Child support in Washington
Washington uses the income-shares model: both parents' incomes count, and each parent pays a share of the child's support. To open a case, contact the Division of Child Support (DCS), Washington State Department of Social and Health Services at 1-800-442-KIDS (5437).
Checked against official sources: Oct 25, 2026. · Free letters and checklist ↓
How much child support in Washington?
Both parents' monthly net incomes are combined and looked up in the state economic table to find the basic support for each child. Each parent's share is in proportion to their income. Health care, day care and special child-rearing costs are shared in the same proportion.
Law: RCW 26.19.011-26.19.080
We don't estimate Washington's amount here: its formula uses both parents' incomes and other facts, and a home-made number could mislead you. The official tool gives the real starting number:
Open a child support case in Washington
- Apply
- Apply online
- How to open a case
Print and send DCS forms 18-078 and 14-057 (plus 18-433 if you already have an order) by email, mail (DCS Central Services, P.O. Box 11520, Tacoma, WA 98411), fax (866-668-9518) or in person at a DCS office. You can also ask DCS to mail you forms or call 800-442-KIDS. Use one enrollment form for each noncustodial parent. If you get TANF, a case opens automatically. You can also ask for support in a court case (divorce or parentage).
- Yearly fee
$35 per case each federal fiscal year (Oct. 1-Sept. 30), kept from support after DCS has sent the custodian at least $550 that year, if the custodian has never received TANF, Tribal TANF or AFDC. The paying parent still gets full credit. You can ask DCS for a hardship exception.
Law: RCW 74.20.040
Source: DSHS form 18-686A
- Forms
- Paternity (legal fatherhood)
Unmarried parents can sign an Acknowledgment of Parentage, usually at the hospital or with a midwife; it is free to file if signed within 5 days of birth, and DCS pays the filing fee if you sign at a DCS office. Forms are also at the Department of Health, county health departments and DCS offices. Parentage can also be set by court order, with genetic testing if needed.
Washington child support by topic
How support is calculated in Washington
The model, the percentages or the official calculator, and low-income rules.
Change child support in Washington
When you can ask, how to ask, and a review letter.
Collect unpaid support in Washington
Collection tools, interest and license rules, and a letter.
When support ends in Washington
The end age, high school and disability rules.
How child support is figured in Washington
- Model
- Income shares
- How it works
Both parents' monthly net incomes are combined and looked up in the state economic table to find the basic support for each child. Each parent's share is in proportion to their income. Health care, day care and special child-rearing costs are shared in the same proportion.
- Low income
If a parent's net income is below 180% of the federal poverty guideline for one person, the presumptive minimum is $50 per child per month. Basic support cannot push the paying parent below a self-support reserve of 180% of the poverty level (except for the $50 minimum), and total support usually cannot exceed 45% of a parent's net income.
Law: RCW 26.19.065, effective Jan. 1, 2026
- Official calculator
- Official Washington child support calculator
- Health insurance and medical costs
Parents must provide health care coverage for the child. Coverage through a parent's job or union is considered reasonable if it costs no more than 25% of that parent's basic support obligation; otherwise a parent may pay cash medical support (share of premiums, capped at 25% of basic support, plus share of uninsured costs). Health care costs are split in proportion to income.
Law: (RCW 26.09.105; WSCSS)
Law: RCW 26.19.011-26.19.080
Change a child support order in Washington
- When a change is allowed
You can ask to change support at any time if circumstances have substantially changed (quitting a job or cutting hours on purpose is not enough by itself). After 1 year, you can ask without a substantial change if the order causes severe economic hardship or a child needs support past 18 to finish high school. After 24 months since the order or last change, you can ask for an adjustment based on changes in either parent's income or in the economic table. DCS can seek a change if the order is at least 15% above or below the standard calculation.
Law: RCW 26.09.170
- How to ask
If you have a DCS case, ask DCS to review your order (administrative orders through DCS; court orders through the county prosecutor's office). Or file in superior court: Petition to Modify Child Support (FL Modify 501) for a substantial change, or Motion to Adjust Child Support Order (FL Modify 521) for the 24-month adjustment.
Can I ask for a change? Check your situation
Collect unpaid child support in Washington
Arrears means support that is past due. The child support agency can use these tools to collect it:
- Collection tools
- Income withholding
- Driver's, professional and recreational license suspension
- Federal tax refund intercept
- Liens and orders to withhold and deliver (bank accounts, property)
- Passport denial
- Contempt of court
- License suspension
More than 6 months of child support payments behind, or not paying an agreed or ordered arrears plan by more than 6 months of payments.
Law: RCW 74.20A.020(18), 74.20A.320
- Contempt of court
If a parent does not follow a support order, the other parent (or the state) can file a contempt action in superior court. The court can order the parent to appear and show cause, and can issue a bench warrant if they don't come.
Law: RCW 26.18.050
- Interest on unpaid support
12% a year on judgments for unpaid child support under a court or administrative order. DCS does not add interest to its own case records; it collects interest only on unpaid support that has been made a Washington judgment.
Law: RCW 4.56.110(2)
Source: OCSS Intergovernmental Reference Guide, Washington profile
Law: RCW 74.20A.320, RCW 26.18.050, ch. 26.18 RCW, ch. 74.20A RCW
When child support ends in Washington
- Support ends
Set in the order; support ends when the child is emancipated, usually at 18, the age of majority. The court can extend support past 18 so a child can finish high school.
Law: RCW 26.28.010
- Exceptions
The court may order postsecondary (college or vocational) support for a dependent child, usually not past the 23rd birthday except for exceptional circumstances such as disability; the child must stay enrolled and in good standing and share grades with both parents.
Law: RCW 26.19.090
Law: RCW 26.09.170(3), (8)(b); 26.19.090; 26.28.010
When does support end? Check your situation
Free help in Washington
Official self-help
Free letters and checklist
Ask the agency to review (change) your order
A letter to the child support agency asking for a review and adjustment.
Ask the agency to collect unpaid support
A letter asking the agency to enforce the order and collect what is past due.
Checklist: what to bring to open a case
IDs, birth certificates, the other parent's details and your papers, with Washington's agency contact.
Good to know in Washington
- Since Jan. 1, 2026, the economic table covers combined net incomes up to $50,000 a month, and the self-support reserve rose to 180% of the federal poverty level. (RCW 26.19.020, 26.19.065; 2025 c 272)
- If you sign the Acknowledgment of Parentage within five days of your child's birth, there is no fee to file it. (DCS Establishing Parentage page)
- Support can be reduced to $10 a month per order while a paying parent is incarcerated for 6 months or more. (RCW 26.09.170(6))
Changes in 2024–2026
2025 c 272 (effective Jan. 1, 2026) replaced the economic table (now presumptive up to $50,000 combined monthly net income), raised the self-support reserve and the presumptive-minimum threshold to 180% of the federal poverty guideline, and kept the $50 per child minimum. A further amended version of RCW 26.09.170 takes effect April 1, 2027, adding abatement to $50 per child per month while a paying parent is in court-ordered behavioral health treatment. The state support schedule forms (WSCSS) were updated in 2026.
Federal rules in every state
- Applying. If you don't get TANF, Medicaid or foster care help, a state may charge an application fee of up to $25 to open a child support case. Law: 42 U.S.C. 654(6)(B)(i)
- Yearly fee. If you never got TANF and the agency collected at least $550 for you in a year, the state charges a $35 yearly fee. It can come out of your support, but never out of the first $550. Law: 42 U.S.C. 654(6)(B)(ii)
- Review every 3 years. If your case is with the child support agency, either parent can ask it to review the order every 3 years and adjust it to the guidelines. Law: 42 U.S.C. 666(a)(10)(A); 45 CFR 303.8
- Past-due support. Each unpaid payment becomes a judgment on the day it is due. It can't be lowered later, except back to the date the other parent got notice of a request to change the order. Law: 42 U.S.C. 666(a)(9)
- Tax refunds. The federal government can take a federal tax refund to pay past-due child support. Law: 42 U.S.C. 664
- Passports. A parent who owes more than $2,500 in past-due support can be refused a passport. Law: 42 U.S.C. 652(k)
- Pay withholding limit. For support, up to 50% of take-home pay can be withheld if the parent supports another spouse or child, or 60% if not. It is 55% or 65% when support is more than 12 weeks behind. Law: 15 U.S.C. 1673(b)
- How long support lasts. How long support lasts follows the law of the state that made the order, even if you move. Law: 28 U.S.C. 1738B(h)(2)
Questions about child support in Washington
How is child support calculated in Washington?
Both parents' monthly net incomes are combined and looked up in the state economic table to find the basic support for each child. Each parent's share is in proportion to their income. Health care, day care and special child-rearing costs are shared in the same proportion.
Is there an official child support calculator for Washington?
What if the paying parent has a low income in Washington?
If a parent's net income is below 180% of the federal poverty guideline for one person, the presumptive minimum is $50 per child per month. Basic support cannot push the paying parent below a self-support reserve of 180% of the poverty level (except for the $50 minimum), and total support usually cannot exceed 45% of a parent's net income.
How do I apply for child support in Washington?
Print and send DCS forms 18-078 and 14-057 (plus 18-433 if you already have an order) by email, mail (DCS Central Services, P.O. Box 11520, Tacoma, WA 98411), fax (866-668-9518) or in person at a DCS office. You can also ask DCS to mail you forms or call 800-442-KIDS. Use one enrollment form for each noncustodial parent. If you get TANF, a case opens automatically. You can also ask for support in a court case (divorce or parentage).
Is there a yearly fee for child support services in Washington?
$35 per case each federal fiscal year (Oct. 1-Sept. 30), kept from support after DCS has sent the custodian at least $550 that year, if the custodian has never received TANF, Tribal TANF or AFDC. The paying parent still gets full credit. You can ask DCS for a hardship exception.
When can child support be changed in Washington?
You can ask to change support at any time if circumstances have substantially changed (quitting a job or cutting hours on purpose is not enough by itself). After 1 year, you can ask without a substantial change if the order causes severe economic hardship or a child needs support past 18 to finish high school. After 24 months since the order or last change, you can ask for an adjustment based on changes in either parent's income or in the economic table. DCS can seek a change if the order is at least 15% above or below the standard calculation.
How do I ask to change child support in Washington?
If you have a DCS case, ask DCS to review your order (administrative orders through DCS; court orders through the county prosecutor's office). Or file in superior court: Petition to Modify Child Support (FL Modify 501) for a substantial change, or Motion to Adjust Child Support Order (FL Modify 521) for the 24-month adjustment.
What happens if child support is not paid in Washington?
Arrears means support that is past due. The child support agency can use these tools to collect it: Income withholding; Driver's, professional and recreational license suspension; Federal tax refund intercept; Liens and orders to withhold and deliver (bank accounts, property); Passport denial; Contempt of court.
Can a license be suspended for unpaid child support in Washington?
More than 6 months of child support payments behind, or not paying an agreed or ordered arrears plan by more than 6 months of payments.
Can a parent be held in contempt for not paying in Washington?
If a parent does not follow a support order, the other parent (or the state) can file a contempt action in superior court. The court can order the parent to appear and show cause, and can issue a bench warrant if they don't come.
Is there interest on unpaid child support in Washington?
12% a year on judgments for unpaid child support under a court or administrative order. DCS does not add interest to its own case records; it collects interest only on unpaid support that has been made a Washington judgment.
When does child support end in Washington?
Set in the order; support ends when the child is emancipated, usually at 18, the age of majority. The court can extend support past 18 so a child can finish high school.
Does child support continue while my child finishes high school in Washington?
The court can extend support past 18 so a child can finish high school.
Can child support continue past the usual age in Washington?
The court may order postsecondary (college or vocational) support for a dependent child, usually not past the 23rd birthday except for exceptional circumstances such as disability; the child must stay enrolled and in good standing and share grades with both parents.
How is paternity established in Washington?
Unmarried parents can sign an Acknowledgment of Parentage, usually at the hospital or with a midwife; it is free to file if signed within 5 days of birth, and DCS pays the filing fee if you sign at a DCS office. Forms are also at the Department of Health, county health departments and DCS offices. Parentage can also be set by court order, with genetic testing if needed.
Who pays for the child's health insurance in Washington?
Parents must provide health care coverage for the child. Coverage through a parent's job or union is considered reasonable if it costs no more than 25% of that parent's basic support obligation; otherwise a parent may pay cash medical support (share of premiums, capped at 25% of basic support, plus share of uninsured costs). Health care costs are split in proportion to income.
More help on our sister sites
Sources
- Chapter 26.19 RCW (Child Support Schedule)
- RCW 26.09.170 (modification)
- RCW 26.09.105 (medical support)
- RCW 4.56.110 (interest)
- RCW 74.20A.020 and 74.20A.320 (license suspension)
- WSCSS Schedule (effective Jan. 1, 2026)
- DSHS 18-686A Notice of Increased Annual Fee
- DCS: Enroll in Child Support Services
- DCS: Child Support Modification
- DCS: Establishing Parentage
- RCW 26.18.050 (contempt)
- RCW 26.28.010 (age of majority)
Last checked: Oct 25, 2026.
- State plan requirements: application fee, annual fee, safeguards, 42 U.S.C. 654
- Required state laws: arrears as judgments, review every 3 years, UIFSA, 42 U.S.C. 666
- Federal tax refund offset, 42 U.S.C. 664
- Passport denial for child support arrears, 42 U.S.C. 652(k)
- Garnishment limits for support orders, 15 U.S.C. 1673(b)
- Full faith and credit for child support orders, 28 U.S.C. 1738B
- Office of Child Support Enforcement (federal)