does not handle custody, visitation or divorce. You can also ask the court yourself, in an existing divorce or parentage case or by starting a new case.
Does it cost money to open a child support case in California?
$0. Either parent or a legal guardian can enroll, with or without a court order, and there are no income requirements. Services are free for the paying parent.
Is there a yearly fee for child support services in California?
$35 a year on cases of a parent receiving support who does not get public cash assistance, when $550 or more was paid in the federal fiscal year. You get a fee notice in October for each case.
When can child support be changed in California?
When circumstances change, such as a big rise or drop in either parent's income or a change in custody or parenting time. California law sets no fixed percentage. A change can only go back to the date you filed your request, so file quickly.
How do I ask to change child support in California?
If you disagree with the other parent, file a Request for Order (FL-300) with an Income and Expense Declaration (FL-150). If you agree, file a written agreement for the judge to sign. If an LCSA handles your case, ask the LCSA for a review or follow the LCSA court instructions; the LCSA must approve any agreement.
What happens if child support is not paid in California?
Arrears means support that is past due. The child support agency can use these tools to collect it: Income withholding; State and federal tax refund intercept; Interception of unemployment, disability, workers' compensation, lottery winnings and insurance settlements; Driver's, professional and recreational license suspension; Passport denial; Liens on property and bank accounts; Credit bureau reporting; Contempt of court.
Can a license be suspended for unpaid child support in California?
Payment more than 30 days overdue triggers a notice to licensing agencies; you get 150 days to respond the first time and 30 days the next time. A DMV driver's license is not suspended if your income is at or below 70% of your county's median income.
Can a parent be held in contempt for not paying in California?
In extreme cases the court can find a parent in contempt, which can lead to arrest and jail, used only when other tools have failed (DCSS).
Is there interest on unpaid child support in California?
10% a year on unpaid support.
When does child support end in California?
18, or when the child graduates from high school or turns 19, whichever comes first, if the child is unmarried and still in high school full time
Does child support continue while my child finishes high school in California?
18, or when the child graduates from high school or turns 19, whichever comes first, if the child is unmarried and still in high school full time
Can child support continue past the usual age in California?
Support can continue for an adult child who is disabled and cannot support himself or herself, or if the parents agree. Support also ends if the child marries, enters a domestic partnership, joins the military, is emancipated or dies.
How is paternity established in California?
Unmarried parents can establish legal parentage without court by both signing a Voluntary Declaration of Parentage (VDOP) and filing it with the state; there is a limited time to cancel it. Or either parent or the LCSA can start a parentage case, and the judge may order genetic testing.
Who pays for the child's health insurance in California?
The LCSA asks the court for medical support in every case. Court-ordered health insurance must be used first. Uninsured health care costs are split as the order says: give the other parent an itemized bill within 90 days of getting it.
More help on our sister sites
Sources
- DCSS Frequently Asked Questions
- DCSS Enroll for Support
- DCSS License Suspension
- DCSS Contact Us
- DCSS Guideline Calculator
- California Courts Self-Help: Child support
- California Courts Self-Help: Ask for or change child support (LCSA)
- California Courts Self-Help: Parentage
- Judicial Council: Governmental Child Support After SB 343 (2025)
- Form FL-192 Notice of Rights and Responsibilities
Last checked: Oct 25, 2026.
- State plan requirements: application fee, annual fee, safeguards, 42 U.S.C. 654
- Required state laws: arrears as judgments, review every 3 years, UIFSA, 42 U.S.C. 666
- Federal tax refund offset, 42 U.S.C. 664
- Passport denial for child support arrears, 42 U.S.C. 652(k)
- Garnishment limits for support orders, 15 U.S.C. 1673(b)
- Full faith and credit for child support orders, 28 U.S.C. 1738B
- Office of Child Support Enforcement (federal)