“It cannot now be doubted that the Due Process Clause of the 14th Amendment protects the fundamental right of parents to make decisions concerning the care, custody, and control of their children.” – Troxel v. Granville (US Supreme Court)
Paternity is the process of determining whether a man is the legal father of a child. Once paternity is legally established, it gives rise to parental rights and responsibilities, including parenting time and child support, and legal and physical custody may be determined or modified. In Indiana, paternity can be established two ways:  by executing a paternity affidavit in accordance with the law, or  by filing a paternity action in court.
A paternity affidavit must be executed on a form provided by the state department. The paternity affidavit is valid only if the affidavit is executed as follows: (1) If executed through a hospital, the paternity affidavit must be completed not more than seventy-two (72) hours after the child’s birth; (2) If executed through a local health department, the paternity affidavit must be completed before the child has reached the age of emancipation. The paternity affidavit must include sworn statements from both the mother and person identified as the father in the paternity affidavit that the alleged father is the child’s biological father. The mother is automatically granted primary physical custody and sole legal custody upon a child’s birth when she is not married. If a paternity affidavit is properly completed, then it automatically establishes a man’s paternity. Paternity affidavits can be difficult to rescind once executed. If a man requests that a court order a genetic test within 60 days of the paternity affidavit’s execution and the genetic test excludes him as the father, the paternity affidavit can be withdrawn. After 60 days of the paternity affidavit’s execution, a court has to  determine that fraud, duress, or material mistake of fact existed in the execution of the paternity affidavit AND  a genetic test ordered by an alleged father excludes him as the father in order to rescind a paternity affidavit.
A paternity action is initiated by filing a petition with a court. A number of different people can file a paternity petition, including a man alleging to be a child’s father, the mother, the child, and the State. A man is presumed to be a child’s biological father if: (1) the (A) man and the child’s biological mother are or have been married to each other, and (B) child is born during the marriage or not later than three hundred (300) days after the marriage is terminated by death, annulment, or dissolution; (2) the (A) man and the child’s biological mother attempted to marry each other by a marriage solemnized in apparent compliance with the law, even though the marriage (i) is void under IC 31-11-8, or (ii) is voidable under IC 31-11-9, and (B) child is born during the attempted marriage or not later than three hundred (300) days after the attempted marriage is terminated by death, annulment, or dissolution; or (3) the man undergoes a genetic test that indicates with at least a ninety-nine percent (99%) probability that the man is the child’s biological father. Any party to a paternity action can move the court for a blood or genetic test. If a man is found by the court to be the child’s legal father, then the issues of support, custody, and parenting time are addressed in a similar fashion as a divorce. A support order: (1) may include the period dating from the birth of the child, and (2) must include the period dating from the filing of the paternity action.