Arizona Child Support Modification Guide
Understand the substantial and continuing change standard, parenting time adjustments, guideline recalculation, and the full Superior Court process for modifying child support under A.R.S. § 25-503.
Last Reviewed: January 20, 2025
Next Review: January 2026
Quick Reference: Arizona Modification Facts
15% change and at least $50/month difference (Arizona Guidelines § 21)
Triggered at 128 overnights (35% of the year)
Either parent may request review every 3 years without showing a change
Generally from filing/service date; retroactive relief is rare
Legal Standards & Practical Considerations
Quantitative Threshold
Recalculations showing a 15% (and $50/month) difference are presumed substantial. Use the current worksheet to verify the variance before filing.
Reference: Arizona Child Support Guidelines § 21
Parenting Time Adjustment
A credit applies when the non-primary parent has at least 128 overnights. Track actual parenting time carefully; calendars and signed parenting plans are persuasive evidence.
Reference: Arizona Guidelines § 18 & § 11
Effective Date & Retroactivity
Modifications take effect from filing or service. Courts rarely grant retroactive adjustments unless the delay was beyond your control. File as soon as the change occurs.
Qualifying Conditions for Modification
These are the most common reasons Arizona courts approve a child support modification petition.
| Condition | Threshold | Timeframe | Examples | Legal Basis |
|---|---|---|---|---|
| Income Change | ≥ 15% change producing ≥ $50/month variance | Ongoing change since the last order | Layoff, salary reduction, new employment, loss of overtime/bonuses | A.R.S. § 25-503(E); Arizona Guidelines § 24 |
| Parenting Time Shift | Change crossing 128-night (35%) parenting credit threshold | Sustained schedule change | Move to 60/40 schedule, long-distance relocation, equal parenting plan | Arizona Guidelines § 18 |
| Health Insurance Costs | Material change in premium or coverage availability | Since last order | Loss of employer plan, premium increase, new marketplace coverage | Arizona Guidelines § 9 |
| Childcare & Education | Significant change in necessary expenses | Since last order | Child begins/ends daycare, special education or tutoring costs | Arizona Guidelines § 10 |
| Medical / Special Needs | New or increased unreimbursed medical costs | Ongoing condition | Chronic illness diagnosis, therapy, recurring medical equipment | Arizona Guidelines § 9(B) |
| Three-Year Review | Automatic review right every 36 months | 36 months since entry/modification | Routine DES review, income drift without major events | A.R.S. § 25-327(A); DES CSS Policy |
Step-by-Step Modification Process
Follow these eight steps to file and complete an Arizona child support modification through the Superior Court.
Evaluate whether current circumstances would change support by at least 15% and $50/month using the Arizona Child Support Worksheet. Confirm the change is ongoing and not temporary.
Required Documents
Latest support order, income records, Child Support Worksheet, parenting calendars
Expected Timeline
Before filing
Collect income proof for both parents (pay stubs, tax returns, profit & loss statements), health insurance invoices, childcare receipts, and updated parenting time logs.
Required Documents
Last 3 months pay stubs, two years tax returns, proof of benefits, parenting schedules
Expected Timeline
1-2 weeks
Fill out the Petition to Modify Child Support (Arizona Superior Court Form DRMC7) and the current Child Support Worksheet using the latest guidelines.
Required Documents
DRMC7 petition, Child Support Worksheet, Affidavit of Financial Information (AFI)
Expected Timeline
1 week
File the petition, worksheet, and financial affidavit with the Superior Court clerk that issued the existing order. Pay the filing fee or request a fee waiver.
Required Documents
Petition packet, filing fee (~$89) or fee-deferral application
Expected Timeline
Same day
Serve the filed documents using certified mail with return receipt, sheriff, or private process server, then file proof of service with the court.
Required Documents
Copies of filed pleadings, Summons, Proof/Acceptance of Service
Expected Timeline
Within 120 days of filing
Both parties must exchange Affidavits of Financial Information and supporting proof within 40 days. Provide updates if new pay stubs or expenses arise.
Required Documents
Affidavit of Financial Information, income proof, expense receipts
Expected Timeline
Within 40 days after service
Many counties schedule a Resolution Management Conference or hearing. Prepare exhibits, updated worksheets, parenting logs, and witness lists. Consider settlement or mediation.
Required Documents
Updated worksheet, exhibits, proposed findings, settlement proposals
Expected Timeline
2-4 weeks before hearing
Present evidence and testimony. After the court issues the modified order, submit it to DES Child Support Services for enforcement and adjust payments immediately.
Required Documents
Hearing exhibits, proposed order, wage assignment, DES notification forms
Expected Timeline
Hearing within 3-6 months of filing; modify payments immediately after order
Real-World Modification Scenarios
These examples illustrate how Arizona courts apply the substantial and continuing change requirement in everyday situations.
Situation: Robert paid $1,100/month based on a $75,000 salary. After a layoff, his new job pays $52,500 (30% decrease).
Action: Filed petition with termination notice, new offer letter, recent pay stubs, and updated worksheet showing a 28% decrease.
Outcome: Court reduced support to approximately $790/month, reflecting the involuntary and substantial income change.
Situation: Maria moved from alternate weekends (~52 nights) to 146 nights per year (40%) while earning $55k; the other parent earns $85k.
Action: Submitted new parenting plan and overnight logs; worksheet showed eligibility for the parenting time adjustment.
Outcome: Support adjusted from $1,250 to about $900/month because of increased direct expenses during Maria’s parenting time.
Situation: Daniel receives $650/month. Three years later his ex-spouse’s income increased from $45k to $62k (38% rise).
Action: Requested review without proving additional change, providing updated income documents and worksheet.
Outcome: Support increased to roughly $900/month to reflect the higher income share.
Situation: Lisa’s insurance premium for the children rose from $150 to $400/month, while kindergarten eliminated $600 childcare cost.
Action: Filed with premium invoices and proof of reduced childcare; worksheet showed net $350 decrease in add-ons.
Outcome: Court reduced combined obligation by ~$350/month, split proportionally between the parents.
Frequently Asked Questions
Arizona courts view a change as substantial when it would alter the guideline amount by at least 15% and $50/month (Arizona Guidelines § 21). Examples include involuntary income loss, significant raises, changes in parenting time, new health insurance costs, or elimination of childcare expenses.
You may seek modification at any time if you can show a substantial and continuing change. Additionally, either parent can request a review every three years without proving a change (A.R.S. § 25-327(A)).
Generally, modifications take effect from the date you file the petition or serve the other parent. Retroactive relief is rare, so file immediately once the change occurs.
Arizona uses gross income including wages, bonuses, self-employment income, rental income, unemployment, disability benefits, and pensions. Courts may “add back” personal expenses paid through a business when calculating net income.
Representing yourself is allowed and DES Child Support Services provides forms, but modification cases involving complex income, parenting disputes, or self-employment often benefit from legal counsel.
When the non-primary parent has 128 or more overnights (35%+), the parenting time adjustment reduces the paying parent’s obligation to reflect direct expenses during their parenting time (Arizona Guidelines § 18).