Court-Ordered Paternity Test in Washington State: Process and Costs

To get a court-ordered paternity test in Washington state, you file a Petition to Decide Parentage in the superior court of the county where the child lives, then file a separate Motion for Genetic Testing asking the judge to order DNA testing of the child and the alleged parent. Washington calls this a “parentage” action rather than a paternity action, but the mechanics for compelling a DNA test are the same. The process runs under Washington’s Uniform Parentage Act at RCW 26.26A, using mandatory forms from the Washington State Courts.¹

When a Court Order Is Actually Necessary

Not every situation needs a judge. Washington offers a Voluntary Acknowledgment of Parentage, signed by both parents at the hospital, a local health department, or a Division of Child Support office. Once final, it carries the same legal weight as a court order.²

A court order becomes necessary when that voluntary path is unavailable. The Washington State Department of Health identifies the common triggers: there are questions about who a parent is, the parties disagree and will not sign the acknowledgment, or someone wants to add or remove a parent on the birth certificate.³ Typical examples include a birth parent who believes more than one man could be the father, an alleged father who disputes the claim, or a potential parent who has died or is otherwise unable to sign.

Who Can File

Under RCW 26.26A.405, the following people have standing to open a parentage case in Washington:

The child, through a legal representative if a minor
The woman who gave birth
Any person who is or claims to be a parent
A state child support agency
An authorized representative acting for someone deceased, incapacitated, or a minor
An intended parent in a surrogacy arrangement⁴

The state agency route matters if money is tight. When a child receives public assistance, Washington’s Division of Child Support can start a parentage action on its own and pays for the genetic testing upfront.

Filing the Petition

You cannot draft a parentage petition from scratch in Washington. The court requires standardized forms. To start a case, you need:

FL Parentage 301, Petition to Decide Parentage
FL Parentage 300, Summons: Notice About Parentage
FL All Family 001, a confidential information form that stays sealed⁵

The Petition asks for identifying information about each party and the child, the basis for your claim, and the orders you want from the court. File it with the superior court in the county where the child lives.⁶

Filing Fees and Fee Waivers

Expect a filing fee of roughly $300 or more. King County charges $310 for a Uniform Parentage Act filing, and other counties are in the same range. If you cannot afford it, you can request a waiver under General Rule 34. You qualify if you receive public benefits like TANF, SSI, or food stamps, or if your household income sits at or below 125 percent of the federal poverty guidelines.

Serving the Other Party

After filing, the Summons and Petition must be personally delivered to the other party. You cannot do it yourself. The person doing the serving must be at least 18 and not a party to the case. That can be a friend, a professional process server, or the county sheriff. When personal service is not possible after genuine effort, you can ask the court to allow service by certified mail or, as a last resort, by publication in a newspaper. Once served, file proof of service on form FL All Family 101.⁵

Asking the Judge to Order the DNA Test

Filing the petition alone does not trigger a DNA test. You need a separate Motion for Genetic Testing, form FL Parentage 308. The other party responds on FL Parentage 309, and the court rules on FL Parentage 310. When both sides agree, they can skip the fight and file an Agreed Order for Genetic Testing on FL Parentage 311.⁵

Federal law backs the request. Under 42 U.S.C. § 666, states must have procedures requiring the child and all parties in a contested paternity case to submit to genetic testing when any party requests it, so long as the request is supported by a sworn statement. The moving party either alleges parentage with facts showing a reasonable possibility of sexual contact, or denies parentage with facts suggesting contact did not occur.⁷

How the Testing Works

Court-ordered genetic testing in Washington uses a cheek swab. A trained technician collects samples from the child and the alleged parent under controlled conditions and completes a chain of custody declaration on form FL Parentage 312 to document that the samples were handled properly. The samples then go to an accredited laboratory. Results usually come back within a few weeks, in the form of a report showing a probability of parentage and a combined relationship index.

Who Pays

Legal-grade DNA paternity tests generally run between $200 and $500. When a state child support agency orders the test, the agency covers the cost upfront, and Washington can recover that cost from the father if parentage is established.⁷ In a privately filed case, the court can allocate testing costs between the parties under RCW 26.26A.330.

What Happens If the Other Party Refuses

Refusing a court-ordered genetic test in Washington backfires quickly. A testing order under RCW 26.26A.310 is enforceable by contempt, which can carry fines or jail. The bigger risk is substantive: when an alleged parent will not submit to testing, the court can declare them the legal parent anyway, denial or no denial.⁸

The court can also order temporary child support from an alleged parent who is refusing testing while the case remains open.⁹ Refusing does not make the case go away. It makes the outcome worse.

What the Results Mean in Court

Washington sets a specific numeric threshold. A person is identified as a genetic parent when the test shows at least a 99 percent probability of parentage, using a prior probability of 0.50, together with a combined relationship index of at least 100 to 1.¹⁰ Modern DNA testing routinely exceeds that, often reaching probabilities above 99.9 percent.

Results meeting the threshold create a presumption of parentage. The other party can push back by showing a testing error or asking for additional testing. Results below 99 percent do not create a presumption, but the court can still consider them alongside other evidence.

Presumed Parents Change the Analysis

Before you file, check whether Washington already treats someone as a “presumed parent” of the child. That happens, among other ways, when the person was married or in a registered domestic partnership with the birth parent at the child’s birth, when the child was born within 300 days of the marriage or partnership ending, when the person married the birth parent afterward and asserted parentage, or when the person lived with the child for the first four years of the child’s life and openly treated the child as their own.¹¹ If a presumed parent exists, you are not just establishing parentage; you are asking the court to overcome that presumption, and genetic testing is usually how that gets done.

What the Court Orders After Parentage Is Decided

A parentage case does not end at the DNA result. The court issues a Final Parentage Order on form FL Parentage 316 and typically addresses child support, medical support, and a parenting plan in the same case.

Child support is calculated under Washington’s standardized schedule, which uses each parent’s income, the number of children, the residential schedule, and expenses like childcare or medical costs. A judge can deviate from the standard calculation, but the reasons must be written into the order.¹²

The court also addresses health insurance. Federal law requires employment-based group health plans to cover a parent-employee’s children when directed by a Qualified Medical Child Support Order, whether or not the parents were married.¹³

Finally, the court sets a parenting plan on form FL All Family 140, covering where the child lives, the time each parent has, and how major decisions about education, healthcare, and religion get made. The child’s best interest controls.⁵

Time Limits

Washington does not impose a strict deadline on filing an initial action to establish parentage of a child who has no presumed, acknowledged, or adjudicated parent. Deadlines do apply elsewhere. A signed Acknowledgment of Parentage can be rescinded within 60 days of its effective date or before the first court hearing involving the child, whichever comes first. After the rescission window closes, a signatory has four years to challenge the acknowledgment, and only on grounds of fraud, duress, or material mistake of fact.¹⁴

Where a parent is alleging that a child was conceived through sexual assault, the claim generally must be filed within four years of the child’s birth. Waiting rarely helps in any parentage matter, and can quietly close doors, so moving promptly is worth the effort.

1
Washington State Legislature. Washington Code RCW 26.26A – Uniform Parentage Act – Section: RCW 26.26A.070
2
Washington State Department of Social and Health Services. Establishing Parentage
3
Washington State Department of Health. Court Ordered Parentage
4
Washington State Legislature. Washington Code RCW 26.26A – Uniform Parentage Act – Section: RCW 26.26A.405
5
Washington State Courts. Court Forms: Petition to Decide Parentage
6
Washington State Legislature. Washington Code RCW 26.26A – Uniform Parentage Act – Section: RCW 26.26A.030
7
Office of the Law Revision Counsel. 42 US Code 666 – Requirement of Statutorily Prescribed Procedures to Improve Effectiveness of Child Support Enforcement
8
Washington State Legislature. Washington Code RCW 26.26A – Uniform Parentage Act – Section: RCW 26.26A.430
9
Washington State Legislature. Washington Code RCW 26.26A – Uniform Parentage Act – Section: RCW 26.26A.470
10
Washington State Legislature. Washington Code RCW 26.26A – Uniform Parentage Act – Section: RCW 26.26A.325
11
Washington State Legislature. Washington Code RCW 26.26A – Uniform Parentage Act – Section: RCW 26.26A.115
12
FindLaw. Washington Code RCW 26.19.075 – Standards for Determination of Child Support
13
U.S. Department of Labor. Qualified Medical Child Support Orders
14
Washington State Legislature. Washington Code RCW 26.26A – Uniform Parentage Act – Section: RCW 26.26A.235 and RCW 26.26A.240