by 
Fathers may be obligated to pay child support even when children are not biologically theirs. It may be possible to challenge paternity when a DNA test shows someone else is the father. The man has limited time to refute paternity. Otherwise, he could remain obligated to support the child.
Establishing Paternity in Illinois
According to Illinois law, if a woman gives birth to a baby and was married or in a civil union at the time of birth or within 300 days of the birth, the man in the relationship is legally presumed to be the father. But if the parents are unwed, paternity is either established by signing a Voluntary Acknowledgement of Paternity (VAP), through an Administrative Paternity Order, or a court’s Order of Paternity. When a man is presumed, has signed a VAP, or been designated by the court to be a child’s father, he can be ordered to provide child support and possibly medical coverage.
How Would Paternity Be Challenged?
Within 60 days of signing, any parent on a VAP could file a rescission. If there is a dispute of whether the man is the father, DNA testing may be ordered by the court to determine paternity to establish child support.
A husband that is not the biological father can sign a Denial of Paternity form within two years of when the child was born to relieve himself of child support obligations.
Parental status can also be rescinded based on fraud, duress or material mistake of fact. To establish that fraud was committed, the man must be able to prove to the court that the child’s mother knew he was not the father, that he was intentionally deceived, and that misrepresentation was committed.
Even with proof, the court may choose not to reopen a child support proceeding. It may require legal proof of who actually fathered the child. Because it is the court’s responsibility to rule in the best interests of a child, the presumed father may be required to continue support unless the biological father accepts the responsibility.
If a father finds out that a child is not biologically his years later, it is likely he would not be reimbursed for the child support he has paid. He may be required to continue paying support until the child reaches the age of 18 or finishes his or her education.
