Arizona Child Support Calculator

Arizona calculates child support under the Arizona Child Support Guidelines, which were adopted pursuant to Arizona Revised Statutes section 25-320 and the corresponding Supreme Court Rule 88. The state uses the Income Shares model, under which the court combines both parents' monthly gross incomes to determine the basic support obligation from the guideline schedule. The schedule represents what parents at that combined income level would typically have spent on the child had they remained together, distributing the obligation proportionally between the two households.

Each parent's share of the combined obligation is determined by dividing their individual monthly gross income by the combined gross income of both parents. The parent who does not have primary physical custody — or the parent designated as the obligor under the parenting plan — pays their proportional share to the other parent as a monthly transfer payment. Courts are required to follow the guideline amount as a rebuttable presumption, meaning it applies automatically unless a party produces evidence and the court makes findings justifying a different amount.

The Arizona guidelines are reviewed at least every four years by the Supreme Court's Child Support Working Group, as required by federal law. These reviews examine economic data on child-rearing costs and may result in schedule adjustments. Arizona courts applying the guidelines must use the version in effect at the time the order is entered. Parties seeking to modify an existing order will have any new guideline tables applied to determine whether the current amount remains appropriate.

Arizona's guidelines define gross income broadly to include income from any source: wages, salary, overtime, commissions, bonuses, tips, self-employment earnings, pension and retirement income, disability payments, Social Security benefits, interest, dividends, rental income, and trust distributions. The comprehensive definition prevents a parent from artificially reducing the income figure by restructuring compensation or by receiving income in non-traditional forms.

Arizona further adjusts each parent's income by subtracting documented child support paid for other children from prior relationships, as well as spousal maintenance paid to a prior spouse, before combining the incomes for the guideline calculation. This adjustment ensures that existing legal obligations to other children are not ignored when setting support for the current child. The resulting figure is called each parent's adjusted gross income, and the sum of both parents' adjusted gross incomes is the combined adjusted gross income that drives the guideline schedule lookup.

For parents who are voluntarily unemployed or underemployed, Arizona courts may impute income based on the parent's earning capacity rather than actual reported income. Earning capacity is determined by looking at the parent's employment history, education level, occupational qualifications, and prevailing wages in the local labor market for work the parent is qualified to perform. Imputed income prevents a parent from strategically reducing income to lower their child support obligation.

Arizona's guidelines include a parenting time credit that reduces a parent's financial obligation when they exercise substantial parenting time beyond a minimum threshold. The parenting time credit recognizes that when a parent has the child for more nights, they are directly bearing more of the everyday costs of raising that child — food, clothing, utilities, activities — and it would be inequitable to also require them to pay the full guideline transfer amount that was calculated assuming minimal overnight contact.

The credit is calculated using a formula that compares the parent's actual parenting time — measured in overnights per year — to a baseline. As the number of overnights increases, the credit increases proportionally. Arizona uses a specific table or formula in the guidelines that converts overnight percentages into credit percentages applied to the basic obligation. The credit can significantly reduce the transfer payment for a parent who has the child for 40% or more of overnights.

It is important to note that the parenting time credit in Arizona is based on time the parent actually exercises, not merely time that is awarded in the parenting plan. Courts may require documentation of actual parenting time if the parties dispute the credit. Additionally, the credit cannot reduce the obligation below zero — if the credit would otherwise result in the lower-income parent paying the higher-income parent, the court must evaluate the equities of such a result before entering an order.

Arizona adds healthcare and childcare costs to the basic obligation determined from the guideline schedule before apportioning the total between the parents. Health insurance premiums attributable to the child are identified — typically by comparing the cost of employee-only coverage to the cost of employee-plus-child or family coverage — and added to the basic obligation. The combined total is then divided proportionally based on each parent's share of combined adjusted gross income.

Work-related childcare expenses are treated similarly. The net cost of childcare — after subtracting any child and dependent care tax credit the paying parent receives — is added to the support calculation. Arizona limits the includable childcare to costs that are necessary for the parent to maintain employment or attend school or job training. Voluntary childcare expenses unrelated to employment are not included in the guideline calculation.

Extraordinary medical costs, such as significant unreimbursed dental work, vision care, mental health treatment, or physical therapy, may be shared proportionally by the parents in addition to the regular support amount. Arizona courts often include provisions in the support order directing the parents to share these costs in the same proportion as their income. This avoids repeated court appearances over individual medical expenses and gives both parents a clear framework for handling unanticipated costs.

Arizona's child support guidelines include a self-sufficiency reserve provision designed to protect obligors at very low income levels. The reserve ensures that the guideline calculation does not consume so much of a low-income parent's earnings that they are left unable to meet their own basic subsistence needs. If applying the full guideline amount would leave the obligor with less than the self-sufficiency reserve amount, the court may set support at a reduced level.

The self-sufficiency reserve is not a blanket minimum income floor but rather a backstop that prevents severe hardship. Courts apply it case by case, considering the actual living expenses of the obligor and whether the proposed support amount would leave the parent unable to maintain stable housing and employment. The reserve does not eliminate the obligation — it simply caps it at a level the obligor can realistically pay, which also serves the child's long-term interest since an achievable support amount is more likely to actually be paid.

Arizona courts and the Child Support Advisory Committee periodically review the self-sufficiency reserve amount to ensure it reflects actual subsistence costs in the state. Parents seeking to have the reserve applied should provide detailed documentation of their income, necessary living expenses, and any other child support or spousal maintenance obligations they are currently paying. The burden of demonstrating that the reserve should apply rests on the party seeking the reduction from the standard guideline amount.