Arkansas Administrative Order 10: How Child Support Is Calculated

Arkansas calculates child support using Administrative Order No. 10 (AO10), an Income Shares model that replaced the old percentage-of-obligor-income formula in July 2020. The core principle: a child of separated parents should receive the same proportion of parental income they would have received if the family had stayed together. Both parents' earnings matter, and the amount each parent pays depends on their share of the combined income — not just the non-custodial parent's paycheck.

The Income Shares Calculation

The AO10 calculation follows a specific sequence:

1. Determine each parent's gross monthly income. This includes wages, salaries, commissions, bonuses, self-employment earnings, pensions, and disability benefits. Both parents must complete an Affidavit of Financial Means and provide two years of federal tax returns. These financial disclosures must be exchanged at least three days before any court hearing.

2. Combine both incomes. Add both parents' gross monthly incomes together.

3. Look up the Basic Child Support Obligation (BCSO). The AO10 Monthly Family Support Chart lists the presumptive support amount based on the combined income and the number of children.

4. Calculate each parent's proportional share. If Parent A earns $5,000/month and Parent B earns $3,000/month, their combined income is $8,000. Parent A's share is 62.5% and Parent B's share is 37.5%.

5. Add mandatory expenses. Three child-related costs are added to the base obligation and split proportionally: the child's health insurance premiums, work-related childcare costs, and extraordinary out-of-pocket medical expenses exceeding $250 per child per year.

6. Determine the final order. The non-custodial parent's support obligation is their proportional share of the BCSO plus their share of add-on expenses, minus any credits for expenses they pay directly (such as carrying the child's health insurance).

The 141-Overnight Threshold

This is the number that changes everything in shared custody arrangements. Under standard calculations, the model assumes the non-custodial parent has fewer than 141 overnights per year. In that scenario, the full proportional share applies — no adjustment.

When the non-custodial parent exercises 141 or more overnights annually, the arrangement qualifies as shared physical custody under AO10. The court then has discretion to apply the offset method:

1. Calculate each parent's child support obligation as if they were the non-custodial parent
2. Subtract the lower obligation from the higher
3. The higher-earning parent pays the net difference to the lower-earning parent

Using the example above: if Parent A's obligation (calculated as if non-custodial) is $898 and Parent B's is $538, Parent A pays the difference — $360 per month. Compare that to the standard calculation where Parent A would pay the full $898.

The 141-overnight threshold is not self-executing. The adjustment is discretionary — the court evaluates income disparity, which parent bears non-duplicated fixed expenses (school clothing, registration fees, equipment), and direct household costs during parenting time. In practice, most judges apply the offset when the overnight count clearly exceeds 141.

Tracking Overnights Accurately

The difference between 139 and 142 overnights can be hundreds of dollars per month in child support. This makes overnight tracking critical. Count every night the child sleeps at your residence, including:

• Regular weeknight visits with overnights
• Weekend visitation blocks
• Holiday overnights
• Summer break blocks
• School holidays and teacher workdays

A common mistake: parents assume their schedule generates a specific overnight count without actually doing the math. A 2-2-3 rotation produces about 182 overnights per parent. Alternating weekends with a midweek overnight lands around 135-150, depending on whether the midweek visit includes an overnight. Standard visitation without midweek overnights typically falls under 100.

The Self-Support Reserve

AO10 protects low-income obligors. If a parent's monthly gross income falls below the Self-Support Reserve threshold of $900, the court applies a presumptive minimum support order of $125 per month rather than the calculated amount. This prevents a support order from pushing the paying parent below subsistence level.

At the upper end, the AO10 family support chart caps combined parental gross monthly income at $30,000. For families above that threshold, the judge has discretion to adjust the obligation upward based on the child's needs and the parents' standard of living.

Common Mistakes Parents Make

Hiding income. Courts can impute income to a parent who is voluntarily underemployed or unemployed. If you quit a $60,000 job and take a part-time position to lower your support obligation, the judge can calculate support based on your earning capacity rather than your actual income.

Ignoring add-on expenses. Health insurance premiums and childcare costs are not optional additions — they are mandatory components of the calculation. Forgetting to include them in your initial proposal creates problems when the judge reviews the worksheet.

Assuming 50/50 custody eliminates support. Even in a perfectly equal arrangement, the higher-earning parent will almost always owe some child support. The offset method reduces the amount but rarely eliminates it unless both parents earn nearly identical incomes.

Running Your Own Calculation

The Arkansas Judiciary provides an official Child Support Calculator on the court system website. It walks you through the AO10 worksheet step by step, including the shared-custody offset. You will need both parents' gross monthly incomes, health insurance premiums, and childcare costs.

The Arkansas Child Custody and Parenting Plan Guide includes a detailed AO10 walkthrough with worked examples showing how different overnight counts and income combinations affect the final support amount, so you can see exactly where your situation falls before mediation or your court date.

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