Child support is set by guidelines in every state. The formulas differ, but they share a logic: children should receive a share of their parents' combined income comparable to what they'd get if the household were intact.
The three main models
- Income shares (most states): both parents' incomes are combined, a table sets the support amount for that combined income and number of children, and each parent is responsible for a proportionate share. The non-custodial parent pays their share to the custodial parent.
- Percentage of income: support is a set percentage of the paying parent's income, sometimes adjusted for the other parent's income.
- Melson formula (a few states): a variation that reserves a self-support amount for each parent first.
What counts as income
Usually wages, salary, bonuses, commissions, self-employment income, rental income, pensions, unemployment and disability benefits. Courts can "impute" income to a parent who is voluntarily unemployed or underemployed, based on what they could earn.
Adjustments
- Parenting time: many states reduce support as the paying parent's overnights increase past a threshold.
- Health insurance premiums and unreimbursed medical costs
- Child care costs related to work
- Support for other children
- Extraordinary expenses: special needs, private school by agreement, extracurriculars
Deviations
Courts can depart from the guideline amount when applying it would be unjust, for example, very high incomes, a child's special needs, or a shared-custody arrangement the formula handles poorly. Deviations must be explained in the order.
Modifying support
Support can be modified when circumstances change substantially, job loss, a significant raise, a change in the parenting schedule, or a child's changing needs. The change is not automatic; you must file. Arrears generally can't be reduced retroactively, so file promptly if your income drops.
Enforcement
State child support agencies can garnish wages, intercept tax refunds, suspend licenses and report to credit bureaus. If you can't pay, seek a modification rather than simply stopping.
Most states publish an online support calculator. It's a useful estimate, not a substitute for advice. This article is general information.
Documents to gather before support is set
Guidelines are only as accurate as the numbers fed into them. Whether you'll pay or receive support, complete records make the calculation fairer.
- Federal and state tax returns for the last two to three years, with all schedules
- Recent pay stubs showing year-to-date earnings, overtime and bonuses
- W-2s, 1099s and records of any side income
- For self-employment: profit and loss statements, bank statements and business tax returns
- Proof of health insurance premiums and the portion attributable to the children
- Receipts or statements for work-related child care
- Records of unreimbursed medical, dental and therapy costs
- Orders or proof of support for other children
- A calendar showing actual overnights with each parent
Many courts require a sworn financial statement from each parent, so these documents do double duty. Ask for the other parent's records too, through the formal exchange process if needed. If you suspect income isn't being reported, your attorney can explain how to request more detail. Keep dated copies of everything you submit; you'll need them again if either of you later seeks a modification.
When income is hard to pin down
Guideline math is simple for someone with a steady salary. It gets harder when earnings move around or come from a business.
Commissions, bonuses and overtime often vary from year to year. Courts in many states handle this by averaging income over a period, commonly a few years, or by setting a base amount plus a share of any bonus actually received. If your pay fluctuates, bring records that show the pattern over time, not just your best or worst year.
Self-employment raises different questions. Business deductions that are fine for tax purposes aren't always accepted for support. A court may add back expenses that mainly benefit the owner personally, such as a vehicle used mostly for family errands or meals that weren't truly business-related.
Cash income and informal work are hard to prove directly, so courts look at lifestyle evidence: deposits, spending and assets that don't match reported earnings.
On the other side, a parent who quits a job or takes a lower-paying one without good reason may have income imputed. That means support is based on what they could reasonably earn given their work history, skills and the local job market.
A realistic example
Consider a hypothetical: Marcus pays support under an order based on his salary as a warehouse supervisor. Then his employer closes the facility, and he's laid off.
He's tempted to just pay less until he finds new work. Instead, he files a request to modify support within two weeks, attaching his layoff notice and his unemployment benefit statement. He knows that in many states a modification can't reach back earlier than the date the request was filed, so every week of delay could leave him owing the full amount.
While the request is pending, he pays what he can and saves proof of each payment. He also keeps a job search log, expecting the court to ask about his efforts.
Three months later he takes a new job paying an illustrative $8,000 a year less. He sends the court his new pay stubs. The judge now has current, documented numbers to run through the guidelines.
Common questions
At what age does child support stop?
It depends on your state. In many states, support ends when a child turns 18 or finishes high school, whichever comes later, within limits. Some states extend it to 19 or 21, and a few allow orders for college expenses. Support for an adult child with a disability may continue much longer. Your order usually states the end date or event.
Does a new spouse's income count toward child support?
Usually not directly. Guideline calculations generally rely on the parents' own incomes, and a stepparent has no legal duty to support someone else's child. Some states allow a court to consider a new spouse's income indirectly, for instance if it frees up the parent's own money or supports a deviation. How it's treated varies by state, so check your local rules.
Can parents agree to a different amount of child support?
Parents can often propose their own amount, but a judge typically has to approve it. Because support belongs to the child, courts generally won't accept an agreement that waives support entirely or falls well below the guidelines without a good reason. If you agree on a different figure, be ready to explain why it serves the child and get it into a court order.
Pay support through the official channel your order names, not in cash, so every payment leaves a record.
