Child support in Oregon.
What the state’s own guideline says, where the number comes from, and the one figure that moves it more than anything you will argue about.
See a different stateOregon
Oregon combines both parents' incomes, uses an Obligation Scale to find the basic support amount for that combined income and number of children, and divides it by income share. Oregon then applies a parenting time credit that moves continuously with the number of overnights, rather than switching on at a threshold, and subtracts a self-support reserve so a paying parent keeps enough to live on.
How Oregon works out the number
Authority: ORS 25.270 through 25.290 require support to be calculated by formula; the formula is the Oregon Child Support Guidelines at OAR 137-050-0700 through 137-050-0765 plus the Obligation Scale in the appendix. The compiled rules with official commentary carry an effective date of July 1, 2026 for the self-support reserve rule, OAR 137-050-0745.Yes, and it is a smooth curve with no threshold. Each parent's credit percentage is computed as credit = 1/(1+e^(-7.14*((overnights/365)-0.5))) – 2.74% + (2*2.74%*(overnights/365)), and a printed table converts every overnight count from 0 to 365 into a credit percentage. Overnights are the average over two consecutive years under the current written parenting plan or court order. Where a parent regularly has the child for long stretches without an overnight, '12 continuous hours may be counted as one day' and blocks of four to twelve hours may count as half-days, but never more than one full day per 24-hour period.
Use the state’s own calculator, not ours
Oregon publishes this itself, free. It is called Oregon Child Support Guidelines Calculator (online), with a Guidelines Calculator Workbook in Excel and printable Guidelines Worksheets and Instructions publish. We are not going to build a competing calculator and ask you to trust it — this is the one a judge will recognize.
Open the Oregon calculator →What goes into the calculation
What counts as income
'Income' means actual or potential gross income, and the two can be combined when a parent has some earnings but is working below capacity. Actual income includes 'salaries, wages, commissions, advances, bonuses, dividends, recurring overtime pay, severance pay, pensions, and honoraria,' expense reimbursements and in-kind payments 'to the extent they reduce personal living expenses,' annuities, trust income, interest, dividends, income replacement benefits including Social Security, workers' compensation, unemployment and VA disability, and inheritances, gifts and prizes including lottery winnings. On overtime the commentary is precise: 'Overtime is included to the extent it is regularly occurring. Sporadic overtime is not generally included. Overtime is calculated based on an annual amount, prorated over a 12-month period.' Employer contributions to medical benefits beyond the cost of coverage, and cash you receive for opting out of a health plan, count as income. For a service member, income includes housing and subsidy allowances.
When a judge can treat you as earning more
'Potential income' means 'the parent's ability to earn based on relevant work history, including hours typically worked by or available to the parent, occupational qualifications, education, physical and mental health, employment potential in light of prevailing job opportunities and earnings levels in the community, and any other relevant factors.' Oregon's commentary pushes back hard on lazy imputation: it 'is not intended to authorize automatically imputing full time minimum wage when someone has never consistently earned that level of income. Imputing full time minimum wage to parents who have never earned at that level is disfavored and likely to result in uncollectible debt.' It gives worked examples – a restaurant worker who cannot get more than 32 hours should not be charged with 40, while a professional who left a lucrative career may fairly be charged with what they could earn now in that field. If minimum wage is used, the rule directs the court to 'the lowest minimum wage provided for in any area of Oregon.'
If you do not earn much
Two protections. The self-support reserve is $1,729, subtracted from the paying parent's adjusted income to find what is available for support; that parent's total obligation 'may not exceed the parent's available income.' The reserve is 'based on the federal poverty guideline for a single person, multiplied by 1.303,' reviewed and updated annually – the current figure carries an effective date of July 1, 2026. The floor: 'it is rebuttably presumed that an obligated parent is able to pay at least $100 per month as child support.' The $100 minimum does not apply where each parent has exactly 182.5 overnights, where only medical support is ordered, where the order is suspended, or where the parent's sole income is disability benefits, the parent is an incarcerated obligor, or the parent receives public benefits.
Childcare and health insurance
Child care is adjusted for only 'if the child for whom support is being calculated is disabled or under the age of 13,' must be tied to employment, job search, or training or education needed to get a job, and must be documented actual cost. Oregon then caps it by table: for a provider in the Portland, Bend, Eugene, Corvallis, Springfield, Monmouth or Ashland metro areas, the maximum per child is $1,705 a month from newborn to age 3, $1,400 from 3 to 6, and $1,100 from 6 up; elsewhere in Oregon or out of state the caps are $1,190, $1,083, $860 and $629 respectively. Higher state day-care allowance figures may be used where they exceed these. The basic support obligation already includes ordinary unreimbursed medical costs; health insurance and cash medical support are handled under OAR 137-050-0750.
Private school, special needs, activities
There is no separate private-school line. Special expenses come in through the rebuttal criteria in OAR 137-050-0760 and ORS 25.280, which include 'the needs of the child,' 'the special hardships of a parent,' and other economic factors that directly affect the needs and best interests of the children. The list is not exclusive.
When a judge can depart from the number
The guideline amount is presumed correct. The presumption 'may be rebutted by a finding that sets out the presumed amount, concludes that it is unjust or inappropriate, and sets forth a different amount and a reason it should be ordered.' The criteria include other available resources of the parent, the parent's reasonable necessities, net income after required withholding, ability to borrow, the number and needs of other dependents, special hardships, the needs of the child, the desirability of a parent staying home, tax consequences, and the financial advantage from a new spouse or partner's income. The party seeking to rebut carries the burden.
Two things worth knowing. First, Oregon can order support for a child in college, up to age 21, and the adult child is a party in their own right – they can go to court about it themselves. Second, Oregon caps how much day care can go into the calculation by region and child age, so if you pay above the cap in a metro area, the extra is on you unless the judge departs from the formula.
Later on
When it ends
Support runs to 18. It can continue for a 'child attending school,' defined in ORS 107.108 as a child of the parties who 'is unmarried,' 'is 18 years of age or older and under 21 years of age,' 'is making satisfactory academic progress as defined by the school that the child attends,' and has 'a course load that is no less than one-half of the load that is determined by the school to constitute full-time enrollment.'
College and support after 18
Yes, and this is one of Oregon's distinctive features. 'School' under ORS 107.108 covers 'a high school, community college, four-year college or university,' 'a course of professional, vocational or technical training, including the Job Corps,' and high school equivalency programs including GED and home schooling. A support order 'may require either parent, or both of them, to provide for the support or maintenance of a child attending school,' and the adult child is a party to the proceeding – they can apply for services, ask for a modification, and participate in one.
Changing the amount later
Two separate routes. Anytime: 'proceedings may be initiated at any time to modify a support obligation based upon a substantial change of circumstances.' Periodic: the child support program may seek modification to bring an order into line with the formula once 'three years have elapsed, or such shorter cycle as determined by rule of the Department of Justice,' from the order, the last modification, or the last review, and in that proceeding the court 'shall modify the support order … regardless of whether there has been a substantial change in circumstances.' Note one trap: 'changes to these rules do not constitute a substantial change in circumstances for purposes of modifying a support order' – a new guidelines table alone is not a reason to reopen your case.
How far back a change can reach
We could not confirm Oregon's rule on the effective date of a modification from an official source, so nothing is stated here. File as soon as your circumstances change.
If someone stops paying
The Oregon Department of Justice Child Support Program administers collection and publishes an income withholding calculator. We did not confirm license-suspension or interest-on-arrears rules on an official source.
What we could not confirm
- We could not confirm from an official source how far back an Oregon modification reaches, or the state's official enforcement tools such as license suspension and interest on arrears. Ask the Child Support Program or your lawyer.
Compare all fifty states
The overnight thresholds, the ending ages and the college rules, side by side.
The rest of what we have written about Oregon. Every figure is quoted from Oregon’s own statute or its courts’ own published schedule, and carries the date we last checked it.