Child support in Washington.
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 stateWashington
Washington combines both parents' monthly net incomes, reads the basic support obligation off an economic table, and allocates it between the parents 'based on each parent's share of the combined monthly net income.' Health care costs, day care and special expenses sit outside the table and are shared in the same proportion. Two ceilings protect the paying parent, and there is a firm floor.
How Washington works out the number
Authority: RCW chapter 26.19 (Child Support Schedule), including RCW 26.19.020 (economic table), 26.19.065 (upper and lower limits), 26.19.071 (income standards), 26.19.075 (deviation), 26.19.080 (allocation, day care and special expenses), and 26.19.090 (postsecondary support). Several key provisions were amended by ESHB 1014 (2025), with the revised economic table effective January 1, 2026.There is no overnight threshold and no automatic formula. Under RCW 26.19.075(1)(d), 'the court may deviate from the standard calculation if the child spends a significant amount of time with the parent who is obligated to make a support transfer payment.' But there is a hard limit: 'the court may not deviate on that basis if the deviation will result in insufficient funds in the household receiving the support to meet the basic needs of the child or if the child is receiving temporary assistance for needy families.' The judge must weigh the increased expenses to the paying parent and the decreased expenses, if any, to the receiving parent.
Use the state’s own calculator, not ours
Washington publishes this itself, free. It is called WSCSS – Schedule (Washington State Child Support Schedule: definitions, standards, instructions and economic table) and WSCSS – Worksheets, revised 06/2026, pub. 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 Washington calculator →What goes into the calculation
What counts as income
RCW 26.19.071(3) lists gross monthly income as including salaries, wages, commissions, deferred compensation, 'overtime, except as excluded,' contract-related benefits, 'income from second jobs, except as excluded,' dividends, interest, trust income, severance pay, annuities, capital gains, pensions, workers' compensation, unemployment, maintenance actually received, bonuses, Social Security, disability benefits, and 'income from self-employment, rent, royalties, contracts, proprietorship of a business, or joint ownership of a partnership or closely held corporation.' The exclusion is narrow and specific: 'overtime or income from second jobs beyond 40 hours per week averaged over a 12-month period worked to provide for a current family's needs, to retire past relationship debts, or to retire child support debt, when the court finds the income will cease when the party has paid off his or her debts.' Also excluded: a new spouse's income, other adults' income in the household, child support from other relationships, gifts and prizes, TANF, SSI, food stamps. Deductions to reach net income include income taxes, FICA, mandatory pension payments, mandatory union or professional dues, state paid family and medical leave and long-term care premiums, industrial insurance, court-ordered maintenance actually paid, 'up to $5,
When a judge can treat you as earning more
'The court shall impute income to a parent when the parent is voluntarily unemployed or voluntarily underemployed,' judged on assets, residence, employment and earnings history, job skills, education, literacy, health, age, criminal record, dependency court obligations, employment barriers, record of seeking work, the local job market, the availability of willing employers, and prevailing local earnings. Two protections: 'a court shall not impute income to a parent who is gainfully employed on a full-time basis, unless the court finds that the parent is voluntarily underemployed and finds that the parent is purposely underemployed to reduce the parent's child support obligation,' and 'income shall not be imputed for an unemployable parent.' Where records are missing, the statute sets a strict order of priority: full-time earnings at the current rate of pay; then at the historical rate; then at a past rate; then 32 hours a week at minimum wage for a parent coming off public assistance, recently released from incarceration, or a recent high school graduate; then full-time minimum wage; then the census median for full-time year-round workers. A parent still enrolled full time in high school is imputed at 20 hours a week at minimum wage if imputed at all.
If you do not earn much
Washington's self-support reserve is 180% of the federal poverty guideline for a one-person family, and as of January 13, 2026 the Administrative Office of the Courts publishes that figure as $2,394 per month – up $764 from the $1,630 that applied from January 15, 2025 through January 12, 2026. The presumptive minimum is separate: 'when a parent's monthly net income is below 180 percent of the federal poverty guideline for a one-person family, a support order of not less than $50 per child per month shall be entered unless the obligor parent establishes that it would be unjust to do so.' There is also a hard ceiling: 'neither parent's child support obligation owed for all his or her biological or legal children may exceed 45 percent of net income except for good cause shown.' At the top end, 'the economic table is presumptive for combined monthly net incomes up to and including $50,000.'
Childcare and health insurance
Neither is inside the economic table. 'Monthly health care costs shall be shared by the parents in the same proportion as the basic child support obligation,' covering medical, dental, orthodontia, vision, chiropractic, mental health treatment and prescriptions. 'Day care and special child rearing expenses, such as tuition and long-distance transportation costs to and from the parents for visitation purposes, are not included in the economic table [and] shall be shared by the parents in the same proportion as the basic child support obligation.' There is a real refund right: if you pay court-ordered day care or special expenses that are not actually incurred, and the overpayment 'amounts to at least 20 percent of the obligor's annual day care or special child rearing expenses,' you can go to court or to DSHS to get it back, applied first against any arrears.
Private school, special needs, activities
Deviation is allowed for 'extraordinary debt not voluntarily incurred,' 'a significant disparity in the living costs of the parents due to conditions beyond their control,' 'special needs of disabled children,' and 'special medical, educational, or psychological needs of the children.' Private school tuition also appears as a 'special child rearing expense' shared proportionally under RCW 26.19.080(3).
When a judge can depart from the number
'Unless specific reasons for deviation are set forth in the written findings of fact and are supported by the evidence, the court shall order each parent to pay the amount of support determined by using the standard calculation.' The court must enter findings specifying reasons for any deviation and for any denial of a requested deviation, and must determine the standard calculation before considering reasons to depart. One rule worth knowing before you settle: 'agreement of the parties is not by itself adequate reason for any deviations from the standard calculation.'
Two things stand out for 2026. First, the self-support reserve jumped from $1,630 to $2,394 a month on January 13, 2026, because the legislature moved it from a lower multiplier to 180% of the federal poverty level effective January 1, 2026 – if your order was set before then, a recalculation could look very different. Second, Washington will order parents to help pay for college up to the child's 23rd birthday, which is rare, and the child has to keep their grades up and share their transcripts to keep it.
Later on
When it ends
'Unless otherwise agreed in writing or expressly provided in the decree, provisions for the support of a child are terminated by emancipation of the child or by the death of the person required to pay support.' Washington also allows an order to be modified a year or more after entry, without any change in circumstances, 'if a child is still in high school, upon a finding that there is a need to extend support beyond the eighteenth birthday to complete high school.'
College and support after 18
Yes, and Washington is unusually explicit about it. RCW 26.19.090 makes the schedule 'advisory and not mandatory for postsecondary educational support.' The court must first determine 'whether the child is in fact dependent and is relying upon the parents for the reasonable necessities of life,' then weigh the child's age, needs, prospects, aptitudes and disabilities, the nature of the education sought, the parents' education and standard of living, and 'the amount and type of support that the child would have been afforded if the parents had stayed together.' The child must be enrolled in an accredited academic or vocational school, actively pursuing a course of study, and in good academic standing, and must share academic records with both parents; support is 'automatically suspended' if they stop meeting those conditions. Hard stop: 'the court shall not order the payment of postsecondary educational expenses beyond the child's twenty-third birthday, except for exceptional circumstances, such as mental, physical, or emotional disabilities.'
Changing the amount later
Three routes. Anytime, on 'a showing of substantially changed circumstances' – but note that 'the voluntary unemployment or voluntary underemployment of the person required to pay support, by itself, is not a substantial change of circumstances.' After 24 months from entry or the last adjustment, an order 'may be adjusted without a showing of substantially changed circumstances' based on income changes or 'changes in the economic table or standards in chapter 26.19 RCW.' And the Division of Child Support may file to modify where it determines the order 'is at least fifteen percent above or below the appropriate child support amount set forth in the standard calculation.' If an adjustment changes support by more than 30% and would cause significant hardship, the court may phase it in over six months.
How far back a change can reach
A support order may be modified 'only as to installments accruing subsequent to the petition for modification or motion for adjustment.' In plain terms, nothing changes for the months before you file – so file the petition, do not wait.
If someone stops paying
The DSHS Division of Child Support administers enforcement and publishes the automated worksheet and estimator tools. Support can be abated to ten dollars per month per order while a paying parent is incarcerated, under RCW 26.09.320, and an order can be modified to add that abatement language at any time. We did not confirm license-suspension or interest-on-arrears details on an official source.
What we could not confirm
- We could not confirm Washington's license-suspension and interest-on-arrears rules from an official source. Ask the Division of Child Support.
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 Washington. Every figure is quoted from Washington’s own statute or its courts’ own published schedule, and carries the date we last checked it.