Arizona uses a formula based on both parents' income, not a fixed dollar amount

Arizona does not have a single child support number that applies to everyone. Instead, the state uses a income shares model, which means the court calculates what percentage of each parent's income should go toward child support, then divides that obligation between them based on their earnings. A parent earning $3,000 a month will owe a different amount than a parent earning $6,000 a month, and the amount changes if either parent's income changes.

The calculation starts with each parent's gross monthly income — wages, self-employment earnings, bonuses, rental income, and some benefits all count. The court then applies the state's child support guidelines, which are percentages set by Arizona law. For one child, the guideline is roughly 12% of combined parental income. For two children, it is roughly 19%. For three children, roughly 22%. For four children, roughly 24%. For five or more children, roughly 25%.

Once the court knows the total obligation, it splits that amount between the parents based on what percentage of the combined income each one earns. If one parent earns 60% of the total and the other earns 40%, the parent earning 60% pays 60% of the child support obligation. The parent with primary custody usually receives the payment, though both parents are considered to have a duty to support the child.

Key Takeaways

  • Arizona calculates child support as a percentage of both parents' combined gross income, not a flat amount, so the number depends entirely on what each parent earns.
  • The guideline percentages range from 12% of combined income for one child to 25% for five or more children, and the court splits this obligation between parents based on their income ratio.
  • Gross income includes wages, self-employment earnings, bonuses, rental income, and certain benefits, but the court can add or subtract amounts based on other factors like custody time and existing support orders.
  • The amount can be modified if either parent's income changes by 10% or more, or if custody arrangements change significantly.
  • Arizona courts can adjust the guideline amount upward or downward based on factors like the number of overnights each parent has, health insurance costs, and childcare expenses.

What counts as income for child support purposes

The court looks at gross income, which means income before taxes are taken out. This includes W-2 wages from employment, self-employment income, bonuses, commissions, rental income, interest and dividend income, and income from pensions or annuities. It also includes certain government benefits like unemployment compensation and workers' compensation, though not Supplemental Security Income (SSI) or Temporary Assistance for Needy Families (TANF).

If a parent is voluntarily unemployed or underemployed — meaning they could earn more but choose not to — the court may assign them "imputed income" based on what they could reasonably earn. This prevents a parent from lowering their support obligation by quitting a job or working part-time. However, the court must have evidence that the underemployment is voluntary; a parent who loses a job through no fault of their own is not penalized.

The court can also exclude certain income or add back certain deductions. For example, if a parent is already paying child support or spousal maintenance for another child or former spouse, that amount is subtracted from their gross income before the guideline calculation. Income from a new spouse or partner is not counted.

How the court adjusts the guideline amount

Arizona law sets the percentages, but the court has authority to adjust the amount up or down based on specific circumstances. One of the most common adjustments involves parenting time. If the parent paying support has the child overnight more than 30% of the time (roughly 110 nights per year), the guideline amount is reduced. The more overnights, the larger the reduction, because that parent is directly covering some expenses while the child is in their care.

The court also adjusts for childcare costs and health insurance premiums. If one parent pays for daycare or preschool so the other parent can work, that cost is added to the child support obligation and split between the parents. If one parent carries the health insurance for the child, that premium is also factored in. These adjustments can raise or lower the final amount significantly.

Other reasons the court may deviate from the guideline include: the child has special needs or extraordinary expenses; one parent has significantly more wealth than the other; the child is in private school; or the combined parental income is very high or very low. The court must document in writing why it is deviating and by how much.

Income limits and high-income cases

Arizona's child support guidelines apply up to a combined parental income of $30,000 per month (as of 2024, though this figure is adjusted periodically). If both parents together earn more than this, the court calculates the guideline amount on the first $30,000, then has discretion to order additional support based on the factors listed above — the child's needs, the parents' standard of living, and other circumstances.

In high-income cases, the court often orders support well above the guideline percentage because the child may have been accustomed to a higher standard of living. A child whose parents earn $100,000 per month combined may have expenses — private school, tutoring, travel, activities — that require support far exceeding the 12% to 25% guideline. The court considers what the child would have received if the parents had remained together.

There is no minimum income threshold in Arizona. Even if a parent earns very little, they may still owe child support, though the amount will be small. The court can also order support from a parent who is not currently working, by imputing income based on their earning capacity.

Temporary support versus final orders

During a divorce or custody case, the court may order temporary child support while the case is pending. This is calculated the same way as final support — using the income shares model and the guideline percentages — but it ends when the final order is entered. Temporary support gives the custodial parent money to cover expenses while the case is ongoing, which can take months or years.

The final child support order is entered as part of the divorce decree or custody order. Once entered, it remains in effect until the child turns 18, graduates from high school (whichever is later), or the court modifies it. If the child is still in high school after turning 18, support continues until graduation or age 19, whichever comes first.

Modifying child support when circumstances change

Child support can be modified if there is a substantial and continuing change in circumstances. In Arizona, a change in either parent's income of 10% or more usually qualifies. A significant change in parenting time — such as one parent moving away or the custody arrangement shifting — also justifies modification. A parent can request modification through the court that issued the original order, or through the state's child support enforcement agency.

The modification process requires filing a petition with the court and serving the other parent. The court will recalculate support based on current income and circumstances. If the new amount is significantly different from the current order, the court may order the change to take effect immediately or phase it in over a few months. Back support (support owed from the date the modification was requested) is typically owed only from the date the petition was filed, not retroactively.

If a parent's income drops due to job loss, illness, or other hardship, they should request modification promptly. Waiting to file does not stop the obligation to pay the current amount, and arrears (unpaid support) can accumulate quickly. The court will not retroactively reduce support unless there was a substantial reason for the delay in filing.

How support is collected and enforced

Child support is usually collected through income withholding, which means the paying parent's employer deducts the support amount from their paycheck and sends it to the state. The state then forwards it to the receiving parent. This is automatic in most cases and does not require the receiving parent to take action.

If the paying parent is self-employed or does not have a regular employer, they may be ordered to pay directly to the state's clearinghouse or to the receiving parent. The court can also place a lien on property, intercept tax refunds, suspend a driver's license, or hold the parent in contempt of court if support is not paid.

Arizona's Department of Child Support Services handles enforcement for cases where the state is involved (usually when the custodial parent receives TANF or other public benefits). Private enforcement is also possible — the receiving parent can hire an attorney to pursue collection. Either way, unpaid support accrues interest and can result in serious legal consequences for the paying parent.

Frequently Asked Questions

Does child support end when the child turns 18?

Support ends when the child turns 18 or graduates from high school, whichever is later. If the child is still in high school after turning 18, support continues until graduation or age 19, whichever comes first. Support does not continue into college unless the parents agree to it or the court orders it as part of the original decree.

Can I get child support modified if I lost my job?

Yes. Job loss is a substantial change in circumstances that justifies modification. You should file a petition to modify as soon as possible after losing employment. The court will recalculate based on your current income or imputed income if you are not actively searching for work. You remain obligated to pay the current amount until the modification is approved.

What if the other parent is not paying child support?

Contact the Arizona Department of Child Support Services or hire a private attorney. The state can enforce through income withholding, tax intercept, license suspension, and contempt proceedings. If you are receiving TANF or other public benefits, enforcement is automatic. Unpaid support accrues interest and does not disappear — it can be collected years later.

Can I deduct child support from my taxes?

No. The paying parent cannot deduct child support payments from their income taxes. The receiving parent does not report child support as taxable income. This is different from spousal maintenance (alimony), which has different tax treatment.

What if both parents have equal custody time?

Even with equal custody, one parent usually pays support to the other based on income difference. If both parents have the child 50% of the time and earn the same income, support may be minimal or zero. The court calculates the guideline obligation first, then reduces it based on the 50/50 parenting time split.