An Arizona petition to modify child support is the court filing you use to change an existing support order when your circumstances have shifted enough to justify a different amount. File it with the Clerk of the Superior Court in the county that issued your current order. If both parents agree and the recalculated amount differs from the existing order by at least 15%, Arizona offers a simplified process that avoids a hearing. If you can’t agree, the same petition goes through the standard court process in front of a judge.
Do Your Circumstances Qualify?
Arizona requires a “changed circumstance that is substantial and continuing” before a court will modify support.1Arizona Legislature. Arizona Code 25-503 – Order for Support; Methods of Payment; Modification A slow quarter at work probably won’t qualify. A permanent job change, a layoff that drops your income significantly, or a shift from full-time to part-time work likely will. A lasting pay increase for either parent, a change in what health insurance for the children costs, or a real change in how much parenting time each parent exercises can all qualify as well.
Health insurance gets a specific nod in the statute. Adding coverage for a child or losing employer-sponsored coverage can, on its own, count as a substantial and continuing change.1Arizona Legislature. Arizona Code 25-503 – Order for Support; Methods of Payment; Modification
The 15% Rule and the Simplified Process
Arizona’s simplified modification process lets you skip the hearing entirely. Two conditions apply: the recalculated child support amount must differ from the current order by at least 15%, and both parents must agree to the change.2Arizona Department of Economic Security. Modification Review and Referral SW The 15% gap is treated as built-in proof that the change is substantial, so you don’t have to argue the point separately.
If your numbers come in under 15%, or the other parent won’t sign, you can still file. You just move to the standard court process, where you prove the substantial-and-continuing-change standard directly at a hearing.
The Three-Year Review Through DCSS
Parents whose support is enforced through Arizona’s Division of Child Support Services (a Title IV-D case) have another option. Every three years, either parent can ask DCSS to review the order and adjust it, without having to prove a substantial change at all. DCSS runs the current guidelines and, if the result warrants a change, files the petition with the court for you. Asking for a review inside that three-year window puts you back on the substantial-and-continuing-change standard.1Arizona Legislature. Arizona Code 25-503 – Order for Support; Methods of Payment; Modification
What Income Goes Into the Calculation
The worksheet starts with each parent’s gross monthly income before taxes. Arizona reads “income” broadly: wages, salaries, commissions, bonuses, self-employment earnings, rental income, pensions, Social Security benefits (including SSDI), unemployment and workers’ compensation, military pay and disability benefits, trust income, capital gains, dividends, interest, spousal maintenance received, and recurring gifts.3Superior Court of Maricopa County. Child Support Worksheet Instructions
A short list is excluded: TANF, Supplemental Security Income (SSI), food stamps, and child support received from another case.3Superior Court of Maricopa County. Child Support Worksheet Instructions SSDI and SSI get confused constantly: SSDI is income and can be garnished for support; SSI is neither.
If a parent is unemployed or underemployed, the court can impute income. Arizona presumes a noncustodial parent is capable of earning at least the higher of the state or federal minimum wage, working full time.4Arizona Legislature. Arizona Code 25-320 – Child Support; Factors; Methods of Payment Quitting a job to lower support doesn’t produce the result some parents expect.
Documents to Gather Before You Start
Pull the following for both parents before you touch the forms:
- Gross monthly income: recent pay stubs, tax returns if self-employed, documentation of benefits
- Monthly premium for the children’s health insurance coverage
- Monthly childcare costs that let a parent work
- Parenting time: the number of days each parent has with the child annually under the current order
The Forms You’ll File
The core packet for the simplified process is on the Arizona Judicial Branch site:5Arizona Judicial Branch. Modifying Child Support
- Petition to Modify Child Support (Simplified Process), the main request
- Child Support Worksheet, where the calculation happens
- Child Support Order, the proposed new order for the judge to sign
Fill the worksheet first. Each parent’s gross income goes in, certain adjustments come off, insurance and childcare costs factor in, and the parenting-time allocation applies. The instructions walk through each line. The final figure becomes the proposed amount in the petition. If it differs from your current order by at least 15% and the other parent agrees, you’re in the simplified lane.
Where to File and What It Costs
File with the Clerk of the Superior Court in the county that issued your most recent child support order.6Arizona Legislature. Arizona Code 25-502 – Jurisdiction, Venue and Procedure; Additional Enforcement Provisions You can request a transfer to the county where the child lives, but the case begins where the last order was entered.
The clerk charges a filing fee. In Maricopa County it’s $102 for a child support modification.7Clerk of the Superior Court of Maricopa County. Filing Fees Fees vary by county, so check with your local clerk. If you can’t pay, Arizona allows a deferral or waiver. Parents receiving SSI with documentation generally qualify for a full waiver. Those on TANF or food stamps, or with income between 150% and 225% of the federal poverty level, may qualify for a deferral or payment plan.8Arizona Judicial Branch. Fee Waivers and Deferrals
Serving the Other Parent
When both parents sign the simplified petition, formal service generally isn’t needed. The signature works as acknowledgment and acceptance.
If the other parent hasn’t signed, you must serve them. Under Arizona’s Rules of Family Law Procedure, service can be made by:
- Personal delivery: handing the documents directly to the other parent
- Substituted service: leaving copies at the other parent’s home with someone of suitable age and discretion who lives there
- Mail or national courier with restricted delivery, requiring the addressee’s signed receipt
You can’t serve the other parent yourself. The person who delivers the papers must be at least 18 and not a party to the case. File the proof of service with the court once it’s done.
If the Other Parent Won’t Agree
The simplified process only works when both sides sign. If the other parent refuses, objects to the proposed amount, or ignores the paperwork, you move to a standard modification: file the petition, serve the other parent, and appear at a hearing where a judge decides whether a substantial and continuing change exists.
The other parent can file a response arguing no qualifying change occurred or that your calculation is off. The judge weighs both sides and applies the guidelines independently. Clean documentation of income and expenses matters most here, because the judge works only with what’s in front of them.
What Happens After You File
Under the simplified process, a judicial officer reviews the signed packet without a hearing. The review checks that the forms are complete, the worksheet follows the guidelines, and the proposed order matches the numbers.5Arizona Judicial Branch. Modifying Child Support If everything is in order, the judge signs the proposed order, it replaces the old one, and the clerk mails copies to both parents.
If something is off, the petition can come back for corrections or get set for a hearing. Worksheet math errors are the usual culprit, so recheck the calculation before you file.
When the New Amount Starts
Under A.R.S. § 25-503, the modified amount takes effect the first day of the month after the other parent receives notice of the petition.1Arizona Legislature. Arizona Code 25-503 – Order for Support; Methods of Payment; Modification In the simplified process, notice effectively occurs when both parents sign. The court can set a different effective date for good cause but cannot reach back earlier than the filing date. The modification does not erase arrears that accumulated before notice. Those unpaid amounts stay enforceable regardless of the new order, which is why filing promptly after circumstances change matters.
If One Parent Lives Out of State
Arizona may not be the right court. Under A.R.S. § 25-1225 and the Uniform Interstate Family Support Act, an Arizona court keeps exclusive jurisdiction to modify its own order only while the obligor, the obligee, or the child still lives in Arizona when modification is requested.9Arizona Legislature. Arizona Code 25-1225 – Continuing, Exclusive Jurisdiction to Modify Child Support Order
If everyone has left the state, Arizona loses exclusive jurisdiction. Both parties can agree in writing to let another state take over, or the parent seeking the change can file where the child now lives. An Arizona court without jurisdiction can still forward the request to the state that does have it, acting as an initiating tribunal.9Arizona Legislature. Arizona Code 25-1225 – Continuing, Exclusive Jurisdiction to Modify Child Support Order Settle the jurisdiction question before you file, so your petition doesn’t get dismissed months in.