How to Modify Child Support in Arizona
Reviewed by DocDraft Legal Team · Arizona · Last updated September 21, 2026
In Arizona, a child support modification is a court, or the state child support agency, changing the amount of an existing child support order after a substantial and continuing change of circumstances (A.R.S. 25-327). Arizona's distinctive rule is a shortcut: when a fresh guideline calculation would differ by 15 percent or more from your current order, that variation is treated as evidence of a substantial and continuing change of circumstances, which opens a simplified modification (Arizona Child Support Guidelines). Support in Arizona follows a statewide guideline tied to each parent's income and parenting time (A.R.S. 25-320), so a job loss, an income change, or a new parenting schedule can push the current amount too high or too low. You have two paths. You can file a Petition to Modify (Change) Child Support, Simplified Process (Form DRMSS11F), in the superior court that issued your order, or you can ask the Division of Child Support Services to review your case. A change takes effect on the first day of the month following notice of the petition, not back to when your circumstances changed, so support that already came due cannot be wiped out (A.R.S. 25-327). You can also ask for a review about every three years. Keep paying your current order until it is changed. Attorney review of your filing is available through DocDraft.
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How do I modify child support in Arizona?
File a Petition to Modify (Change) Child Support, Simplified Process (Form DRMSS11F), in the superior court that issued your order, or ask the Division of Child Support Services to review your case. You must show a substantial and continuing change of circumstances; a recalculation differing 15 percent or more from your order qualifies (A.R.S. 25-327).
How much does the amount have to change to modify child support in Arizona?
Arizona treats a variation of 15 percent or more between your current order and a fresh guideline calculation as evidence of a substantial and continuing change of circumstances, which opens the simplified modification process. Smaller changes can still qualify if you prove the change is substantial and continuing (A.R.S. 25-327).
How far back can a child support change go in Arizona?
A modification takes effect on the first day of the month following notice of the petition, not back to when your circumstances changed (A.R.S. 25-327). A court can set a different date for good cause but not earlier than the filing date, so file promptly and keep paying meanwhile.
Who handles child support modifications in Arizona?
The superior court in the county where your order was issued handles modifications. If the Division of Child Support Services manages your case, either parent can ask it to review the order; the agency recalculates under the guideline and files a petition with the superior court when a change is warranted.
Arizona child support modification at a glance
In Arizona, a child support modification is a court, or the Division of Child Support Services, changing the amount of an existing order after a substantial and continuing change of circumstances (A.R.S. 25-327). Arizona's shortcut is the 15 percent rule: when a new guideline calculation would differ by 15 percent or more from your current order, that variation is treated as evidence of a substantial and continuing change and opens a simplified modification (Arizona Child Support Guidelines). Support follows a statewide guideline tied to income and parenting time (A.R.S. 25-320). You file a Petition to Modify (Change) Child Support, Simplified Process (Form DRMSS11F), in the superior court that issued your order, or ask the agency to review. A change applies from the first day of the month following notice of the petition, so support already due cannot be erased (A.R.S. 25-327).
Lowering an Arizona order after a pay cut
Suppose an Arizona order was set two years ago and your hours were just cut, and a fresh guideline calculation now comes out 20 percent lower, which clears Arizona's 15 percent simplified threshold (Arizona Child Support Guidelines). You complete the Petition to Modify (Change) Child Support, Simplified Process (Form DRMSS11F), attach a Parent's Worksheet showing your lower income, and file it in the superior court that issued your order. Because the change takes effect only on the first day of the month following notice of your petition (A.R.S. 25-327), you file right away and keep paying the current amount until the court rules. The court recalculates under the guideline (A.R.S. 25-320) and enters a lower order. Attorney review of your filing is available through DocDraft.
Relevant Laws
A.R.S. 25-327 (modification and effective date of support)
Provides that a support order may be modified or terminated only on a showing of changed circumstances that are substantial and continuing, and that modifications are effective on the first day of the month following notice of the petition, not earlier than the date of filing.
A.R.S. 25-320 (child support and statewide guideline)
Requires child support to be set using the amount produced by the Arizona Child Support Guidelines unless a written finding shows that applying the guidelines would be inappropriate or unjust in a particular case.
Arizona Child Support Guidelines (15 percent simplified procedure)
Adopted by the Arizona Supreme Court, the guidelines provide that a variation of 15 percent or more between the existing order and a new guideline calculation is considered evidence of a substantial and continuing change of circumstances for a simplified modification.
Arizona Judicial Branch self-service: modifying child support
The Arizona Judicial Branch self-service center provides the statewide Petition to Modify (Change) Child Support, Simplified Process (Form DRMSS11F) and related worksheets, and explains how to file to change a child support order.
Regional Variances
Arizona child support modification rules at a glance
Qualifying threshold
You must show a substantial and continuing change of circumstances (A.R.S. 25-327). A variation of 15 percent or more between your current order and a fresh guideline calculation is treated as evidence of that change and opens a simplified modification (Arizona Child Support Guidelines).
Where to file
The superior court in the county that issued your order. If the Division of Child Support Services manages your case, either parent can ask the agency to review and, when warranted, it files a petition with the superior court.
Modification form
The statewide Petition to Modify (Change) Child Support, Simplified Process (Form DRMSS11F), filed with a Parent's Worksheet for Child Support Amount. Some county superior courts use their own versions, so confirm with the issuing court.
Retroactivity
A change is effective on the first day of the month following notice of the petition, not earlier than the filing date, and only for good cause can the court set a different date (A.R.S. 25-327). Support already due cannot be reduced.
Periodic review
If the Division of Child Support Services handles your case, you can generally request a review about every three years even without a change, and sooner when a substantial and continuing change occurs (45 CFR 303.8).
Suggested Compliance Checklist
Recalculate support and check the 15 percent variation
Before you file days after startingRun a fresh guideline calculation using current income and parenting time (A.R.S. 25-320) and compare it to your current order; a 15 percent or greater variation opens the simplified process. Attorney review of your filing is available through DocDraft.
Gather proof of your changed circumstances
Before you file days after startingCollect current pay stubs, tax returns, and proof of the change, such as a job loss, an income change, or a new parenting schedule, so you can complete a sworn Parent's Worksheet for Child Support Amount.
Complete the simplified petition (Form DRMSS11F)
As soon as your circumstances change days after startingFill out the Petition to Modify (Change) Child Support, Simplified Process (Form DRMSS11F), from the Arizona Judicial Branch self-service center, describe the change, and attach your worksheet. Some counties use their own forms.
File with the superior court
Promptly (the change dates from notice of the petition) days after startingFile your petition with the clerk of the superior court that issued your order and pay the fee or request a waiver. Because the change is effective from notice of the petition, file promptly (A.R.S. 25-327).
Give notice to the other parent
After filing, per court rules days after startingServe or notify the other parent as the court requires and file proof. Notice of the petition sets the earliest effective date for any change, so complete it correctly and on time (A.R.S. 25-327).
Consider a Division of Child Support Services review
Anytime the agency handles your case days after startingIf the Division of Child Support Services manages your case, ask it to review your order. The agency recalculates under the guideline and, when a 15 percent or greater change is warranted, files a petition with the superior court.
| Task | Description | Document | Days after starting |
|---|---|---|---|
| Recalculate support and check the 15 percent variation | Run a fresh guideline calculation using current income and parenting time (A.R.S. 25-320) and compare it to your current order; a 15 percent or greater variation opens the simplified process. Attorney review of your filing is available through DocDraft. | - | Before you file |
| Gather proof of your changed circumstances | Collect current pay stubs, tax returns, and proof of the change, such as a job loss, an income change, or a new parenting schedule, so you can complete a sworn Parent's Worksheet for Child Support Amount. | - | Before you file |
| Complete the simplified petition (Form DRMSS11F) | Fill out the Petition to Modify (Change) Child Support, Simplified Process (Form DRMSS11F), from the Arizona Judicial Branch self-service center, describe the change, and attach your worksheet. Some counties use their own forms. | - | As soon as your circumstances change |
| File with the superior court | File your petition with the clerk of the superior court that issued your order and pay the fee or request a waiver. Because the change is effective from notice of the petition, file promptly (A.R.S. 25-327). | - | Promptly (the change dates from notice of the petition) |
| Give notice to the other parent | Serve or notify the other parent as the court requires and file proof. Notice of the petition sets the earliest effective date for any change, so complete it correctly and on time (A.R.S. 25-327). | - | After filing, per court rules |
| Consider a Division of Child Support Services review | If the Division of Child Support Services manages your case, ask it to review your order. The agency recalculates under the guideline and, when a 15 percent or greater change is warranted, files a petition with the superior court. | - | Anytime the agency handles your case |
Frequently Asked Questions
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