When Do Parents Need to Establish Paternity in Illinois?

 Posted on July 30, 2025 in Parentage

Traditionally, families have consisted of two married parents of the opposite sex who share one or more children. However, even though this type of "nuclear family" may be thought of as the default situation, it is becoming less and less common in the United States. Many couples build lives together and have children without getting married.

Furthermore, married couples get divorced and remarried, and people have children with multiple different married or unmarried partners. When adding issues such as same-sex relationships and single parenthood into the mix, it can seem like there are endless different types of family configurations.

Regardless of how a family is structured, it can be important to establish and safeguard the legal relationships between parents and children. While this may not be an issue for parents who are married when their child is born, parents in other situations may need to take steps to establish paternity. This can provide benefits for the child as well as the parents. However, the procedures followed in these cases are not always clear, especially if disputes arise between parents about the identity of a child’s father or the role that each parent should play in the child’s life.

To ensure that the legal issues related to paternity will be addressed correctly, it is important for a parent to work with a skilled family law attorney. The team at Weiss-Kunz & Oliver, LLC understands the legal issues involved in paternity cases, and our Elmhurst, IL paternity lawyers can provide the guidance and representation needed to ensure a positive outcome for all concerned. Our goal is to protect the best interests of children involved in paternity cases and provide parents with the tools they need to raise children successfully.

Understanding Paternity Under Illinois Law

In Illinois, paternity is actually known as "parentage," and it refers to a legal parent-child relationship. In general, a woman may be presumed to be a child’s parent if she gives birth to the child, unless she had signed a surrogacy agreement and agreed to give up the child to other parents. A woman may also become a child’s parent by legally adopting the child.

A man is presumed to be the parent of a child if he meets one of the following requirements:

• The presumed parent was legally married to the mother of the child, and the child was born during the couple’s marriage.

• The presumed parent had previously been legally married to the child’s mother, and the marriage ended at any point within 300 days before the child’s birth. This presumption will be used in cases where a marriage ended through divorce, when a couple became legally separated, or when the father died.

• A couple agreed to be married or entered into a similar legal relationship, but the marriage was later determined to be invalid, and the child was born within 300 days after the marriage was declared invalid or ended through other means.

• The presumed parent married the child’s mother after the child was born and agreed to be named as the father on the child’s birth certificate.

Notably, these presumptions apply to both men and women, and a woman who is not a child’s biological parent can be presumed to be a child’s legal parent if she meets one of the above requirements. For example, if a child’s mother is married to a same-sex partner, her spouse will be presumed to be the child’s legal parent.

In situations where these presumptions have not been met, the child’s biological mother will be considered the only legal parent, even if another parent is also listed on the child’s birth certificate. In cases where parents are unmarried, the father will not automatically be recognized as the child’s parent, and if paternity is not legally established, he may struggle to protect his rights as a father if his relationship with the child’s mother ends in the future.

How Is Paternity Established?

In situations where a child does not have two presumed parents, steps will need to be taken to legally establish parentage. The easiest way to do so is by completing and filing a Voluntary Acknowledgment of Paternity (VAP). This form must be signed by both parents and filed with the Illinois Department of Healthcare and Family Services (HFS). At the time of the child’s birth, parents can often complete the form at the hospital with the assistance of trained staff. A VAP can also be submitted at any time after a child’s birth, and parents may obtain the form from HFS, the county clerk, or other offices of the Department of Human Services.

It is important for parents to be certain about the identity of a child’s father before signing and submitting a VAP. After a form has been submitted, there is a limited window of time for a parent to rescind their voluntary acknowledgment. Typically, a rescission of a VAP must be submitted within 60 days after the date the VAP was originally signed. It may be possible to challenge paternity at a later date, although doing so can be difficult. To ensure that the rights of the parents and the child will be protected, parents may wish to perform paternity testing prior to signing a VAP.

Paternity testing may also be used when parentage is established through other means. This is often necessary when parents disagree about a child’s parentage or when the identity of a child’s biological father is uncertain. In some cases, parents may agree to work with Illinois Child Support Services to establish paternity administratively. In these situations, HFS personnel may work with the parents to gather information that may be used to identify the child’s father. They may conduct interviews with both parents to determine whether they are in agreement about the identity of the father or whether the timeline surrounding the child’s conception indicates parentage. In these situations, once paternity has been verified, an Administrative Order of Paternity will be created that will establish a legal relationship between the father and the child.

In more contentious situations, such as when one parent refuses to acknowledge parentage, a legal paternity case may need to be initiated. A parent or another interested party may file a petition to establish parentage with the county court. In these cases, a judge will typically order the parents and the child to submit to genetic testing. These tests will usually be based on a saliva swab, and a medical lab will compare the DNA of the child and the alleged father. If the tests find that there is at least a 99.9 percent probability that the man is the child’s father, a legal paternity order will be issued.

What Are the Benefits of Establishing Paternity?

The establishment of legal parentage can provide multiple benefits for all parties involved. For fathers, legal recognition as a child’s parent will ensure that they can have an ongoing relationship with the child, be involved in making important decisions about how the child will be raised, and have the right to spend time with the child on a regular basis. This will ensure that a person’s parental rights will be protected and that a father will be an important part of the child’s life, regardless of the status of his relationship with the child’s mother.

Once paternity has been established, parents can work together to address matters related to child custody and ensure that their child is raised in an environment that supports their health, safety, and well-being. A child custody order will address the allocation of parental responsibilities, which involves making decisions about the child’s upbringing in areas such as education, medical care, and religion. Depending on the parents’ relationship and each parent’s level of involvement in the child’s life, decision-making authority may be shared equally, or one parent may be able to make certain decisions without the need for the other parent’s approval. Parenting time schedules will also be established that will allow both parents to spend regular time with the child on an ongoing basis. Even if all parental responsibilities are allocated to one parent, the other parent will generally be presumed to be fit and able to provide care for the child when necessary, and they will be able to spend reasonable amounts of time with the child, as long as this would not put the child at risk of suffering physical or emotional harm.

Because a child’s legal parents are required to provide for the child’s needs, the establishment of paternity will allow child support orders to be created. These orders will be based on the income earned by both parents, and child support paid by one parent to the other will address the child’s ongoing needs, including nutrition, clothing, and a place to live. Additional child-related expenses may also be addressed, including medical and educational costs, child care that is needed while a parent is working, and fees or supplies for extracurricular activities the child will participate in.

Aside from the benefits they receive through financial support and involvement by both parents in their lives, the establishment of paternity can have a positive impact on a child in a number of other ways. A legal relationship with a parent will give a child the right to inherit money or property after a parent’s death. They will also be able to receive certain types of benefits through a parent, such as Social Security or benefits provided to military veterans. A child may also be able to access family medical history to ensure that they can receive proper medical treatment. Knowing the identities of their parents can also benefit a child emotionally by giving them a better understanding of their roots and the history of their family.

False Claims of Paternity in Illinois

In some cases, paternity is not just unknown; it is misrepresented. False claims of paternity can arise when a mother incorrectly or knowingly identifies the wrong man as her child’s biological father. These situations can have profound legal and financial consequences, especially if the man signs a Voluntary Acknowledgment of Paternity without confirming biological parentage through DNA testing.

Under the Illinois Parentage Act of 2015 (750 ILCS 46), once a man is legally recognized as a child’s parent, either by signing a VAP or through a judicial finding, he becomes legally responsible for child support, regardless of later doubts or regrets. If a man discovers after the fact that he is not the biological father, reversing that legal determination can be incredibly difficult.

Rescission of a VAP must typically occur within 60 days of signing. After that window closes, challenging paternity requires filing a petition to vacate or challenge the acknowledgment based on fraud, duress, or material mistake of fact. Courts are hesitant to disturb a legal parent-child relationship once it is established, particularly if the child has developed a bond with the presumed father.

Genetic testing plays a central role in these cases. If ordered by the court or pursued during administrative proceedings with the Illinois Department of Healthcare and Family Services, DNA evidence can definitively confirm or disprove biological paternity. In contested cases, the court will weigh the results alongside the child’s best interests, which may still favor maintaining the legal relationship despite contrary test results.

For men who have been wrongfully named as a child’s father and ordered to pay child support, these proceedings are emotionally and financially draining. Unfortunately, until a legal judgment is vacated, child support obligations remain enforceable and unpaid support can accumulate rapidly, leading to wage garnishment, tax refund seizure, or even driver’s license suspension.

If you believe you have been falsely named in a paternity case, you must act quickly. Do not sign any documents without legal counsel, and avoid informal agreements that lack legal standing. One of our experienced family law attorneys can help you navigate the options for genetic testing, represent you in court proceedings, and protect your financial rights under Illinois law.

Contact Our DuPage County, IL Paternity Attorneys

For many parents, legally establishing paternity is an important step in ensuring that their child’s best interests will be protected. It can ensure that parents will be able to be closely involved in their child’s life, have a say in how the child is raised, and spend time with them on a regular basis, no matter the status of the relationship between the parents in the future. By establishing paternity, parents can also make sure their child will have the necessary financial resources to grow up successfully. However, there are a number of legal complications that can arise as parents address issues related to paternity, and it is important to work with an experienced family law attorney to make sure all legal matters are handled correctly.

If you have questions about the best ways to address issues related to parentage while making sure to protect your parental rights and providing for your child’s best interests, the Elmhurst, IL paternity lawyers at Weiss-Kunz & Oliver, LLC can provide the legal help you need. To set up a consultation and learn more about how we can assist with these issues, call our office at 312-605-4041. We look forward to helping you address and resolve any family law concerns that you face.