How to Establish Paternity in Illinois

Illinois law uses the broader term parentage for the legal parent-child relationship. Under 750 ILCS 46/102, that relationship extends equally to every child regardless of the parents' legal relationship. Marriage or related presumptions, a voluntary acknowledgment and a court judgment are three main routes, though 750 ILCS 46/201(a) recognizes other ways as well.

Under 750 ILCS 46/204, a marriage-based presumption includes a child born during the marriage or within 300 days after it ends by death, invalidity, dissolution or legal separation. The presumption also applies to a civil union or substantially similar relationship. Other listed situations also qualify. An existing presumed, acknowledged or adjudicated parent is an important fact when considering which route applies.

The statutory name is Voluntary Acknowledgment of Parentage, often called a VAP. It is not simply a statement about biology. A valid, filed VAP establishes legal rights and duties under 750 ILCS 46/305.

1. Required signers. Under 750 ILCS 46/301 and 750 ILCS 46/302, the person who gave birth and the person seeking to establish parentage sign the acknowledgment.
2. Legal effect. The acknowledgment states that the signers understand it is equivalent to a judicial adjudication of parentage.
3. Signing requirements. The acknowledgment must be in a record, signed under penalty of perjury and witnessed.
4. Filing. The statute provides for filing with the Department of Healthcare and Family Services. Under 750 ILCS 46/304(c), the acknowledgment takes effect on filing. There is no filing fee for a VAP under 750 ILCS 46/306.
5. Limited ability to undo. Signing and filing create legal consequences, with limited opportunities to undo the acknowledgment, as described below.

Under 750 ILCS 46/307, a signer may rescind by filing a signed, witnessed rescission with the Department of Healthcare and Family Services before the earlier of 60 days after the VAP takes effect or the date of a judicial or administrative proceeding relating to the child in which that signer is a party.

After that period, 750 ILCS 46/309 permits a challenge only for fraud, duress or material mistake of fact, by verified petition within 2 years of the acknowledgment's effective date. Under 750 ILCS 46/302(a)(5), the acknowledgment itself states that a challenge is barred after 2 years unless the period is tolled. The challenger must prove the claim by clear and convincing evidence. While a challenge is pending, the court generally may not suspend legal responsibilities such as child support.

A court proceeding provides a route to a parentage judgment when the issue requires judicial review. The steps below describe the statutory framework, not instructions for a particular case.

1. Who may file. Under 750 ILCS 46/601 and 750 ILCS 46/602, authorized petitioners include the child, the person who gave birth, a pregnant person, a presumed or alleged parent, and, in specified circumstances, the Department of Healthcare and Family Services.
2. Verified petition. The petition asks the court to adjudicate parentage. Existing acknowledgments, presumptions and judgments are important to review.
3. Proper county. Under 750 ILCS 46/604(a), parentage venue is any county where a party resides. Under 750 ILCS 46/604(b), a proceeding for allocation of parental responsibilities begins in the county where the child resides.
4. Service. The service date matters because 750 ILCS 46/802(a) states that child support under the applicable guidelines commences on the date summons is served.
5. Genetic testing. Court-ordered testing is governed by 750 ILCS 46/401 and 750 ILCS 46/402. Existing legal parentage also affects admissibility under 750 ILCS 46/614.
6. Judgment. Under 750 ILCS 46/802, the judgment adjudicates parentage, must contain or expressly reserve child support provisions, and may contain or reserve parenting provisions.

Our paternity lawyer in Chicago page explains the firm's parentage services.

Under 750 ILCS 46/401, a court may order DNA testing. On a party's request, the court must order testing unless it determines that the conduct of the presumed, acknowledged or adjudicated parent estops that parent from denying parentage, disproving parentage would be inequitable, and denying testing serves the child's best interests. Genetic testing may not be used to challenge the parentage of a parent under Article 7 (assisted reproduction) or the Gestational Surrogacy Act, or to establish a donor's parentage (750 ILCS 46/401(c)). In plain language, the court considers prior conduct, fairness and the child, not biology alone.

Under 750 ILCS 46/402, testing is performed by a court-appointed qualified expert in a laboratory accredited by the American Association of Blood Banks or its successor.

A private test does not necessarily resolve the legal issue. Under 750 ILCS 46/614, when a child already has a presumed, acknowledged or adjudicated parent, test results are inadmissible to adjudicate parentage unless testing occurred with the required consent of both the person who gave birth and that parent, or by court order under 750 ILCS 46/401.

An existing legal parent-child relationship can change how testing and a parentage challenge must be handled.

Parentage, child support, parenting time and decision-making are connected but distinct. A valid VAP confers parental rights and duties under 750 ILCS 46/305, but a VAP alone does not set a parenting schedule. See whether signing a VAP gives parenting time in Illinois.

Under 750 ILCS 46/802(a), guideline child support commences on the date summons is served. Under 750 ILCS 46/802(e), the court may also order support for a period before filing after considering the listed factors. Our Chicago child support lawyers page addresses support representation.

The wording of the judgment matters. Under 750 ILCS 46/802(c), without an explicit allocation order, establishing support or allocating parenting time to one parent is construed as allocating all parental responsibilities to the other parent.

If the parentage order contains no such provisions, the statute presumes all parental responsibilities are allocated to the mother. That presumption does not apply if the child resided primarily with the other parent for at least 6 months before the mother seeks enforcement. Our Chicago child custody lawyers page covers parenting representation.

Mothers, fathers and other parents may need help understanding which legal relationship exists and what remains unresolved. Our Chicago fathers' rights information discusses representation for fathers facing family law issues.

• Treating a VAP as informal paperwork instead of a legally effective acknowledgment.
• Assuming the rescission period always remains open for 60 days despite a related proceeding.
• Assuming a private DNA test automatically changes legal parentage.
• Confusing legal parent status with a court-ordered parenting schedule.
• Ignoring an existing presumed parent or an earlier parentage judgment.
• Overlooking support and allocation provisions when reviewing the final order.

These misunderstandings concern different parts of the process. A signing issue may involve acknowledgment deadlines, while a parenting dispute may require allocation provisions. Identifying the actual issue helps frame the questions to discuss with a lawyer.

Consider legal review when parentage is disputed, a VAP deadline may apply, another legal parent exists, or support and parenting provisions remain unresolved. At Chicago Family Attorneys LLC, we focus only on family law. Managing attorney Aaron Korson has been licensed in Illinois since 2019.

Limited-scope representation is a flat fee for a defined task, quoted after a consultation and usually paid up front, though in some cases in two installments.

Full representation starts with an initial payment of $1,500 to $2,500, followed by $500 to $650 per month beginning 30 days after the initial payment while representation remains active. It covers drafting, hearings, motions and phone calls within the agreed scope.

Court filing costs, expert fees, service costs and evaluation costs are separate. The client pays them and the firm does not advance them. The written agreement confirms the fee, covered work and expenses before engagement. Fee ranges shown are not a quote for your matter. Call 312-965-5618 for a quote.

Review paternity lawyer costs in Chicago, limited-scope family lawyer costs and our family law pricing overview.

For a consultation, useful topics include any existing acknowledgment or judgment, the parents' marriage history, relevant filing or service dates, and unresolved support or parenting questions. These details help identify which issues need review.

The firm serves Cook, DuPage, Lake and Will counties. Our office is at 53 W Jackson Blvd, Suite 752, Chicago, IL 60604. Initial consultations are free for people seeking to hire an attorney. This guide provides general information, not personal legal advice.

Book a free consultation. Call 312-965-5618.

• 750 ILCS 46/201: Establishment of the parent-child relationship
• 750 ILCS 46/204: Presumption of parentage
• 750 ILCS 46/301: Voluntary acknowledgment of parentage
• 750 ILCS 46/305: Effect of voluntary acknowledgment
• 750 ILCS 46/307: Rescission of voluntary acknowledgment
• 750 ILCS 46/309: Challenge after the rescission period
• 750 ILCS 46/401: Genetic testing
• 750 ILCS 46/802: Judgment of parentage
• 750 ILCS 46/102
• 750 ILCS 46/205
• 750 ILCS 46/302
• 750 ILCS 46/304
• 750 ILCS 46/306
• 750 ILCS 46/402
• 750 ILCS 46/601
• 750 ILCS 46/602
• 750 ILCS 46/604
• 750 ILCS 46/614

Bring your questions and the documents you have. The initial consultation is free for people seeking to hire an attorney, and the firm confirms its fee and the covered work in writing before you engage it. Call 312-965-5618 or book online.