How Long Does It Take to Do a Paternity Test?

A paternity test usually takes about one to two weeks from start to finish. The lab work itself runs three to five business days after your samples arrive,¹ and the rest of the time covers scheduling, collection, and shipping. How long a paternity test takes in your specific situation depends on whether you need results for personal knowledge or for court, whether the pregnancy is ongoing, and whether the alleged father is available to be tested.

The Lab Window Is Three to Five Business Days

Once samples reach the lab, technicians extract the DNA, amplify short tandem repeats (STRs), and compare the child’s markers against the alleged father’s. Standard processing takes three to five business days.¹ That window is the same whether the test is at-home or legal. Everything else that stretches the timeline happens outside the lab: getting a kit, scheduling appointments, mailing samples, and completing paperwork.

At-Home Kit: One to Two Weeks Total

An at-home paternity kit is the fastest route to an answer. You order the kit online or buy it at a pharmacy, collect cheek swabs from the child and alleged father, and mail the samples back. Cleveland Clinic estimates one to two weeks for results from the time samples arrive at the lab.² Add a few days on the front end for the kit to reach you and a few more for return shipping.

Ship early in the week when you can. Samples sitting in a mail facility over a weekend or holiday add dead time that has nothing to do with the lab. The tradeoff with at-home testing is that no one verified who provided the samples, so a court will not accept the results for child support, custody, or inheritance purposes.

Legal (Chain-of-Custody) Test: Add Scheduling Time

A legal paternity test requires an appointment at a certified collection facility. A trained technician verifies each participant’s identity with a government-issued photo ID, photographs the participants, completes chain-of-custody paperwork, and personally collects the samples. Those samples are sealed, labeled, and tracked from the collection site to the lab. Processing at the lab still takes three to five business days, but coordinating the appointment across all participants and completing the documentation add days or weeks to the overall timeline.¹

If the result needs to hold up in court or with a federal agency, confirm the lab is accredited by AABB before you book. USCIS will only accept DNA results from AABB-accredited labs for immigration and visa applications,³ and federal law requires states to admit genetic test results into evidence in paternity cases when the testing was performed by a lab approved by an accreditation body designated by the Secretary of Health and Human Services.⁴

Rush Processing for Faster Results

If you need an answer quickly, many labs offer rush processing for an additional fee. Some provide same-day or next-business-day turnaround.² Rush fees vary by lab and speed, so ask about pricing when you schedule. Rush processing only compresses the lab window; it does not remove shipping time or the wait for a legal collection appointment.

Prenatal Paternity Testing Timelines

You do not have to wait until a baby is born. A non-invasive prenatal paternity test (NIPP) can be performed as early as the seventh or eighth week of pregnancy.² The lab draws the mother’s blood, isolates fetal DNA circulating in her bloodstream, and compares that fetal DNA profile to a cheek swab from the alleged father. Results come back in about one week once testing begins.⁵

Two older prenatal methods still exist but are rarely used solely for paternity because they carry medical risk. Chorionic villus sampling (CVS) collects placental tissue between 10 and 13 weeks, and amniocentesis draws amniotic fluid between 15 and 20 weeks. Both are invasive, and results can take several weeks.²

Court-Ordered Testing Runs on Court Time

When paternity is disputed in a child support, custody, or inheritance case, either party can ask the court to order genetic testing. Federal law requires every state to have procedures for ordering DNA tests in contested paternity cases when a party files a sworn statement supporting the request.⁴

The court process adds substantial time beyond the lab work. You file a petition, wait for a hearing date, get the court order, schedule the collection appointment, and then wait for results. Uncontested cases where the alleged father cooperates often resolve within one to three months. Contested cases with multiple hearings or disputes over custody and support can stretch to six months or longer. Court backlogs and scheduling delays in your jurisdiction are the biggest wild cards.

Refusing a court-ordered test carries real consequences. A judge can hold a non-compliant party in contempt of court, which brings potential fines and even jail time. Courts may also draw an adverse inference from the refusal and use that against the refusing party in custody, visitation, and support decisions.

When the Alleged Father Cannot Be Tested Directly

If the alleged father has died, is missing, or refuses to participate voluntarily and no court order is in place, DNA testing can still establish a biological relationship through other family members. These tests take the same amount of lab time as a direct paternity test, but the planning is different because you have to identify and coordinate additional participants.

Grandparentage testing compares the child’s DNA to one or both of the alleged father’s parents. It is the most common alternative when the father is unavailable.
Sibling or aunt/uncle testing checks whether the child shares enough DNA with the alleged father’s siblings or other known children to confirm a biological connection.
Y-chromosome (Y-STR) testing compares Y-chromosome markers passed down through the male line. A match between the child and the alleged father’s brother, father, or grandfather confirms shared paternal lineage.

Indirect tests are less statistically powerful than a direct father-child comparison. Including the mother’s sample often strengthens the analysis, which can mean an extra collection step to schedule.

What Can Stretch Your Timeline

The three-to-five-day lab window assumes everything goes smoothly. Several things can push it out.

Shipping delays. Mailing samples over a weekend or holiday adds dead time. Ship early in the week.
Poor sample quality. A contaminated or degraded sample means the lab has to request a recollection, which restarts the clock. It is the most common cause of significant delays and is almost always preventable by following the collection instructions.
Incomplete paperwork. Legal tests require identity verification forms, consent documents, and chain-of-custody records. Missing or incorrect paperwork holds everything up until it is resolved.
Inconclusive results. In rare cases, the lab cannot reach a definitive conclusion. This happens more often in sibling or grandparent tests than in direct father-child tests. Adding the mother’s sample often resolves the ambiguity, but that means another round of collection and processing.

Cheek swab kits also come with pre-collection instructions. Before swabbing, avoid eating, drinking, brushing your teeth, using mouthwash, smoking, or chewing gum. Cleveland Clinic recommends waiting at least an hour beforehand; some kit manufacturers specify 30 minutes.² Following the longer window costs nothing and helps you avoid a recollection.

Quick-Reference Timeline

At-home kit, order to results: about one to two weeks, including shipping both ways and lab processing.²
Legal test, appointment to results: about one to two weeks after collection, depending on scheduling and the lab.¹
Rush processing: same-day or next-day results available at many labs for an additional fee.²
Non-invasive prenatal test: available as early as seven to eight weeks of pregnancy, with results in about one week.⁵
Court-ordered test, filing to results: one to three months in uncontested cases, potentially six months or more when disputed.

1
Labcorp DNA. How DNA Testing Works
2
Cleveland Clinic. DNA Paternity Test
3
AABB. Become AABB-Accredited: Relationship (DNA) Testing
4
Office of the Law Revision Counsel. 42 USC 666 – Requirement of Statutorily Prescribed Procedures to Improve Effectiveness of Child Support Enforcement
5
American Pregnancy Association. Non-Invasive Prenatal Paternity Test