To get a court-ordered DNA test for paternity, you file a petition in family court along with a sworn statement showing a reasonable possibility of biological parentage. Under the Uniform Parentage Act, which most states have adopted in some form, the judge is generally required to order testing once that threshold is met.1Uniform Law Commission. Uniform Parentage Act 2017 Final Act The full process, from filing to receiving results, usually takes two to four months.
Who Has the Right to File
You need legal standing, meaning a direct stake in the outcome. Under the Uniform Parentage Act, any party to the case can request genetic testing by submitting a sworn statement that either alleges a reasonable possibility that someone is the child’s genetic parent or denies genetic parentage and states facts supporting that denial.1Uniform Law Commission. Uniform Parentage Act 2017 Final Act
In practice, the people who file are usually a mother trying to establish the father’s identity for support or custody purposes, an alleged father who wants to confirm or rule out a biological link, or a presumed father (typically a husband) who believes he is not the child’s biological parent. A state child support agency can also file, but only when there is no presumed, acknowledged, or already-adjudicated parent other than the birth mother.1Uniform Law Commission. Uniform Parentage Act 2017 Final Act The child, through a legal representative, can occasionally file as well, though this is uncommon and typically arises in inheritance disputes.
Filing the Petition
The petition goes in your local family court, which some jurisdictions call a juvenile or domestic relations court. You are asking the court to order genetic testing, and the paperwork needs to include a sworn statement explaining why testing is warranted, the names of the parties, the child’s name and date of birth, and the nature of the relationship you are trying to establish or disprove.
You do not have to prove paternity at this stage. The standard is a “reasonable possibility” of biological parentage. That might rest on a relationship during the likely conception period, an informal acknowledgment of fatherhood, or an existing demand for support. Supporting documents like a birth certificate, a prior acknowledgment-of-paternity form, or an existing custody order strengthen the petition, though they are not always required.
Filing fees vary widely. Some states waive them entirely for paternity cases; other counties charge over $400 for related civil filings. If you cannot afford the fee, nearly every court has a fee-waiver application based on household income. Ask the clerk when you file.
An attorney is not strictly required, and many people file on their own. But mistakes in the paperwork, like failing to name the right parties or omitting the sworn statement, can delay the case or get the petition dismissed. If the other side is likely to fight the request, legal help is worth the cost.
Serving the Other Party
After filing, copies of the petition and a court summons must be formally delivered to every other party. This is service of process, and it cannot be done casually. You cannot hand the papers over yourself. Service has to be carried out by someone at least 18 years old who is not a party to the case, whether a county sheriff, a private process server, or another adult you designate.
The server completes a proof-of-service form documenting who was served, when, where, and how, and that form is filed with the court. Without valid proof of service, any hearing held can be challenged or thrown out. If the other party is actively avoiding service, most jurisdictions allow alternative methods like posting notice at a last known address or publishing in a local newspaper, but you need the court’s permission first. Process server fees typically run between $20 and $100 for standard service, with higher costs when the server has to make multiple attempts.
The Hearing and the Standard the Judge Applies
Once service is complete and the response period has passed, the court schedules a hearing. If nobody objects, the hearing is brief: you present the petition, the judge confirms the sworn statement meets the reasonable-possibility standard, and the order issues.
When the other side contests, the hearing gets more involved. The respondent might argue there is no factual basis for testing, that the request is harassment, or that testing would not serve the child’s best interests. Both sides can present evidence, call witnesses, and make arguments. The petitioner’s burden stays relatively low. You are not proving paternity, only proving there is enough reason to find out. Evidence like cohabitation during the likely conception period, the alleged father’s own statements about the child, or financial support already provided will generally clear the bar.
When a Judge Can Deny the Request
Judges do not rubber-stamp every DNA request. Several legal doctrines give courts reason to refuse, especially when an established parent-child relationship is at stake.
The Marital Presumption
If a child is born during a marriage, the law presumes the husband is the father. Every state recognizes this presumption, though the rules for overcoming it vary. Under the Uniform Parentage Act, a presumed father can challenge paternity by showing that he and the mother neither lived together nor had a sexual relationship during the likely conception period, and that he never held the child out as his own.1Uniform Law Commission. Uniform Parentage Act 2017 Final Act Some states impose short time limits, sometimes as brief as two years after the child’s birth. A man outside the marriage who believes he is the biological father faces an even steeper climb, and in some jurisdictions a biological connection alone will not overcome the presumption when the husband has been actively parenting.
Best Interests of the Child
When a child has a stable, long-standing relationship with a presumed parent, courts may refuse testing. Judges look at how long the presumed father has been parenting, the child’s emotional attachment, the potential harm of disrupting the relationship, and whether the child has relied on that parent’s role. A petition filed shortly after birth reads very differently than one filed on a teenager who has known one father for sixteen years.
Equitable Estoppel
Even without a marital presumption, a court can block testing when someone has held themselves out as the child’s parent for years. The theory is that it would be unfair to let an adult build a parent-child bond and then use DNA to walk away from it. What matters most is whether the child relied on that relationship, not whether the adult did.
Res Judicata
If paternity was already decided in a prior court proceeding, the doctrine of res judicata may prevent relitigating the question. A judge will not typically order a DNA test to challenge a paternity finding already made unless there is evidence of fraud or a material mistake of fact.
Why an Over-the-Counter DNA Kit Will Not Work
A home DNA test bought online or at a pharmacy has no legal weight. Courts reject those results because the participants collect the samples themselves, so there is no independent verification of who actually provided the DNA. Nobody checks identification, nobody witnesses the collection, and nobody confirms the samples were not tampered with in transit.
A court-admissible test requires chain of custody: an unbroken, documented trail from sample collection to lab analysis. A trained, unrelated collector verifies each participant’s identity with government-issued photo ID, personally witnesses the cheek swab, seals the samples in tamper-evident packaging, and ships them to the lab using a trackable method. Any break in that chain can get the results thrown out. If a home test already has you worried, treat it as motivation to file for a court-ordered test, not as evidence to bring to a judge.
How the Testing Is Done
Once the judge signs the order, it specifies which accredited laboratory will perform the analysis, who needs to be tested, and the deadline. Many state laws require accreditation from the Association for the Advancement of Blood and Biotherapies (AABB, formerly the American Association of Blood Banks), which has been the benchmark for relationship testing quality since 1982.2Association for the Advancement of Blood & Biotherapies. DNA Relationship Testing FAQs Federal immigration cases require AABB accreditation, and most state court systems recognize only AABB-accredited labs for legal proceedings.3Association for the Advancement of Blood & Biotherapies. Become AABB-Accredited – Relationship DNA Testing
The test itself is painless. Each participant goes to the collection site, shows photo identification, and has the inside of a cheek swabbed with a soft brush or cotton applicator. The collector documents everything, seals the samples, and sends them to the lab. Results usually come back within two to five weeks.
Legal DNA tests generally cost between $300 and $500, covering professional collection and laboratory analysis. The order specifies who pays. Under the Uniform Parentage Act, the requesting party pays upfront, though the parties can agree to split the cost or the court can allocate it differently.1Uniform Law Commission. Uniform Parentage Act 2017 Final Act When a child support agency initiates the case, the agency typically covers the initial cost.
If a specimen is not available from the alleged parent, as in a case where that person has died, the court can order testing of close relatives including the alleged parent’s own parents, siblings, or other children.1Uniform Law Commission. Uniform Parentage Act 2017 Final Act The court has to find that the need for testing outweighs the tested relative’s privacy interests.
If the Other Person Refuses
A court order is not optional. Under the Uniform Parentage Act, a genetic-testing order is enforceable by contempt.1Uniform Law Commission. Uniform Parentage Act 2017 Final Act A person who refuses can face fines, sanctions, or jail time until they comply.
Refusal also carries an evidentiary consequence. The judge can draw an adverse inference, essentially concluding the person refused because the results would have confirmed the other side’s claim. In many cases, the court will simply rule on paternity from the remaining evidence and treat refusal as supporting the opposing party. Stonewalling almost always backfires.
Reading the Results
DNA test results in paternity cases are reported as a probability of parentage. Under the Uniform Parentage Act, a person is identified as a genetic parent if testing shows at least a 99 percent probability of parentage (using a prior probability of 0.50) and a combined relationship index of at least 100 to 1.1Uniform Law Commission. Uniform Parentage Act 2017 Final Act In practice, modern testing frequently returns probabilities of 99.99 percent or higher.
Once results cross the 99 percent threshold, they create a rebuttable presumption of parentage. The identified parent can still contest, but the burden shifts heavily and would require additional testing at their own expense along with a legitimate basis for doubting the initial results. When the first test excluded someone as a genetic parent, that exclusion is generally treated as definitive.
Any party who contests the results can request a second round of testing. The court or child support agency must order additional testing on request, but if the first test already identified a genetic parent, the person challenging the results has to pay upfront.1Uniform Law Commission. Uniform Parentage Act 2017 Final Act Procedural errors during collection, like a broken chain of custody or missing identification documentation, can also support a challenge to admissibility, though those attacks target the process rather than the science.
Deadlines for Filing
Every state sets a deadline for filing a paternity action, and missing it means losing the right to request testing. In most states, the deadline runs until the child turns 18. A handful extend the window to age 21 or 23, while a few set much shorter limits of two to four years from the child’s birth or from a specific event like a paternity acknowledgment. A small number of states impose no statute of limitations on paternity establishment at all.
Exceptions to the deadline exist in many jurisdictions for fraud, material mistake of fact, or situations where the respondent successfully avoided service. The time limit can also differ depending on whether someone is already a presumed father versus a situation where fatherhood was never formally established. A court will dismiss an otherwise valid petition if the statute of limitations has expired, and no amount of compelling evidence about the biological relationship will overcome that procedural bar. If the child in your case is older, or if you are trying to unwind an existing paternity judgment rather than establish one for the first time, checking your state’s specific deadline is the first thing to do.