Washington State Child Support Guidelines and Filing

The Washington state child support guidelines set a presumptive monthly obligation by combining both parents’ net incomes, looking up the total on the economic table in RCW 26.19.020, and dividing that obligation between the parents in proportion to what each earns. The parent the child lives with most of the time is presumed to spend their share directly; the other parent pays their share as a transfer payment. As of January 1, 2026, the economic table applies to combined monthly net incomes from $2,200 up to $50,000, a substantial expansion from the previous $1,000 to $12,000 range.¹

How the Basic Calculation Works

Washington treats the two parents as a single economic unit for support purposes. Add both parents’ monthly net incomes together, find the row on the economic table that matches the combined figure, and read across to the column matching the number and ages of the children. That dollar amount represents what the family would typically spend on those children if the household were intact.¹

Each parent then owes a share of the total proportional to their own income. If one parent earns 60 percent of the combined net income, they are responsible for 60 percent of the table amount. The custodial parent’s share is assumed spent on daily expenses. The other parent writes the check.

The 2026 Table Expansion

Before January 1, 2026, the table only produced a presumptive amount up to $12,000 in combined monthly net income. Anything above that required the court to make case-by-case findings. The 2026 version pushes the ceiling to $50,000, so higher-earning families now get a presumptive number straight from the schedule. Below the new $2,200 floor, the court sets support based on each household’s actual resources and living costs rather than the table.

The Floor: Self-Support Reserve and Minimum Payment

The paying parent’s obligation cannot push their own net income below the self-support reserve, which equals 180 percent of the federal poverty guideline for a one-person household. Under the 2026 schedule that figure is $2,347.50 per month.² If the calculated payment would leave the paying parent below the reserve, the payment is reduced. A minimum obligation of $50 per child per month still applies unless the parent shows that amount would be unjust.³

What Counts as Income

The calculation begins with gross monthly income from all sources: wages, salaries, bonuses, commissions, self-employment revenue, interest, and other recurring money. From that gross figure, Washington allows specific deductions to arrive at the net income that goes into the table.

Federal income tax
FICA contributions for Social Security and Medicare
Mandatory pension payments
Mandatory union or professional dues
State industrial insurance premiums
Court-ordered spousal maintenance actually being paid
Voluntary retirement contributions up to $5,000 per year, if the parent made similar contributions in the two tax years before the case began
Ordinary business expenses and self-employment taxes for self-employed parents, with each expense justified

These deductions come from RCW 26.19.071, and each one has to be backed up with records.⁴

When Income Gets Imputed

A parent who is voluntarily unemployed or underemployed can have income imputed by the court. Judges follow a specific hierarchy: first, full-time earnings at the median for year-round workers in the parent’s age group from U.S. Census data; then the overall median for year-round workers if the age bracket is unavailable; then the median for the parent’s known occupation in the local area; and finally minimum wage.⁴

Absent evidence otherwise, the court presumes a parent earns at least two-thirds of the statewide average wage. Exceptions apply to full-time students, parents with a physical or mental disability, and parents receiving public assistance such as TANF or SSI. A parent currently enrolled full-time in high school can be imputed at only 20 hours per week at minimum wage.²

Deviations From the Standard Amount

The table produces a presumptive figure, not a rigid one. Under RCW 26.19.075, a judge can deviate upward or downward when the standard number would be unjust, but the reasons have to be in written findings.⁵ Recognized grounds include:

A residential schedule where the child spends significant time with the paying parent. The general threshold is around 73 overnights per year, or roughly 20 percent. This deviation cannot leave the receiving household short of the child’s basic needs and is not available if the child receives TANF.
Involuntary extraordinary debt, major differences in living costs between the two households, or a child’s special medical or educational needs.
Nonrecurring income such as overtime, bonuses, or contract pay that does not repeat year to year. The court reviews two calendar years before deciding.
The income of a new spouse or partner, which alone is not grounds for deviation but can be considered along with other factors.
Support obligations to, or income from, children in other relationships.

Health Insurance, Medical Costs, and Daycare

The child support worksheet asks each parent to report the cost of the child’s health insurance premium. That cost is generally added to the basic support obligation and split proportionally by income share. When the paying parent carries the insurance, they typically receive a credit against their support obligation for the premium cost.

Uninsured medical, dental, and vision costs are shared in the same proportion.⁶ Keep receipts for co-pays, prescriptions, orthodontics, and similar expenses; they are billed on top of the base support amount. Work-related daycare is handled the same way.

The Paperwork You Need to File

Both parents must complete the Washington State Child Support Worksheet under penalty of perjury. It captures income, deductions, health insurance costs, and daycare, and it has to be filed in every proceeding where support is set.² A separate Financial Declaration lists monthly living expenses, assets, and debts.⁷

Each parent also has to supply supporting documentation: income tax returns for the previous two years, pay stubs covering the last six months, financial statements, and a work history.⁴ Self-employed parents need profit and loss statements that justify their reported figures. Parents who show up without documents often end up with income imputed at a level higher than what they actually earn.

How to Get a Support Order

Washington offers two routes: Superior Court or the Division of Child Support’s administrative process.

Filing in Superior Court

A Superior Court petition is the usual path when child support is part of a divorce, legal separation, or parentage action. The base civil filing fee is $200, but surcharges push the real cost higher. A parentage or custody filing usually runs around $310; a dissolution that includes child support runs closer to $364.⁸ Fee waivers exist for parents who cannot afford the cost.

After filing, the other parent has to be formally served. A process server, sheriff, or other authorized third party delivers the papers. Once served inside Washington, the other parent has 20 days to respond. Service outside the state allows 60 days, and service by publication also allows 60 days. When both parents agree on the terms, a judge can sign the order relatively quickly. When they don’t, the court can issue a temporary order while the case moves toward a settlement conference or trial.

The Administrative Route

The Division of Child Support can set an order without going through Superior Court by issuing a Notice and Finding of Financial Responsibility. This path is common when no court case for custody or parentage already exists. A parent who disagrees with the proposed amount can request an administrative hearing or schedule a court hearing within 20 days of receiving the notice.⁹ Administrative orders carry the same legal weight as court orders.

Changing an Order Later

Incomes change, children’s needs shift, and support orders need to keep up. Washington offers two ways to update one.

At any time, either parent can petition for modification by proving a substantial change in circumstances that was not anticipated when the original order was entered. Job loss, a large income change, a child developing new medical needs, or a significant change in the parenting schedule all qualify. The parent asking for the change carries the burden of proof.¹⁰

Once an order has been in place for at least 24 months, either parent can file a motion to adjust the amount based on changed income alone, without proving a substantial change in circumstances. This uses the current worksheets and the updated economic table to recalculate the obligation and is generally faster than a full modification.¹⁰ Courts can also build automatic periodic adjustments into the original order.¹¹

When Support Ends

Basic child support in Washington generally ends when the child turns 18 or graduates from high school, whichever comes later. A child still finishing high school after 18 keeps receiving support until graduation but no later than their 19th birthday, whether they have graduated by then or not. Support can end sooner if the child is legally emancipated, gets married, or joins the military.

Adult children with disabilities are the exception. When a physical or mental condition prevents a child from becoming self-sufficient, a parent can ask that support continue past 18. The court weighs the severity of the condition, the child’s living situation, and each parent’s ability to pay. These cases are decided individually, usually through a modification of the existing order.

Post-Secondary Educational Support

Washington allows courts to order parents to contribute to college or vocational costs, but this is a separate order from basic child support and is not automatic. Before ordering post-secondary support, the court weighs the child’s age, abilities, and academic standing; what the parents expected for the child’s education while they were together; each parent’s education level, standard of living, and financial resources; the type of program the child is pursuing; and what the child would have received if the family had stayed intact.

The child must be enrolled in an accredited program, actively pursuing coursework, and maintaining good academic standing as the school defines it, and must keep both parents informed of enrollment. The court considers what the child contributes through work, grants, scholarships, and loans when setting the amount.¹²

Payments go directly to the school where feasible; otherwise the court directs payment to the child rather than to the custodial parent. Post-secondary support generally cannot extend past the child’s 23rd birthday, with narrow exceptions for children with disabilities.¹²

1
Washington State Legislature. RCW 26.19.020 – Child Support Economic Table
2
Washington Courts. Washington State Child Support Schedule
3
Washington State Legislature. RCW 26.19.065 – Standards for Establishing Lower and Upper Limits on Child Support Amounts
4
Washington State Legislature. RCW 26.19.071 – Standards for Determination of Income
5
Washington State Legislature. RCW 26.19.075 – Reasons for Deviation from the Standard Calculation
6
Washington State Legislature. WAC 388-14A-3312
7
Washington Courts. Financial Declaration – FL All Family 131
8
Washington State Legislature. RCW 36.18.020
9
Washington State Department of Social and Health Services. Child Support Modification
10
Washington State Legislature. RCW 26.09.170 – Modification of Decree for Maintenance or Support
11
Washington State Legislature. RCW 26.09.100
12
Washington State Legislature. RCW 26.19.090 – Standards for Postsecondary Educational Support Awards