How to Establish Paternity in New Hampshire
Reviewed by DocDraft Legal Team · New Hampshire · Last updated 2026-09-12
In New Hampshire, establishing paternity means legally naming a child's parent so the child can receive support, custody and parenting time, health coverage, inheritance, and benefits. New Hampshire spreads its rules across three chapters: the Uniform Act on Paternity (RSA 168-A) governs the court action and its deadline, the parentage provisions (RSA 168-B) supply the presumptions, and the blood-test act (RSA 522) sets the genetic-testing standard. Unmarried parents who agree can sign a voluntary acknowledgment of paternity, often called an affidavit of paternity, through the Department of Health and Human Services. Three levers are load-bearing. A court paternity proceeding must be commenced within eighteen years of the child's date of birth (RSA 168-A:12). A person is presumed to be a parent when the child is born to that person's spouse during the marriage, or within 300 days after it ends for any reason, and that presumption can be rebutted only by clear and convincing evidence (RSA 168-B:2). And genetic testing showing a 97 percent or higher probability of paternity creates a presumption that the tested man is the father, which is itself rebuttable by clear and convincing evidence (RSA 522:4). Attorney review of your situation is available through DocDraft.
Find out where you stand in New Hampshire
Where are you in establishing paternity?
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Do I have to go to court to establish paternity in New Hampshire?
No, not when the parents agree. They can sign a voluntary acknowledgment of paternity through the Department of Health and Human Services, usually at the hospital. A proceeding under the Uniform Act on Paternity is needed only when parents disagree, and the court can then order genetic testing (RSA 168-A, RSA 522:4).
How long do I have to establish paternity in New Hampshire?
A court proceeding to establish paternity must be commenced within eighteen years of the child's date of birth (RSA 168-A:12). That single, birth-anchored deadline runs from the day the child is born rather than from the child reaching adulthood, so the practical window closes at age 18.
What is the marital presumption of paternity in New Hampshire?
A person is presumed to be a parent when the child is born to that person's spouse during the marriage, or within 300 days after the marriage ends for any reason (RSA 168-B:2). The presumption can be rebutted in an appropriate action only by clear and convincing evidence.
What genetic-testing result establishes paternity in New Hampshire?
Under RSA 522:4, if genetic tests show that the alleged father is not excluded and the probability of paternity is 97 percent or higher, he is presumed to be the father. That presumption is admitted into evidence and may then be rebutted by clear and convincing evidence.
New Hampshire paternity law at a glance
New Hampshire does not put its paternity rules in one place. The Uniform Act on Paternity (RSA 168-A) governs the court action and, in RSA 168-A:12, sets a deadline of eighteen years from the child's date of birth, so the clock runs from birth, not from adulthood. The parentage chapter (RSA 168-B:2) supplies the presumptions: a person is presumed a parent when the child is born to that person's spouse during the marriage or within 300 days after it ends, and that presumption falls only to clear and convincing evidence. The genetic standard is distinctive too: under the blood-test act (RSA 522:4), a 97 percent probability, rather than the 99 percent several states require, is enough to presume paternity. Unmarried parents who agree can sign a voluntary acknowledgment of paternity through the Department of Health and Human Services, subject to the federal 60-day window to rescind.
Establishing New Hampshire paternity under a birth-anchored deadline
Suppose a child is born in New Hampshire to unmarried parents who agree on the father. Both sign a voluntary acknowledgment of paternity through the Department of Health and Human Services at the hospital, which establishes the parent-child relationship without a court order. If one parent has doubts, they can rescind within the federal 60-day window unless a related proceeding starts first. Had the parents disputed parentage, either could bring a proceeding under the Uniform Act on Paternity, which must be commenced within eighteen years of birth (RSA 168-A:12). The court could order genetic testing, and a probability of 97 percent or higher would presume the alleged father to be the father (RSA 522:4), rebuttable by clear and convincing evidence. Had the child been born to a spouse during a marriage, that spouse would be presumed a parent under RSA 168-B:2. Attorney review is available through DocDraft.
Relevant Laws
RSA 168-A:12 (statute of limitations)
Provides that no proceeding under the Uniform Act on Paternity shall be maintained unless commenced within eighteen years of the date of birth of the child in question.
RSA 168-B:2 (parent-child relationship; presumptions)
Provides that a person is presumed to be the parent of a child born to that person's spouse during the marriage, or within 300 days after it ends for any reason, and that the presumption may be rebutted in an appropriate action only by clear and convincing evidence.
RSA 522:4 (effect of blood and genetic test results)
Provides that when genetic tests show the alleged father is not excluded and the probability of paternity is 97 percent or higher, he is presumed to be the father, a presumption that may be rebutted by clear and convincing evidence.
RSA 168-A:9 (venue for a paternity proceeding)
Provides that a proceeding under the Uniform Act on Paternity may be brought in the county where the alleged father is present or has property, or in the county where the mother resides.
New Hampshire Department of Health and Human Services, Child Support
The Department of Health and Human Services provides the voluntary acknowledgment of paternity and, through its child-support program, can help unmarried parents establish paternity and support.
42 U.S.C. 666(a)(5) and 45 CFR 303.5 (federal rescission window)
Federal law requires every state child-support program to offer an in-hospital voluntary acknowledgment of paternity with a 60-day window to rescind, after which the acknowledgment can be challenged only for fraud, duress, or material mistake of fact.
Regional Variances
New Hampshire paternity rules at a glance
Where the rules live
New Hampshire splits its paternity law across the Uniform Act on Paternity (RSA 168-A) for the court action, the parentage presumptions (RSA 168-B), and the blood-test act (RSA 522).
Voluntary path and form
Unmarried parents establish paternity by signing a voluntary acknowledgment of paternity, often called an affidavit of paternity, through the Department of Health and Human Services, usually at the hospital.
Marital presumption and standard
A person is presumed a parent when the child is born to that person's spouse during the marriage or within 300 days after it ends for any reason (RSA 168-B:2), rebuttable only by clear and convincing evidence.
Deadline to establish
A court proceeding must be commenced within eighteen years of the child's date of birth (RSA 168-A:12), a deadline measured from birth rather than from the child reaching adulthood.
Genetic-testing threshold
A probability of 97 percent or higher creates a presumption of paternity (RSA 522:4), a lower trigger than the 99 percent several states use.
Who administers it
The Department of Health and Human Services provides the acknowledgment and helps establish support; disputed parentage is heard by the court under the Uniform Act on Paternity, which can order genetic testing.
Suggested Compliance Checklist
Confirm whether a marital presumption applies
Before signing or filing anything days after startingDetermine whether the child was born to a spouse during the marriage or within 300 days after it ended, which triggers New Hampshire's parentage presumption (RSA 168-B:2). That presumption can be rebutted only by clear and convincing evidence.
Get genetic testing if parentage is uncertain
Before signing an acknowledgment days after startingIf there is doubt about biological parentage, obtain genetic testing first. Under RSA 522:4, a result showing the alleged father is not excluded and a probability of 97 percent or higher presumes him to be the father.
Sign the voluntary acknowledgment of paternity
At the hospital or a local office days after startingUnmarried parents who agree sign a voluntary acknowledgment of paternity through the Department of Health and Human Services, recorded with the registrar to establish the parent-child relationship. Attorney review of your matter is available through DocDraft.
Track the 60-day rescission window
Within 60 days of signing days after startingTo cancel a signed acknowledgment, rescind within the federally required 60-day window, unless a related court or administrative proceeding begins first, after which it can be challenged only for fraud, duress, or material mistake of fact.
File under the Uniform Act on Paternity if parents disagree
Any time before the deadline days after startingIf parents do not agree, bring a proceeding under RSA 168-A in the proper county (RSA 168-A:9). The court can order genetic testing and enter a support order under RSA 458-C.
Keep records and calendar the eighteen-year deadline
Ongoing days after startingSave copies of the acknowledgment, any genetic-test results, and court papers, and calendar the deadline: a paternity proceeding must be commenced within eighteen years of the child's date of birth (RSA 168-A:12).
| Task | Description | Document | Days after starting |
|---|---|---|---|
| Confirm whether a marital presumption applies | Determine whether the child was born to a spouse during the marriage or within 300 days after it ended, which triggers New Hampshire's parentage presumption (RSA 168-B:2). That presumption can be rebutted only by clear and convincing evidence. | - | Before signing or filing anything |
| Get genetic testing if parentage is uncertain | If there is doubt about biological parentage, obtain genetic testing first. Under RSA 522:4, a result showing the alleged father is not excluded and a probability of 97 percent or higher presumes him to be the father. | - | Before signing an acknowledgment |
| Sign the voluntary acknowledgment of paternity | Unmarried parents who agree sign a voluntary acknowledgment of paternity through the Department of Health and Human Services, recorded with the registrar to establish the parent-child relationship. Attorney review of your matter is available through DocDraft. | - | At the hospital or a local office |
| Track the 60-day rescission window | To cancel a signed acknowledgment, rescind within the federally required 60-day window, unless a related court or administrative proceeding begins first, after which it can be challenged only for fraud, duress, or material mistake of fact. | - | Within 60 days of signing |
| File under the Uniform Act on Paternity if parents disagree | If parents do not agree, bring a proceeding under RSA 168-A in the proper county (RSA 168-A:9). The court can order genetic testing and enter a support order under RSA 458-C. | - | Any time before the deadline |
| Keep records and calendar the eighteen-year deadline | Save copies of the acknowledgment, any genetic-test results, and court papers, and calendar the deadline: a paternity proceeding must be commenced within eighteen years of the child's date of birth (RSA 168-A:12). | - | Ongoing |
Frequently Asked Questions
Establishing paternity in New Hampshire means legally identifying a child's parent so the child can receive support, custody and parenting time, health coverage, inheritance, and benefits. It can be done by signing a voluntary acknowledgment of paternity or through a proceeding under the Uniform Act on Paternity (RSA 168-A).
Parents who agree can sign a voluntary acknowledgment of paternity through the Department of Health and Human Services, usually at the hospital. If parents disagree, either brings a court proceeding under RSA 168-A, where the court can order genetic testing and enter a support order (RSA 522:4, RSA 458-C).
It is a form, sometimes called an affidavit of paternity, that unmarried parents sign to establish the parent-child relationship without going to court. It is provided through the Department of Health and Human Services, completed at the hospital or later, and recorded with the registrar to establish paternity.
Under RSA 168-A:12, no proceeding to establish paternity may be maintained unless it is commenced within eighteen years of the child's date of birth. Because the clock runs from birth, the practical window to bring a court action closes when the child turns 18.
A person is presumed a parent when the child is born to that person's spouse during the marriage, or within 300 days after it ends for any reason (RSA 168-B:2). The presumption may be rebutted in an appropriate action only by clear and convincing evidence, or by a court decree establishing another person's parentage.
Yes, within a short window. Under the federally required rule that applies in every state, a signatory may rescind within 60 days, unless a related court or administrative proceeding begins first. After that the acknowledgment can be challenged only for fraud, duress, or material mistake of fact.
Under RSA 522:4, if genetic tests show the alleged father is not excluded and the probability of paternity is 97 percent or higher, he is presumed to be the father. New Hampshire's 97 percent trigger is lower than the 99 percent threshold that several other states apply.
The Department of Health and Human Services provides the acknowledgment form and, through its child-support program, can help establish paternity and support. When parentage is disputed, the court hears the proceeding under the Uniform Act on Paternity and can order genetic testing (RSA 168-A, RSA 522:4).
Other New Hampshire guides
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