Your rights
How does child support work, and how is it calculated?
Key points
- Amount
- Every state must have child support guidelines. The amount they produce is presumed correct, and a judge needs a written reason to order something different.
- Where to start
- Your state or tribal child support agency can find the other parent, establish paternity, get an order, collect it and review it.
- Changes
- Ask for a change as soon as your situation changes. Past-due support generally can't be reduced for the time before you asked.
- Enforcement
- Unpaid support can be taken from paychecks and tax refunds, and can lead to suspended licenses and, above $2,500 owed, a denied passport.
Child support is set and enforced by the states, inside a federal framework. Federal law requires every state to have guidelines for the amount, to offer child support services to anyone who applies, and to use tools such as paycheck withholding to collect it. The formula itself, and the rules for changing an order, differ from state to state.
Below: how the amount is set, how to apply for help from your state agency, establishing paternity, changing an order, what happens when support isn't paid, cases across state lines, what to do if you can't pay, and a side-by-side comparison of California, Texas, Florida and New York, each with its official sources.
Who pays child support, and how the amount is set
A child support order legally requires a parent to help pay to raise a child. Federal child support law generally calls the parent who owes support the noncustodial parent. Federal and state governments do not pay child support themselves; they help families collect it from a parent.
- Every state has guidelines. Federal law requires each state to set guidelines for child support amounts, make them available to the judges and officials who decide support, and review them at least once every 4 years.42 U.S.C. § 667(a), (b)(1)
- The guideline amount is presumed correct. In any court or agency case, the amount the guidelines produce is presumed to be the right one. A different amount needs a written finding, or a specific finding on the record, that the guideline amount would be unjust or inappropriate.42 U.S.C. § 667(b)(2)
- Each state uses its own formula. Some look only at the paying parent's income, as Texas does. Others start from both parents' incomes, as California, Florida and New York do. See the state comparison below.Tex. Fam. Code § 154.125 · California Courts · Fla. Stat. § 61.30 · N.Y. Dom. Rel. Law § 240(1-b)
How to get child support: help from your state agency
Start with your state or tribal child support agency, wherever the other parent lives. Federal law requires every state to provide child support services for any child when someone applies for them. The agency can help with:
- Finding the other parent.
- Establishing legal parentage (paternity).
- Getting a support order, including medical support such as health insurance for the child.
- Enforcing the order and collecting payments.
- Reviewing the order and changing it when it qualifies.
- California. Either parent, or a legal guardian, can enroll whether or not a court order exists, and there are no income or other eligibility requirements. You can enroll online, and the agency can get a court order at no cost.California Department of Child Support Services
- Texas. The Child Support Division of the Office of the Attorney General is the state's official child support agency, with field offices that help establish paternity and enforce orders.Texas State Law Library
- Florida. The Department of Revenue runs the program, and its services are available on behalf of all dependent children. The federally required application fee is $1, and the department waives it and pays it itself.Fla. Stat. §§ 409.2554(5), 409.2557(1), 409.2567(1)(a)
Establishing paternity
A support order needs a legal parent. In California, for example, if there is no court order yet, the support agency will locate the other parent and establish legal parentage if needed. Federal law requires every state to have these procedures:
- Any time before the child turns 18. States must allow paternity to be established at any time before the child turns 18.42 U.S.C. § 666(a)(5)(A)
- A voluntary acknowledgment. Parents can sign an acknowledgment of paternity through a simple civil process. Before signing, both must be told, orally and in writing, about the alternatives, the legal consequences and the rights and responsibilities that come with it.42 U.S.C. § 666(a)(5)(C)(i)
- Signing has legal weight. A signed acknowledgment counts as a legal finding of paternity, subject to the right to cancel it within 60 days, or by the date of an earlier court or agency proceeding about the child in which the signer is a party.42 U.S.C. § 666(a)(5)(D)(ii)
- Genetic testing when it is contested. In a contested paternity case, states must require the child and the other parties to take genetic tests when a party asks with a sworn statement supporting the request, unless state law bars it.42 U.S.C. § 666(a)(5)(B)
In Texas, the mother and a man claiming to be the biological father may sign an acknowledgment of paternity with the intent to establish his paternity. For custody orders between parents who never married, see Child custody.
Changing (modifying) a child support order
A support order can go up or down when circumstances change. You can ask the court, or, if the agency handles your case, ask the agency for a review.
- A review every 3 years, on request. In cases the agency handles, either parent can ask for a review every 3 years, or more often if the state allows, and the order is adjusted if appropriate. Between those reviews, the parent asking must show a substantial change in circumstances. The state must remind parents of this right at least once every 3 years.42 U.S.C. § 666(a)(10)
- Changes don't reach back. Each payment becomes a judgment on the date it is due and can't be changed retroactively, except back to the date the other parent was notified of a request to change it.42 U.S.C. § 666(a)(9)
- California: ask the local child support agency for a free review and adjustment, or file a Request for Order (form FL-300) with an Income and Expense Declaration (form FL-150). The agency lists reasons to ask, such as losing your job, an income change, a custody change, going to jail or prison, or military deployment, and says a change can generally happen if the order would change by 20% or $50, whichever is less.
- Texas: a court can modify support if circumstances have materially and substantially changed, or if it has been 3 years and the amount differs from the guidelines by 20 percent or $100. A change applies only to support due after the other parent is served or appears in the case.
- Florida: either parent can ask the court to increase or decrease support when circumstances or financial ability change. A difference from the guidelines of at least 15 percent or $50, whichever is greater, can show a substantial change. The court can make a change apply back to the date the request was filed.
- New York: a court can modify support on a substantial change in circumstances, or, unless the parents opted out in their agreement, when 3 years have passed or either parent's gross income has changed by 15 percent or more.
What happens if child support isn't paid
Federal law gives every state a set of collection tools. The most common is income withholding: the payments come straight out of the paying parent's paycheck. New orders generally include immediate withholding unless a court finds good cause not to, or both parents agree in writing to another arrangement. In California, orders most often include a wage and earnings assignment, and the employer sends the money to the State Disbursement Unit, which sends it to the other parent.
When support goes unpaid, states can also:
- Take the money from federal tax refunds, through the U.S. Treasury, and from state income tax refunds.
- Place liens on real and personal property for overdue support.
- Report the parent and the amount overdue to credit reporting agencies.
- Withhold, suspend or restrict driver's, professional, occupational and recreational licenses.
- Certify the debt so that the State Department refuses a passport when more than $2,500 is owed, and it may revoke or restrict an existing passport.
When parents live in different states: UIFSA
Every state must have the Uniform Interstate Family Support Act (UIFSA) in effect. It decides which state's order controls and which state can change it, and it lets orders be enforced across state lines. Your own state's agency can still help you get, change or enforce an order, wherever the other parent lives, and the federal Office of Child Support Services can give more help with a case in another state.
- The state that made the order usually keeps it. A state that issued the controlling order keeps the exclusive power to change it while the paying parent, the parent receiving support or the child still lives there, or if the parents agree it should.Tex. Fam. Code § 159.205
- Paycheck withholding works across state lines. An income withholding order from another state can be sent straight to the paying parent's employer, without first filing a case in the employer's state.Tex. Fam. Code § 159.501
- Orders can be registered in a new state. A support order from another state can be registered in the new state so its courts can enforce it.Tex. Fam. Code § 159.601
California's child support agency notes that once you have an order, it can be enforced in every state and many foreign countries.
What to do if you can't pay child support
- Ask for a change right away. Lost your job, earning less, or going to jail or prison? Ask the agency for a review or file a request with the court now. Support that comes due before you ask generally can't be reduced later.
- Keep records and gather proof. California's agency asks for proof of your income and expenses, child care and medical insurance costs, any disability, jail or prison status and unemployment benefits.
- Pay what the order says until it changes. Each missed payment becomes a judgment when it is due, and in California unpaid support collects interest.
- Ask about debt programs. California's Debt Reduction Program can lower child support debt owed to the government, which arises when the children received cash aid or were in foster care. It does not reduce support owed directly to the other parent, or change current monthly support.
- Jail or prison. In Texas, incarceration for more than 180 days is a material and substantial change in circumstances. In New York, incarceration is not considered voluntary unemployment.Tex. Fam. Code § 156.401(c-1) · N.Y. Fam. Ct. Act § 451(3)(a)
- Losing your job. In New York, a drop in income counts toward a change only if it was involuntary and you have made diligent efforts to find work that matches your education, ability and experience.N.Y. Fam. Ct. Act § 451(3)(b)
Child support in California, Texas, Florida and New York
| State | Who runs the program | How the guideline works | When an order can change |
|---|---|---|---|
| California | The local child support agency, in some counties called the Department of Child Support Services. Either parent or a guardian can enroll. California Courts · childsupport.ca.gov | Looks at how much each parent makes, how they file taxes and how much time each spends with the children. California Courts | When circumstances change, such as a job loss or custody change; only back to the date you filed. California Courts |
| Texas | The Attorney General's Child Support Division. Texas State Law Library | A share of the paying parent's monthly net resources: 20% for 1 child, 25% for 2, 30% for 3, 35% for 4, 40% for 5 or more, with lower rates under $1,000 a month. Fam. Code § 154.125 | A material and substantial change, or 3 years and a 20% or $100 gap from the guidelines. Fam. Code § 156.401 |
| Florida | The Department of Revenue. Fla. Stat. § 409.2557 | Both parents' net incomes are combined, a schedule sets the child support need, and each parent pays a share in proportion to income. Fla. Stat. § 61.30 | When circumstances or financial ability change; a gap from the guidelines of 15% or $50, whichever is greater, can show it. Fla. Stat. §§ 61.14, 61.30 |
| New York | The court sets support under the child support standards in Domestic Relations Law § 240. nysenate.gov | Combined parental income, up to a cap, times 17% for 1 child, 25% for 2, 29% for 3, 31% for 4, at least 35% for 5 or more, shared in proportion to income. Dom. Rel. Law § 240(1-b) | A substantial change, 3 years, or a 15% change in either parent's gross income. Fam. Ct. Act § 451 |
Florida also adjusts support when a parent has the children for at least 20 percent of the overnights in a year, and a judge who orders an amount more than 5 percent away from the guideline must explain why in writing. Other states have their own formulas: start with your state child support agency or your state court's self-help website.
Do I need a child support lawyer?
Not always. The state agency can get and enforce an order for you, and in California free help is available in every county: the family law facilitator can give information, help you calculate guideline support and help you fill out forms.
Keep in mind whom the agency's lawyers work for. In Florida, for example, the law says the attorney-client relationship in these cases exists only between the department and its legal services providers, not with either parent. Talk to a child support lawyer or legal aid if the other parent has a lawyer, income is hard to prove (for example self-employment), you are asking for an amount different from the guidelines, the case involves another state or country, or there is family violence.
Common questions
How is child support calculated?
By your state's guidelines, which federal law requires every state to have. Some states use only the paying parent's income, as Texas does; others combine both parents' incomes and split the amount in proportion, as Florida and New York do. The guideline amount is presumed correct unless a judge finds in writing that it would be unjust or inappropriate.
How does child support work in Texas?
The Attorney General's Child Support Division is the state agency. Courts presumptively apply a share of the paying parent's monthly net resources: 20% for one child, 25% for two, 30% for three, 35% for four and 40% for five or more, with lower rates under $1,000 a month and a cap the state adjusts for inflation. An order can change after a material and substantial change, or after 3 years if it differs from the guidelines by 20% or $100.
How does child support find the other parent?
Finding the parent is one of the services your state or tribal child support agency provides. In California, for example, the agency will locate the other parent and establish legal parentage if needed. Start with your own state's agency even if the other parent lives elsewhere.
How does child support work if the parent with custody is unemployed?
It depends on the state's formula. In California, Florida and New York, the guideline looks at both parents' incomes, so the receiving parent's income can affect the amount. In Texas, the guideline percentages apply to the paying parent's net resources. Either parent can ask for a review when income changes.
Can I pay child support online?
Often the payments are taken straight from the paycheck. In California the employer sends them to the State Disbursement Unit, which sends them to the other parent; without a withholding order, check what your order says about how to pay. Ask your state's child support agency which payment options it offers.
Do I need a lawyer for child support?
Not always: the state agency can get and enforce an order, and courts offer free self-help. The agency's lawyers may not represent you (in Florida they work for the department), so talk to a lawyer or legal aid if the other parent has one, income is hard to prove, or another state is involved. See Find a lawyer or free legal aid.
Official sources
- USAGov: How to get help collecting child support (state and tribal agencies, interstate help from OCSS) usa.gov
- 42 U.S.C. § 667: State guidelines for child support awards govinfo.gov
- 42 U.S.C. § 654: State plan for child support services (services on application, application fee) govinfo.gov
- 42 U.S.C. § 666: Required state procedures (withholding, paternity, review, liens, credit reporting, licenses, UIFSA) govinfo.gov
- 42 U.S.C. § 664: Collection of past-due support from federal tax refunds govinfo.gov
- 42 U.S.C. § 652(k): Denial of passports for child support arrears govinfo.gov
- U.S. Department of Labor, Fact Sheet #30: Federal wage garnishment law (limits for child support) dol.gov
- California Courts Self-Help Guide: Child support (guideline, changing an order, free help) courts.ca.gov
- California Courts Self-Help Guide: How to pay child support (income withholding, interest) courts.ca.gov
- California Courts Self-Help Guide: Ask for or change a child support order (forms FL-300, FL-150) courts.ca.gov
- California Department of Child Support Services: How child support services work childsupport.ca.gov
- California Department of Child Support Services: Enroll for support childsupport.ca.gov
- California Department of Child Support Services: Request a modification (review and adjustment) childsupport.ca.gov
- California Department of Child Support Services: Debt Reduction Program childsupport.ca.gov
- Texas State Law Library: Child support (the Attorney General's Child Support Division, family violence) sll.texas.gov
- Texas Family Code, Chapter 154: child support guidelines (§ 154.125) legis.texas.gov
- Texas Family Code, Chapter 156: modification of child support (§ 156.401) legis.texas.gov
- Texas Family Code, Chapter 159: Uniform Interstate Family Support Act (§§ 159.205, 159.501, 159.601) legis.texas.gov
- Texas Family Code, Chapter 160: acknowledgment of paternity (§ 160.301) legis.texas.gov
- Florida Statutes § 61.30 (2026): child support guidelines flsenate.gov
- Florida Statutes § 61.14 (2026): modification of support flsenate.gov
- Florida Statutes § 409.2554 (2026): definitions (the Department of Revenue) flsenate.gov
- Florida Statutes § 409.2557 (2026): state agency for the child support program flsenate.gov
- Florida Statutes § 409.2567 (2026): services for all dependent children, application fee flsenate.gov
- New York Domestic Relations Law § 240(1-b): Child Support Standards Act nysenate.gov
- New York Family Court Act § 451: modification of child support orders nysenate.gov
- Child Welfare Information Gateway (HHS): Find help with a personal situation (domestic violence hotline) childwelfare.gov
Related
This page explains the law in general terms. It is not legal advice about your situation. Justice is not a law firm and is not affiliated with any court or government agency.