Child Support in Washington: How the Number Is Calculated, Limited, and Changed

People often ask for 'the child support calculator' as if Washington had a single public number that pops out of a website. What the law actually requires is more specific: both parents' household finances are disclosed, official worksheets are completed under penalty of perjury, and the court (or an administrative law judge) sets a transfer payment using the Washington State Child Support Schedule. The Division of Child Support worksheet calculator is a useful estimate. It is not the order.

This guide is written for Pierce County and Puyallup parents who need the 2026 framework — including the January 1, 2026 updates in RCW 26.19.065 — not a slogan about 'combined income.' It walks through how the number is built, what can be added or taken off, when the court may deviate, how temporary orders work during a case, when support ends, and how modification differs from a two-year adjustment. It is general education, not a prediction of your worksheet.

Support Is a Parenting Function — Not a Bargaining Chip

Both legal parents owe financial support. That duty exists in a divorce, a parentage case, a parenting-plan case, and even when the parents never married. RCW 26.09.002 treats residential time and financial support as both important, and they are not supposed to be traded against each other. If one parent misses overnights, the other parent still owes support. If support is late, the other parent still has to follow the parenting plan. Unpaid support is collected through support tools and, when appropriate, contempt — not by withholding the child.

RCW 26.19.035 makes the schedule apply in every county, in court and administrative cases, for temporary and final orders, and for modifications. Incomplete worksheets, or homemade spreadsheets that do not match the Administrative Office of the Courts form, are not supposed to be accepted. The order must state both the standard calculation and the amount actually ordered, and it must include written findings if the court grants or denies a deviation.

How the Worksheets Build the Number

Think of the worksheet as a sequence, not a negotiation. First each parent lists monthly gross income. Then allowed deductions produce monthly net income. Those two nets are added together. The economic table in RCW 26.19.020 converts combined net income and the number of children into a basic support obligation — usually a higher figure for children 12 through 17 than for children 0 through 11. Each parent is then assigned a percentage share equal to that parent's share of combined net income. The parent who has the child less of the time (the parent making the transfer payment) typically pays their share to the other parent. Health care premiums, day care, and certain extra costs are layered on after that.

1. Disclose and verify income (generally two years of tax returns and current paystubs)
2. Convert gross monthly income to net monthly income using only the deductions the statute allows
3. Add the parents' nets and look up the basic obligation on the economic table
4. Split that basic obligation in proportion to each parent's net income
5. Apply the self-support reserve, $50-per-child minimum, and 45% cap where they fit
6. Allocate health care, day care, and special child-rearing expenses in the same proportions
7. Consider deviations only after the standard calculation is on the page, with written findings

A short example from the official schedule instructions shows the proportions. If combined monthly net income is $8,500 and Parent 1 nets $3,500 (about 41%) while Parent 2 nets $5,000 (about 59%), each parent's share of the table amount follows those percentages. The transfer payment is not 'half of everything' and it is not 'whatever is left after the mortgage.'

What Counts as Income — and What Must Be Disclosed but Left Out

RCW 26.19.071 starts with a broad rule: all income and resources of each parent's household shall be disclosed and considered. Only the parents' own income is used to calculate the basic support obligation. A new spouse's paycheck, a boyfriend's overtime, or a grandparent's rent contribution is not plugged into the table as if it were Parent 1's wages.

Gross monthly income includes, among other sources, salaries, wages, commissions, overtime (with a narrow exception), second jobs, bonuses, self-employment and rental income, dividends and interest, pensions, workers' compensation, unemployment, Social Security, disability insurance, maintenance actually received, and deferred compensation. Self-employed parents do not get to pick a number that looks tidy on a Schedule C; normal business expenses can be deducted, but disputed write-offs have to be justified.

Some items must still be disclosed even though they are excluded from gross income: income of a new spouse, new domestic partner, or other adults in the household; child support received for children of other relationships; gifts and prizes; TANF; SSI; aged, blind, or disabled assistance; pregnant-women assistance; and food stamps. Receipt of TANF, SSI, ABD, or food stamps is not a reason to deviate from the standard calculation. Overtime or second-job income beyond 40 hours a week, averaged over 12 months, can also be excluded when it was worked to support a current family or to pay off past-relationship or support debt, and the court finds that income will stop when the debt is gone.

Net Income: Taxes, PFML, WA Cares, and Retirement

Net income is not take-home pay after every automatic deduction on a paystub. The statute lists what may be subtracted: federal and state income taxes, FICA, mandatory pension contributions, mandatory union or professional dues, mandatory state insurance premiums actually paid — including Paid Family and Medical Leave and the long-term services and supports (WA Cares) premium — industrial insurance, court-ordered maintenance actually paid, up to $5,000 a year in voluntary retirement contributions if there is a one-year pattern and the contributions were not made to suppress support, and normal self-employment expenses and self-employment taxes. Extra 401(k) withholding, a car payment run through payroll, or an aggressive W-4 that withholds more tax than will actually be owed does not automatically shrink the support number.

The 2026 Economic Table, Self-Support Reserve, and Caps

The 2025 Legislature rewrote the floors and ceilings, effective January 1, 2026. Under RCW 26.19.065, the economic table is presumptive for combined monthly net incomes from $2,200 through $50,000. Above $50,000, the court may exceed the $50,000 table amount only with written findings. That expansion matters in the Puget Sound: many two-income households that used to sit in a discretionary zone now have a table number.

The self-support reserve rose from 125% to 180% of the federal poverty guideline for a one-person household. Using the 2026 HHS poverty guideline of $15,960 a year for one person, 180% is $28,728 a year, or $2,394 a month. That figure will move when federal poverty guidelines are updated. The basic support obligation of the parent making the transfer payment — excluding health care, day care, and special expenses — generally cannot reduce that parent's net income below this reserve, except for a presumptive minimum of $50 per child per month, or when applying the reserve would be unjust after looking at the child's basic needs, comparative hardship, assets, and earning capacity.

• Presumptive table: combined monthly net income $2,200 through $50,000
• Self-support reserve: 180% of the federal poverty guideline for a one-person household
• Presumptive minimum: $50 per child per month unless it would be unjust
• 45% cap: neither parent's support for all of that parent's biological or legal children may exceed 45% of that parent's net income except for good cause
• Good cause for exceeding the 45% cap can include substantial wealth, day-care costs, special medical or educational needs, and larger families

The 45% test is easy to miss if a parent already pays support in another case. Each child is entitled to a pro rata share of the income available for support, but the court only applies that share to the children in the case in front of it. Before applying the cap, the court has to consider whether doing so would leave the household that has the children without enough for basic needs.

Imputed Income When a Parent Is Not Working Full-Time

If a parent is voluntarily unemployed or voluntarily underemployed, the court shall impute income. 'Full-time' is not automatically 40 hours. RCW 26.19.011 defines it as the customary maximum non-overtime hours in that person's occupation, industry, and labor market. The court looks at assets, residence, work history, skills, education, health, age, criminal record, local employers, and other barriers. Income is not imputed to a parent who is unemployable, or to the extent a parent is out of work because of court-ordered reunification efforts in a dependency case. A parent who is already working full-time is not supposed to have extra income imputed unless the court finds the parent is purposely underemployed to reduce support.

When actual earnings records are missing, the statute sets an order of priority: current full-time rate of pay; historical full-time rate (Employment Security data is often used); a past rate when the history is patchy; 32 hours a week at local minimum wage in listed situations (recent TANF, SSI or similar benefits, recent incarceration, recent high-school graduate) as a rebuttable presumption; full-time minimum wage if that is the realistic history; and, last, census median income. A parent enrolled in high school full-time is a special case: if imputation is appropriate at all, the rebuttable presumption is 20 hours a week at local minimum wage.

Health Care, Day Care, and Costs the Table Does Not Include

The economic table is a basic support figure. It does not include health care or day care. RCW 26.19.080 says monthly health-care costs — medical, dental, orthodontia, vision, mental-health treatment, prescriptions, and similar care — are shared in the same proportion as the basic obligation. Day care and special child-rearing expenses, such as tuition or long-distance transportation for residential time, are shared the same way. The court still has discretion to decide whether amounts above the basic obligation are necessary and reasonable, and whether a parent can actually pay them.

If a parent is ordered to pay day care that is not actually incurred, and the overpayment reaches 20% of that parent's annual day-care or special-expense obligation, the other parent must reimburse. Reimbursement first offsets any support arrears; otherwise it can be a direct repayment or a credit spread over 12 months. A parent cannot unilaterally overpay extras and then dock the monthly transfer payment.

Deviations: New-Spouse Income, Overnights, and Other Children

A deviation is a number different from the standard calculation. RCW 26.19.075 lists reasons that include, but are not limited to, wealth, extraordinary income of a child, nonrecurring bonuses or overtime (looking back two calendar years), extraordinary involuntary debt, special needs, tax planning that does not leave the child worse off, children from other relationships, and a residential schedule in which the child spends significant time with the parent who would otherwise write the check.

Two rules surprise people. First, income of a new spouse, new domestic partner, or other adult in the household is not, by itself, a reason to deviate. It can be considered only if the parent who lives with that adult is already asking for a deviation for some other listed reason. Second, agreement of the parties is not by itself an adequate reason to deviate. Parents can settle, and courts often enter agreed orders — but the worksheets still have to be done, the standard calculation still has to appear, and the judge still has to find a legally recognized basis if the transfer payment leaves the table amount.

Residential-schedule deviations are also narrower than 'we do 50/50, so nobody pays.' The court may reduce the transfer payment when the child spends significant time with the paying parent, but not if that would leave the other household without enough for the child's basic needs, and not if the child is on TANF. The court is supposed to look at increased costs in the paying parent's home and decreased costs, if any, in the receiving parent's home — not simply split the table number in half because the overnights look even on a calendar.

Children from other relationships are not added into the headcount on the table for this case. The court calculates the presumptive amount as if only the children before it exist, then may deviate after looking at support actually paid for other children and the total circumstances of both households. Unpaid 'paper' obligations in another case do not automatically shrink this one.

Temporary Support While a Case Is Pending

Families still have to eat and keep the lights on before a final decree. Either parent can ask for temporary child support in a divorce, legal separation, or parentage case, typically through a motion for temporary orders. The same schedule applies. Temporary support lasts until a later temporary order or the final order replaces it. In Pierce County those motions are commonly heard on a commissioner's calendar at Pierce County Superior Court in Tacoma, even when the family lives in Puyallup, South Hill, or another East Pierce city.

When Support Ends — and Post-Secondary Help for College or Trade School

Unless the order or a written agreement says otherwise, RCW 26.09.170 terminates future child support on emancipation of the child or on the death of the person required to pay. For most children, emancipation is age 18. If the child is still in high school, a parent can seek a one-year-or-later modification to extend support through graduation without proving a substantial change of circumstances. Support also ends if the parents of a parentage or dissolution order marry (or register a domestic partnership) to each other, unless the court order says otherwise.

College or vocational support is a different question. RCW 26.19.090 makes the child-support schedule advisory, not mandatory, for post-secondary educational support. The court first decides whether the child is actually dependent and relying on the parents for the reasonable necessities of life. It then weighs age, needs, the parents' expectations when they were together, the child's prospects and abilities, the program sought, each parent's education and resources, and what the child would have received if the family had stayed intact. Support is not supposed to be ordered past the child's 23rd birthday except in exceptional circumstances such as a disability.

If post-secondary support is ordered, the student generally must enroll in an accredited academic or vocational school, stay in good standing, pursue a course of study that matches those goals, and give both parents access to grades and records. The obligation suspends automatically during periods of noncompliance. Payments are directed to the school when that is feasible. Timing is unforgiving: a petition usually has to be filed before the current child-support order ends — before the 18th birthday if that is the termination date, or before high school graduation if the order lasts that long. Many orders 'reserve' post-secondary support when the children are young. A reservation is not an automatic college order. It still requires a later, timely petition. Waiting until move-in weekend is how the issue is lost.

Changing the Number: Modification Versus a 24-Month Adjustment

Unpaid months already due generally stay due. Modifications and adjustments usually reach only installments that come due after the petition or motion is filed. A parent who lost a job in January and waits until October to file does not automatically wipe out the winter and spring arrears.

A true modification can be requested at any time based on a substantial change of circumstances. Voluntary unemployment or underemployment, by itself, is not that change. After an order has been in place for at least a year, a parent can also seek modification without a substantial-change showing if the order works a severe economic hardship, if a child needs support past 18 to finish high school, or to add an automatic-adjustment provision. Incarceration of the paying parent has its own abatement path under RCW 26.09.320.

If 24 months have passed since the order (or the last adjustment or modification), either parent may file a motion — not a full modification petition — to adjust the amount based on current incomes or based on changes to the economic table and standards in Chapter 26.19 RCW. That last route matters in 2026: an order entered on the old table can be adjusted to the new $50,000 table and 180% reserve without proving that someone's life fell apart. If the adjustment changes the obligation by more than 30% and would cause significant hardship, the court may phase it in as two equal steps six months apart.

The Department of Social and Health Services can also file to modify or adjust when public assistance is being paid for the child, or in a non-assistance case if a party requests a review, the case meets DCS criteria, and the current order is at least 15% above or below the standard calculation. The Pierce County Prosecuting Attorney's Family Support Division handles some of those state-referred cases. The prosecutor represents the State, not either parent. The petition-versus-adjustment choice, the filing-date rule for arrears, DCS screens, incarceration abatement, and Pierce County forms are covered in a dedicated child support modification guide.

If the Order Is Not Being Paid

A support order is not self-executing. Most orders include immediate income withholding. The Division of Child Support can collect through employers, intercept tax refunds, report to credit agencies, and pursue license and other administrative remedies. Parents can also ask the superior court for contempt when a parent has the ability to pay and willfully does not. Ability to pay is the fight in many contempt hearings: a parent who lost hours at JBLM-area contractors or at a warehouse in Fife is in a different position from a parent who quit a job to squeeze the worksheet. Public defenders can be appointed for the obligated parent in contempt because jail is on the table. Withholding residential time is still not a lawful collection method.

Pierce County Practice: Forms, Facilitators, and Where It Is Heard

Most Puyallup, South Hill, Sumner, and Tacoma support cases are filed in Pierce County Superior Court. Child-support modifications and many state-filed adjustments are heard in Civil Division C. Official pattern forms — including a Petition to Modify Child Support Order (FL Modify 501) and a Motion to Adjust Child Support Order (FL Modify 521) — are on the Washington Courts family-law forms page. The current WSCSS schedule, instructions, and worksheets (effective January 1, 2026) are mandatory.

The Pierce County Clerk publishes a support-only modification checklist. As of the clerk's posted information, the filing fee is lower when you already have a Pierce County case than when you are opening a new one, and fee waivers are available. Court facilitators can review forms by appointment (a small fee applies) but cannot give legal advice. Self-represented parents can also use DCS if they have an open full-enforcement case and want the agency to review whether an adjustment or modification is appropriate. An attorney is often worth it when income is from self-employment or overtime, when imputation is disputed, when a 50/50 residential schedule is being used to argue for a large deviation, or when post-secondary support is coming due.

A child-support order is a monthly cash-flow document that has to survive real Pierce County life — school-year day care, a swing shift, a second job that was only meant to pay off a car, a deployment-related drop in BAH. If you are setting support for the first time, responding to worksheets you do not trust, or trying to bring an old order onto the 2026 schedule, talking with a Puyallup family law attorney early is how you avoid locking in a number that the statute never required.