In Washington, 50/50 custody does not eliminate child support. Under RCW 26.19.020, courts apply the income-shares formula to both parents' combined net income, then a higher earner typically still pays. A residential-schedule deviation under RCW 26.19.075 may reduce the amount when a child spends 91-plus overnights annually with the paying parent.
Key Facts: Washington Child Support and Divorce
The table below summarizes the core procedural and financial facts that govern child support and divorce filings in Washington as of March 2026. Each figure is drawn from Chapter 26.09 RCW (dissolution) and Chapter 26.19 RCW (child support), which together control residency, timing, grounds, and the support calculation. These baseline numbers apply statewide, though county clerks set the exact filing fee within a narrow range. Verify any fee with your local Superior Court clerk before filing.
| Factor | Washington Rule (2026) |
|---|---|
| Filing Fee | $314-$364 depending on county. As of March 2026. Verify with your local clerk. |
| Waiting Period | 90 days from filing and service (RCW 26.09.030); cannot be waived |
| Residency Requirement | No minimum duration; petitioner or spouse must be a Washington resident (RCW 26.09.030) |
| Grounds | No-fault only: marriage is irretrievably broken (RCW 26.09.030) |
| Property Division Type | Community property; just and equitable division (RCW 26.09.080) |
| Support Model | Income Shares Model (RCW 26.19.020) |
| Deviation Threshold | More than 90 overnights/year with paying parent (RCW 26.19.075) |
Does 50/50 Custody Eliminate Child Support in Washington?
No. A 50/50 parenting schedule does not automatically eliminate or reduce child support in Washington. Under RCW 26.19.020, courts run the full income-shares calculation regardless of overnight split, and the higher-earning parent typically still pays support. Equal time does not mean equal financial resources, so an obligation usually remains when incomes differ.
This surprises many parents who assume equal parenting time cancels the payment. The reason child support 50 50 custody Washington cases still produce an obligation is that Washington's guidelines focus on the child's right to share in both parents' standard of living, not on counting overnights alone. A child who lives in a higher-income home half the time and a lower-income home the other half would experience two very different standards without support. The court's goal is to ensure both households can meet the child's basic needs. Even in shared custody child support arrangements, the income disparity between parents drives the result far more than the residential schedule. To change the presumptive amount, a parent must affirmatively request a deviation under RCW 26.19.075 and prove it with financial documentation.
How Washington Calculates Child Support: The Income Shares Model
Washington uses the Income Shares Model under RCW 26.19.020. Courts combine both parents' monthly net incomes, locate the basic support obligation on the statutory economic table, then divide that obligation proportionally by each parent's share of combined income. A parent earning 60% of combined net income pays 60% of the basic obligation, plus 60% of add-on expenses like health insurance and childcare.
The calculation proceeds in four steps. First, each parent's net income is computed by deducting federal taxes, FICA (Social Security and Medicare), mandatory pension and union dues, L&I premiums, and up to $5,000 in annual voluntary retirement contributions from gross income. As of January 1, 2026, parents may also deduct mandatory state insurance premiums actually paid, including Paid Family and Medical Leave and the WA Cares long-term-care program. Second, the two net incomes are combined. Third, the combined figure and the number of children are matched to the basic obligation on the economic table in RCW 26.19.020. Fourth, the obligation is split by income share. This same equal custody child support method applies whether parenting time is 90/10 or a true 50/50 split, because the schedule affects only deviation, not the underlying formula.
The 2026 Economic Table Overhaul: EHB 1014
Washington enacted its largest child support reform in over a decade through Engrossed House Bill 1014, effective January 1, 2026. The law quadrupled the economic table's combined-income cap from $12,000 to $50,000 per month, raised the self-support reserve from 125% to 180% of the federal poverty level, and added new deductions. These changes apply to every child support order entered or modified on or after January 1, 2026.
EHB 1014 amended RCW 26.19.020, 26.19.065, 26.19.071, and 26.19.080. Before 2026, the economic table stopped at $12,000 in combined monthly net income, forcing judges to use broad discretion for higher-income families and producing inconsistent outcomes. The new table is presumptive for combined incomes up to and including $50,000 per month. For combined incomes between $2,200 and $12,000, the support amounts remain unchanged from the prior table, so most middle-income families see no difference. For incomes above $12,000, new amounts are set by an economic formula rather than older spending studies. When combined monthly net income exceeds $50,000, RCW 26.19.065 permits the court to exceed the presumptive $50,000-level amount only upon written findings of fact. Washington also became the first state to recognize paid-leave program deductions in the calculation.
The Residential Schedule Deviation: How 50/50 Time Can Lower Support
A parent with a 50/50 schedule can request a residential-schedule deviation under RCW 26.19.075 to reduce the standard obligation. The threshold is more than 90 overnights per year (25% of overnights) with the parent who would otherwise pay support. Deviation is discretionary, not automatic, and the court must enter written findings explaining any reduction. A 50/50 split alone does not guarantee a lower amount.
This is the central mechanism for shared custody child support in Washington. Unlike states with a built-in shared-parenting formula, Washington requires the paying parent to specifically ask for the deviation and to document the increased costs of maintaining the child in two homes. Courts grant residential deviations sparingly because they presume the guideline amount is correct. Two important limits apply under RCW 26.19.075: a deviation cannot be granted if the child receives public assistance, and it cannot be granted if the reduction would leave the receiving household without enough resources to meet the child's basic needs. The larger the income gap between parents, the less likely a full deviation is, because the court prioritizes equalizing the child's standard of living across both homes. Parents asking "do I still pay child support with joint custody" in Washington should expect to pay something unless they meet this threshold and persuade the court.
Income Limits: Maximum Obligation and Self-Support Reserve
Washington caps the total child support obligation at 45% of a parent's net income for all of that parent's biological or legal children, except for good cause shown under RCW 26.19.065. The self-support reserve, raised to 180% of the federal poverty level effective January 1, 2026, protects low-income payers; that floor is approximately $2,347 per month for a one-person household in 2026.
These guardrails matter in 50/50 cases involving lower-income parents. Under the 2026 version of RCW 26.19.065, when a parent's net income is below 180% of the federal poverty guideline for one person, the court enters a minimum order of no less than $50 per child per month unless the parent proves that amount would be unjust. When a parent's income sits above the self-support reserve, the basic obligation cannot push that parent's income below the reserve, except for the presumptive $50-per-child minimum. The 45% cap prevents a parent supporting several children across different relationships from being assigned an unworkable total. Together, these limits show that 50/50 parenting time support is shaped by income protections as much as by the residential schedule, and that the floor and ceiling apply regardless of how overnights are divided.
Add-On Expenses: Health Insurance, Childcare, and Medical Costs
Beyond the basic obligation, Washington requires parents to share specific add-on expenses proportionally by income under RCW 26.19.080. These include health insurance premiums, uninsured or out-of-pocket medical costs, and work-related childcare. A parent responsible for 55% of combined income pays 55% of these costs, separate from the basic support figure on the economic table.
In a 50/50 arrangement, add-ons are frequently the practical battleground because the basic obligation may be reduced by a deviation while these mandatory costs remain split by income share. Under RCW 26.19.080, health insurance premiums covering the child, day care necessary for employment or education, and uninsured medical expenses are allocated between parents in proportion to their net incomes. The 2026 EHB 1014 changes removed routine educational expenses from the economic table, meaning some education-related costs are now handled separately rather than baked into the base figure. Extraordinary expenses, such as private school tuition, special medical needs, or long-distance transportation for parenting time, can also be allocated proportionally when the court finds them reasonable and necessary. Parents in equal-time arrangements should document who pays each add-on so the court can credit those payments in the final order.
Modifying a Child Support Order in a 50/50 Case
Washington allows modification of a child support order under RCW 26.09.170 when there is a substantial change in circumstances. The threshold for an adjustment is a change that would alter the support obligation by at least 25% or $50 per month, whichever is greater. Orders may also be modified periodically, and the 2026 EHB 1014 reforms do not automatically apply to existing orders until they are modified.
Because the 2026 economic table only governs new and modified orders entered on or after January 1, 2026, parents with pre-2026 orders may consider whether seeking a modification helps or hurts their numbers under RCW 26.09.170. A meaningful shift in either parent's income, a change in the parenting schedule that crosses the 90-overnight deviation threshold, or a significant change in the child's needs can all support a modification petition. The substantial-change standard prevents constant relitigation: a small income fluctuation will not meet the 25%-or-$50 bar. Parents in 50/50 arrangements who experience a job loss, a raise, a new child, or a schedule change should run updated figures through the official Washington State Child Support Schedule worksheets before filing, because the post-2026 table may produce a materially different result than an older order.
Filing and Procedural Basics for Washington Divorce
A Washington dissolution requires no minimum residency duration: the petitioner or their spouse simply must be a Washington resident when filing, under RCW 26.09.030. The filing fee ranges from $314 to $364 depending on county, and a mandatory 90-day waiting period runs from the later of filing or service before any decree can be entered. Washington is a no-fault, community-property state.
The 90-day waiting period under RCW 26.09.030 is a cooling-off period, not a separation requirement; spouses may live together throughout. The clock starts on the later of two events: the date the petition is filed or the date the respondent is served, so delayed service can push the effective minimum past 90 days. Washington recognizes only one ground for divorce, that the marriage is irretrievably broken, and has eliminated all fault-based grounds. Fee waivers are available under court rule GR 34 for households at or below 125% of the federal poverty level. As of March 2026, King, Pierce, and Snohomish counties charge $314, while some smaller counties such as Lincoln charge $364. Always verify the current fee with your local Superior Court clerk and consult courts.wa.gov for the official WSCSS worksheets and dissolution forms before filing.