Family & Safety

Sometimes the father of a child is unknown. A paternity test compares the DNA of a child, the mother, and the alleged father to see if the man is or is not the biological father of a child. 

This can come up in a number of legal contexts. For example, a mother may wish to seek child support Money paid by a parent to help another parent support a minor child or an adult child with a disability from a father. If the man claims he is not a parent, she may seek a paternity test to confirm he is the biological father. Conversely, a man may seek a paternity test to demonstrate that he is not the child’s father. A man may also seek a paternity test to establish that he is the father and that he is entitled to custody of or visitation Time spent between a child and a person who is not the parent with a child. A court also has the authority to mandate a paternity DNA test in accordance with the Illinois Parentage Act.  Sometimes, a judge may order a DNA sample to be taken from other people, like grandparents, siblings, or other relatives. 

Paternity tests must be done by an expert from an accredited laboratory. "At home" kits are not allowed. 

There are three steps in a DNA paternity test. First, the DNA examiner determines whether the child and the alleged father have shared or common DNA. Second, if there is shared or common DNA, the examiner will calculate the paternity index. The paternity index is expressed as a number that indicates that the alleged father is “that many more times likely to be the father.” For example, a paternity index of 1,000 means that it is 1,000 times more likely that the alleged father produced a child with the mother than a random man of the alleged father’s race. Third, the DNA examiner will use a math formula to translate the paternity index “into a percentage that is more understandable” and prepare a written report of the paternity test results. To establish paternity, Illinois courts require DNA test results to have at least a 99.9% probability of paternity. 

If you request a DNA test, you may have to pay for it. You can also ask the judge to split the cost between you and the other party A person or business involved in a court case in a role like plaintiff, petitioner, defendant, respondent, or intervenor. . If you have a fee waiver, you can ask the judge to let you not pay.

Once you have a DNA test establishing paternity, be sure to ask the judge to enter an order of paternity and get a copy of it.