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Establishing Paternity

Authored By: Lagniappe Law Lab

How Paternity is Determined

Different laws apply to paternity depending on the marital status of the child's parents.  There are three broad categories: 

  1. child born to married parents;
  2. child born to divorced parents and within 300 days from the judgment of divorce; or
  3. child born to unmarried parents. 

Because the child's paternity status depends on the parents' marital status, a child can sometimes have a "legal father" who is different from their biological father.

The law provides ways to for a man to establish or challenge paternity.  Mothers and children can also establish or challenge a man's paternity. The law uses the word "disavow" to describe a challenge to paternity. 


Child Born to Married Parents or Divorced Parents Within 300 Days from the Judgment of Divorce

A child born to married parents, or within 300 days after a judgment of divorce, is "presumed" to be the child of the husband.  This means the husband of the mother is the "legal father" at the time the child is born, even if he is not the biological father. 

Of course, a legal father who learns or suspects he is not the biological father can disavow (challenge) paternity. If the mother has remarried, the law allows the new husband to acknowledge paternity and the divorced husband to disavow paternity. Click on the tab above titled "Married or Divorced Parents," for more information on how to establish or disavow paternity in cases where the child was born to married parents or divorced parents within 300 days from the judgment of divorce. 


Child Born to Unmarried Parents

A child born to unmarried parents has no "presumed" father. The law only recognizes the mother as the child's parent and paternity must be established in these cases. Click on the tab above titled "Unmarried Parents," to learn about how to establish paternity of a child born to unmarried parents. 


Special Situation: Adoption

Upon adoption, the adopting parent becomes the parent of the child for all purposes. The filiation between the child and his legal parent is terminated, except as otherwise provided by law.  The adopted child and his descendants retain the right to inherit from his former legal parent and the relatives of that parent.


 

Establishing Paternity: Married or Divorced Parents

For children born of married parents, or within 300 days after a judgment of divorce, the husband of the mother is the "presumed" father of the child.  He is the legal father under this "presumption of paternity".  The husband is considered the father unless a different biological paternity is established as provided by law. 

In cases where the husband (or former husband) is not the biological father, the law provides several ways to change the child's paternity. 


Three-Party Acknowledgement 

When a child is born to married parents, but a blood or tissue test shows that a child's biological father is a different man (that is, not the husband or former husband), a "three-party acknowledgment" can declare the true paternity.  

  • The biological father, the mother, and the mother's husband (or former husband) all three sign the acknowledgment.  
  • The "three-party acknowledgement" states that the husband is not the child's father and the biological father is the child's father.  
  • The three-party acknowledgment must be by "authentic act," which means it must be signed by each party in front of a notary. 

A three-party acknowledgment must be signed within ten years after the date of birth of the child and within one year from the child's death, whichever is sooner. 


Biological Father's Action to Establish Paternity

When the former husband is presumed to be the father of the child, but the former husband will not agree to sign a three-party acknowledgment, the biological father can file a lawsuit asking the Court to establish his paternity.  In this situation, the biological father's case to establish paternity must be filed within one year from the date of the child's birth.  However, in cases where the mother in bad faith deceived the father of the child about his paternity, the case to establish paternity must be filed within one year of the day the father knew or should have known of his paternity, but no later than ten years from the day of the child's birth. 


Child's Action to Establish Paternity

A child may ask the Court to prove paternity even though he is presumed to be the child of another man.  This kind of case has to be filed within one year from the death of the alleged father, for the purposes of succession.  


Paternity When a Divorced Mother Has Remarried

First Husband Disavows; Second Husband Presumed Father

If a child is born within three hundred days from the day of the termination of a marriage and his mother has married again before his birth, the first husband is presumed to be the father.  If the first husband gets a judgment of disavowal of paternity, the "second husband" is presumed to be the father.

Mother's Action for Contestation and Establishment of Paternity

The mother of a child can file a case for "contestation and establishment of paternity" to ask the Court to establish both that:

  1. her former husband is not the father of the child and
  2. that her present husband is the father.

A mother can only file this kind of paternity case if the present husband has acknowledged the child by authentic act.  Still, the mother must prove by clear and convincing evidence that the present husband is the father of the child.  In general, a mother must file this kind of case within one hundred eighty (180) days from the marriage to her present (second) husband and also within two (2) years from the day of the birth of the child.


Presumed Father's Action for Disavowal of Paternity

A husband legally presumed to be the father may disavow paternity by showing a court clear and convincing evidence that he is not the father, unless the parents used assisted conception. The father only has one year from the birth of the child (or one year from the day he knew or should have known that he was not the biological father, whichever occurs later) to file a disavowal case with the court.  But, if the husband lived separate and apart for the 300 days before the date of the child's birth, the one year time to file a disavowal case starts when he is notified in writing that a person with an interest has asserted he is the father of the child. 

Once the presumed father has disavowed paternity, a man can establish paternity by formal acknowledgment.


 

Paternity of a Child Born Outside of Marriage

Child Born Outside of Marriage

For children born outside of marriage, there is no presumption of paternity. Under Louisiana law, when a child is born to an unmarried woman, she is the only legally recognized parent. This is true even if the mother and father are living together, or are in a committed relationship. Paternity has to be established.

Acknowledgment by Authentic Act

Biological Father's Action to Establish Paternity

A man may ask a court to establish his paternity of a child at any time if the child is not filiated to another man (born outside of a marriage).

Related Resources: 

Last Review and Update: Oct 29, 2021
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