Oregon Child Support Guidelines: How Support Is Calculated
September 10, 2026 · LawDiver Research Team
Oregon uses a Income shares framework under Or. Rev. Stat. §§ 25.275–25.280; Oregon Child Support Guidelines (OAR). This guide explains how courts calculate support from gross income, when judges may deviate, how modification works, and how leading Oregon opinions apply the statute. Pair this article with the CaseDiver search rail to pull additional Oregon family-law decisions.
Primary keywords: Oregon child support guidelines, Oregon child support calculator, ORS 25.275, modify Oregon child support
Key takeaways
- Oregon follows the Income shares model for presumptive child support.
- Income is generally measured using gross income, then allocated under Or. Rev. Stat. §§ 25.275–25.280; Oregon Child Support Guidelines (OAR).
- Guideline amounts are presumptive, not automatic — courts may deviate when the facts justify it.
- Support generally continues until 18, or 21 if the child is attending school as defined by statute.
- Either parent can seek modification when substantial change in circumstances; a 15% difference or change in parenting time commonly supports review..
- Read the companion guide: Oregon alimony / spousal support.
Statutory framework and guideline model
Oregon's child support system is built around Or. Rev. Stat. §§ 25.275–25.280; Oregon Child Support Guidelines (OAR). Under the income shares, Oregon’s scale uses combined incomes and a percentage obligation that varies with income level, then divides by income share. Parenting-time credits, medical support, and childcare enter the online guideline calculator used statewide.
Federal law requires every state to maintain presumptive guidelines and to review them at least every four years (42 U.S.C. § 667). Confirm the latest Oregon schedule or worksheet before relying on any online calculator.
How child support is calculated in Oregon
- Identify each parent's guideline income using gross income as defined in Or. Rev. Stat. §§ 25.275–25.280; Oregon Child Support Guidelines (OAR) and the accompanying worksheets or administrative rules.
- Apply the income shares — whether that means a combined-income schedule, an obligor percentage table, or a Melson-style self-support reserve plus primary obligation.
- Allocate add-ons such as health insurance premiums, unreimbursed medical expenses, and work-related child care according to Oregon practice.
- Consider parenting time adjustments where the guidelines or case law authorize a credit or shared-custody formula.
- Test for deviation if a strict guideline result would be unjust or inappropriate on the record.
Online calculators can illustrate ranges, but only the controlling statute, guidelines, and court findings produce an enforceable order.
Deviation from the guidelines
Rebuttal criteria in the guidelines include extraordinary expenses and other inequitable circumstances.
When a court departs from the presumptive amount, Oregon practice generally requires findings that explain why the guideline figure is unjust or inappropriate and what amount better serves the child's needs. Those findings matter on appeal and in later modification proceedings.
Modification of child support
Substantial change in circumstances; a 15% difference or change in parenting time commonly supports review.
A parent seeking a change typically must show that circumstances after the prior order make the existing award inequitable. Common triggers include job loss, substantial income changes, a new parenting-time schedule, emancipation of a child, or extraordinary medical needs. Retroactivity and temporary relief rules are statute-specific — check Or. Rev. Stat. §§ 25.275–25.280; Oregon Child Support Guidelines (OAR) and local family-division procedures.
Enforcement in Oregon
Division of Child Support enforces with withholding, intercepts, and contempt.
Interstate cases often implicate UIFSA. Income withholding, contempt, license suspension, and tax-refund intercept remain core tools nationwide, but the Oregon child support agency and clerk of court procedures control day-to-day collection.
When child support ends
In Oregon, Support generally continues until 18, or 21 if the child is attending school as defined by statute. Orders may extend for disability, secondary education, or other statutory grounds where the statute allows. Always read the judgment language — agreed orders sometimes set a different end date or require a notice of emancipation.
Case law: how Oregon courts apply the guidelines
The opinions below are in the LawDiver corpus. Each block quote is taken from the opinion text so you can jump from this guide into the full decision.
In the Matter of the Dissolution of the Marriage of McCLURE, and McCLURE
In the Matter of the Dissolution of the Marriage of McCLURE, and McCLURE, 16 Or. App. 680 (1974)
…of the children to the wife and required the husband to pay child support of $125 per month per child and support to the wife of $100 per month until the death or remarriage of the wife. The decree in effect gave the wife more than she sought by her testimony which was: “Q [Do you feel that you should have] * $100 for the support and maintenance for yourself until such time…
Courts and practitioners still cite this opinion when litigating oregon child support issues. Open the full text on LawDiver to read the holding in context.
In the Matter of the Dissolution of the Marriage of GROVE, Respondent, and GROVE, Petitioner
…ions in the dissolution decree for division of property and child support. Legislative recognition of this interrelationship is found in paragraphs (E), (F) and (G) of ORS 107.105(l)(c). In practice, the financial portions of a dissolution decree are worked out together, and none can be considered in isolation. For example, one spouse may be awarded specific assets as part of t…
Courts and practitioners still cite this opinion when litigating oregon child support issues. Open the full text on LawDiver to read the holding in context.
In the Matter of the Dissolution of the Marriage of FULWILER, Respondent, and FULWILER, Appellant
…ivided equitably. Husband was ordered to pay $150 per month child support, and $250 per month for wife’s support for three years (through January 1, 1978) and thereafter $150 per month, subject to termination by remarriage after' three years, or demise. *313 Wife worked during the early years of the marriage, and undoubtedly is capable of working now, although she has back trou…
Courts and practitioners still cite this opinion when litigating oregon child support issues. Open the full text on LawDiver to read the holding in context.
DA Family Support v. Kyei
DA Family Support v. Kyei, 315 Or. App. 69 (2021)
…tered in Clackamas County in June 2017, and the Division of Child Support of the Department of Justice garnished his wages pursuant to that order. Appellant challenged the support order and the garnishment in the Clackamas County Circuit Court, contending that his obli- gation to pay child support had been terminated pursuant to a 2013 stipulated judgment entered in Multnomah C…
Courts and practitioners still cite this opinion when litigating oregon child support issues. Open the full text on LawDiver to read the holding in context.
Practical checklist for Oregon child support matters
- Gather recent pay stubs, tax returns, and proof of health insurance / child-care costs.
- Complete the current Oregon worksheet or financial affidavit required by the local court.
- Document parenting-time overnights if a shared-custody adjustment may apply.
- Flag facts that could support deviation (special needs, travel costs, high income, other children).
- Search LawDiver for recent Oregon appellate decisions before mediation or trial.
Frequently asked questions
How is child support calculated in Oregon?
Oregon uses the income shares under Or. Rev. Stat. §§ 25.275–25.280; Oregon Child Support Guidelines (OAR). Courts start with gross income, apply the guideline schedule or percentage, allocate add-ons, and may deviate with findings when the presumptive amount is unjust.
What income counts for Oregon child support?
Guideline income generally tracks gross income as defined by Or. Rev. Stat. §§ 25.275–25.280; Oregon Child Support Guidelines (OAR) and the worksheets. Wages, self-employment income, bonuses, and certain benefits are commonly included; exact deductions and exclusions are statute-specific.
Can Oregon courts order more or less than the guideline amount?
Yes. Guideline support is presumptive. Judges may deviate when the record shows the guideline result is unjust or inappropriate, typically with written findings explaining the departure.
How do I modify a Oregon child support order?
Substantial change in circumstances; a 15% difference or change in parenting time commonly supports review. File in the court with continuing jurisdiction (or follow UIFSA for interstate cases) and support the request with current financial evidence.
When does child support end in Oregon?
Support generally continues until 18, or 21 if the child is attending school as defined by statute. Confirm any disability, educational, or agreed extensions in your particular order.
Where can I research Oregon child support case law?
Use LawDiver CaseDiver search scoped to Oregon, or open the opinions linked in this guide. Companion reading: Oregon spousal support guide.
Disclaimer
This guide is general legal information about Oregon child support, not legal advice. Statutes, guidelines, and case law change. Confirm the current text of Or. Rev. Stat. §§ 25.275–25.280; Oregon Child Support Guidelines (OAR) and consult a licensed Oregon family-law attorney about your facts.