To get a DNA paternity test, decide first whether you need the result for your own peace of mind or for a court. An at-home kit costs roughly $30 to $200, ships to your door, and uses a simple cheek swab. A legal test at an accredited collection site costs $300 to $500, documents every sample from collection to lab, and is the only version a court will accept for child support, custody, inheritance, or a birth certificate change. Either way, results typically come back within three to five business days.1Labcorp. How DNA Testing Works
The lab analysis is the same in both cases. What differs is who watched the samples get collected.
Ordering an At-Home Test
At-home kits are sold online and at many pharmacies. Once the kit arrives, you swab the inside of the cheek for each person being tested, seal the swabs in their individually labeled envelopes, and mail everything back to the lab. Follow the prep instructions carefully: no eating, drinking, smoking, or chewing gum for at least an hour before swabbing, and never let one person’s swab touch another’s envelope.
Pricing varies because some kits bundle the lab processing fee and some charge it separately when you return the samples. Read the fine print before you buy so you know the full cost.
The accuracy is identical to a legal test because the same laboratory runs the same analysis on the same type of sample. What you lose is proof of who actually provided the swabs. Nobody verified identities, nobody photographed the participants, and nobody maintained a documented chain of custody. That means at-home results cannot be used in any court proceeding, whether for child support, custody, visitation, inheritance, or amending a birth certificate.2Labcorp. Specimen FAQ If there’s any chance you’ll need the result in court later, pay for the legal test the first time.
Getting a Legal Test
A legal paternity test produces a report that holds up in court. The difference from an at-home test is procedural: trained collectors verify identities, photograph each participant, and seal and label every sample in front of you, creating a chain of custody that forecloses later claims of tampering or sample-swapping.
Start by finding an accredited laboratory. Many states require the lab to be accredited by the AABB, formerly the American Association of Blood Banks, which is the primary accrediting body for relationship testing in the United States.3AABB. Become AABB-Accredited – Relationship (DNA) Testing Federal agencies also require AABB accreditation for immigration-related DNA tests. The AABB maintains an online directory of accredited facilities you can search by location.4AABB. DNA Relationship Testing FAQs
Call the lab to schedule appointments at an approved collection site, which is usually a clinic, lab office, or other neutral location. Everyone being tested needs to bring photo ID. At the appointment, the collector checks identification, photographs each participant, and takes cheek swabs. Results arrive within the same three-to-five business day window as at-home tests, and many labs offer expedited processing for an added fee.
Testing Before the Baby Is Born
You don’t have to wait until birth. A non-invasive prenatal paternity test analyzes fragments of fetal DNA circulating in the pregnant mother’s blood and compares them to a cheek swab from the alleged father. The test can be performed as early as the seventh or eighth week of pregnancy.5Cleveland Clinic. DNA Paternity Test: Procedure, Accuracy and Results
The process requires a standard blood draw from the mother and a cheek swab from the alleged father. Accuracy is comparable to postnatal testing at 99.9% for inclusions. The price is higher, often $1,000 to $2,000, because analyzing fetal DNA in maternal blood is more complex than reading a straightforward cheek sample. Both informational and legal versions exist, but not every lab offers a prenatal test with chain-of-custody documentation. If you need a court-admissible result, confirm that before booking.
Who Needs to Provide a Sample
At minimum, the alleged father and the child both provide samples. Including the mother’s DNA is optional but strengthens the result, especially when the genetic markers are ambiguous or when the alleged father could be closely related to the true biological father, such as a brother. Without the mother’s sample, the test still works and remains highly accurate; the lab simply has to infer which half of the child’s DNA came from her rather than confirming it directly.6PubMed Central. How Many Familial Relationship Testing Results Could Be Wrong
Consent rules matter when a minor is involved. A legal paternity test on a child generally requires consent from a parent or legal guardian. When both parents are participating, that is straightforward. When one parent wants to test the child without the other’s knowledge, the rules vary by state: some allow a custodial parent to consent alone, others require consent from both parents or a court order. At-home kits are less regulated, but the lab’s terms of service still typically require that whoever orders the kit has legal authority over the child being tested.
If the alleged father is deceased or otherwise unavailable, courts can order testing of his parents, siblings, or other children to reconstruct his genetic profile. The person requesting this kind of alternative testing generally has to show good cause, and the court weighs the fairness to the relatives being asked to participate.
When a Court Orders the Test
If someone has filed a paternity action and the alleged father won’t participate voluntarily, a court can order genetic testing. Family courts routinely issue these orders in child support and custody cases, and the state child support enforcement agency can also initiate testing when it is pursuing support on behalf of a custodial parent.
Refusing a court-ordered test carries real consequences. The most common outcome is an adverse inference: the court presumes you are the father and proceeds accordingly, which usually produces a child support order. In some jurisdictions, refusal can also be treated as contempt of court, with possible fines or jail time. Ignoring the order doesn’t make the case disappear. It means the court decides without your input, and that decision almost always goes against you.
Reading the Results
A paternity test report centers on two numbers.
The Combined Paternity Index (CPI) is a ratio showing how many times more likely the genetic results are if the tested man is the biological father than if he is not. A CPI of 500 means the evidence is 500 times more consistent with paternity than with a random unrelated man. A CPI of zero means the tested man is excluded.
The Probability of Paternity converts the CPI into a percentage. The widely adopted legal standard treats a probability of 99% or higher, with a CPI of at least 100 to 1, as identification of the biological father. Most positive results clear this bar easily, often reading 99.99% or higher. A probability of 0% means exclusion.
The strength of a result depends partly on whether the mother’s DNA was included and on how many genetic markers the lab tested. Current-generation kits analyzing 21 or more markers produce more reliable results than older kits that read only 15.6PubMed Central. How Many Familial Relationship Testing Results Could Be Wrong If a result looks inconclusive or the CPI is lower than you expected, ask whether retesting with a broader panel, or adding the mother’s sample, can resolve the ambiguity.
What a Legal Result Lets You Do
Once paternity is legally established, several rights and obligations follow:
- Either parent can seek a child support order. Courts calculate the amount based on each parent’s income and the child’s needs, and the obligation typically runs until the child turns 18 or 19 depending on the state.
- An established father can seek a parenting plan, including custody or visitation. Without a legal determination of paternity, most courts will not grant these rights.
- The father’s name can be added to the child’s birth certificate by filing with the state vital records office, usually for an administrative fee of $15 to $25.
- The child gains inheritance rights, including the right to inherit if the father dies without a will.
- The child may become eligible for the father’s health insurance, Social Security benefits, veterans’ benefits, and life insurance proceeds.
If the test excludes you and you had previously signed a voluntary acknowledgment of paternity or appeared on the birth certificate as the father, the DNA result alone does not undo any of that. You have to file a motion with the court to set aside the paternity finding, and both the grounds and the deadlines vary significantly by state. Many states impose strict time limits, so act quickly.