Child support amounts are set by state law, not by a fixed national number

There is no single dollar amount for child support across the United States. Each state has its own formula, and the amount depends on the parents' income, the number of children, custody arrangement, and other factors specific to your state. A court or child support agency in your state calculates what one parent owes the other based on that state's guidelines.

The amount can range from under $100 per month to over $2,000 per month per child, depending entirely on the parents' earnings and your state's rules. Even two cases with identical incomes can result in different amounts if they are decided in different states.

Key Takeaways

  • Child support amounts are calculated using your state's formula, which weighs both parents' income, custody time, and the number of children.
  • Most states use either the income shares model or the percentage of income model, but the exact calculation differs by state.
  • A family court judge or your state's child support enforcement agency determines the amount through a court order or agreement.
  • You can request a modification if either parent's income changes significantly or custody arrangements change.
  • The amount is enforced through wage garnishment, tax intercept, or other collection methods if the paying parent does not pay voluntarily.

How states calculate child support amounts

Most states use one of two main models. The income shares model (used by about 40 states) combines both parents' income, determines a total child support obligation based on that combined income, then divides it between parents based on their percentage of the total income and custody time. The percentage of income model (used by some states) calculates support as a straight percentage of the paying parent's income—for example, 17% for one child, 25% for two children, 32% for three.

Your state's child support guidelines are published by your state's department of human services, child support enforcement office, or family court. You can find your state's specific formula by searching "[your state] child support guidelines" or by contacting your state's child support enforcement agency directly. The agency can tell you what information they need to calculate an amount for your situation.

What information affects the calculation

The paying parent's gross income is the starting point—this includes wages, self-employment income, bonuses, and sometimes rental income or investment returns. The receiving parent's income also matters in most states, because it reduces the amount the other parent must pay. If one parent has primary custody (the child lives with them most of the time), that affects the calculation in most formulas.

Other factors that can change the amount include the number of children, whether either parent pays for health insurance or childcare, overnight visitation time with the non-custodial parent, and extraordinary expenses like special education or medical needs. Some states also consider whether the paying parent has other children from other relationships. A few states cap the income used in the calculation—for example, only counting income up to $150,000 per year—so very high earners may not pay proportionally more.

How a child support order is created

Child support is set through a court order, usually during a divorce, custody case, or paternity case. If both parents agree on an amount, they can submit a written agreement to the court, and the judge typically approves it. If they disagree, the judge applies your state's guidelines and issues an order.

You do not have to go to court if you use your state's child support enforcement agency. Many states allow parents to request that the agency calculate and enforce support without a court case, though a court order still results. Contact your state's child support enforcement office (often part of the Department of Human Services or Attorney General's office) to learn whether you can do this in your state and what documents you need to provide.

Modifying child support when circumstances change

If the paying parent's income drops significantly, or if custody changes, either parent can request a modification of the order. Most states allow modification if there has been a substantial change in circumstances—often defined as a 10% to 20% change in income, though this varies by state. You file a motion with the court that issued the original order, or you can ask your state's child support enforcement agency to handle the modification request.

Modification takes time; it is not automatic when income changes. The paying parent must formally request it through the court or agency. If income drops but the parent does not request a modification, they are still legally obligated to pay the original amount until a new order is issued.

How child support is collected and enforced

If the paying parent pays voluntarily, the money goes directly to the receiving parent or through the state's child support payment system. If payment stops, the state can enforce the order through wage garnishment (taking money directly from paychecks), intercepting tax refunds, placing a lien on property, suspending a driver's license, or referring the case to the district attorney for contempt of court charges.

Your state's child support enforcement agency handles collection. You can contact them to report non-payment, and they will pursue enforcement at no cost to you. Some states also allow private collection through a family law attorney, though this costs money.

Frequently Asked Questions

Does child support end when the child turns 18?

In most states, yes—support ends at 18 or when the child graduates high school, whichever is later. Some states extend it to 19 or 21 if the child is still in high school or enrolled full-time in college. A few states have no age limit if the child has a disability. Check your state's law or ask your child support enforcement agency for the exact age of termination in your state.

Can child support be modified if the paying parent loses their job?

Yes, but only if you request it through the court or child support agency. Losing a job is usually considered a substantial change in circumstances. You must file a modification request; the obligation does not automatically decrease. If you wait months to request it, you may still owe back support for that period.

What if the paying parent lives in a different state?

The Uniform Interstate Family Support Act (UIFSA) allows your state to enforce an order against a parent in another state. Your state's child support enforcement agency can file paperwork with the other state's agency to pursue collection. This process takes longer than in-state enforcement but is available at no cost to you.

Is child support the same as custody or visitation?

No. Child support is a financial obligation; custody and visitation are about where the child lives and who spends time with them. A parent can owe child support even if they have no visitation, and a parent with equal custody time may still owe support if their income is significantly higher. These are separate legal issues.

Can I get child support if the parents were never married?

Yes. If paternity is established (either through a voluntary acknowledgment or a court order), child support can be ordered the same way as in a divorce. Your state's child support enforcement agency can help establish paternity and set support at the same time, usually at no cost.