Washington uses an income shares model with a published economic table. Both parents’ incomes are combined, and a transfer payment is calculated based on income share and residential schedule.
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Washington calculates child support using the Income shares model with economic table established under RCW 26.19. This is a statutory formula that leaves limited room for judicial discretion on the base calculation amount, ensuring consistency and predictability for families across the state.
Basic obligation from economic table based on combined income and children. Transfer payment between parents based on income share and residential schedule.
The calculation begins with determining each parent's net disposable income, which includes virtually all sources of income minus taxes, mandatory payroll deductions, and certain hardship deductions. The court then applies the statutory formula using the time each parent has primary physical responsibility for the children and the applicable income allocation brackets.
Beyond the base formula amount, Washingtonrequires additional contributions for mandatory add-on expenses. These typically include childcare costs necessary for the custodial parent's employment or education, uninsured healthcare expenses for the children, and in some cases, educational and travel costs. These add-ons are split between parents in proportion to their respective incomes.
Primary statute: RCW 26.19
2026 HB 1014 reform: combined income cap raised to $50,000/month ($600,000/year) with expanded economic table.
Standard calculation uses both parents’ incomes, number of children, and residential schedule.
Health insurance and childcare added, split proportionally.
Transfer payment calculated between parents based on income share and residential time.
2026 HB 1014 significantly expanded the economic table and raised the income cap.
WA state pensions (PERS/TRS/LEOFF/WSPRS) require DRS property division orders, not QDROs.
2026 HB 1014: combined income cap raised to $50,000/month with expanded economic table.
Answer a few questions about your income, custody, and children. Get your personalized estimate.
Residency Requirement
No residency requirement for filing (unique among states)
Mandatory Waiting Period
90-day waiting period after filing (RCW 26.09.030)
No-Fault Ground
Irretrievable breakdown ("without regard to misconduct")
State Income Tax
No state income tax
Washington uses the Income shares model with economic table under RCW 26.19. Washington uses an income shares model with a published economic table. Both parents’ incomes are combined, and a transfer payment is calculated based on income share and residential schedule.
Key factors include both parents' income, the number of children, custodial time share, mandatory add-on expenses (childcare, health insurance), and any applicable deductions. 2026 HB 1014 reform: combined income cap raised to $50,000/month ($600,000/year) with expanded economic table.
Yes. Either parent can request a modification if there has been a material change in circumstances, such as a significant change in income, custody arrangements, or the needs of the child. The court will recalculate support using the same statutory formula.
Basic obligation from economic table based on combined income and children. Transfer payment between parents based on income share and residential schedule.
Get a personalized child support calculation based on Washington's actual statutory formula.
Start My Free WashingtonEstimate →This tool provides educational estimates based on Washington family law and does not constitute legal advice. Child support calculations are approximations of the statutory formula and may differ from court-ordered amounts. Consult a licensed Washington family law attorney before making decisions. Primary statute: RCW 26.19.