The Illinois Parentage Act of 2015 (750 ILCS 46), Explained

What the Parentage Act covers

The Illinois Parentage Act of 2015 took effect January 1, 2016, and section 977 repealed the Illinois Parentage Act of 1984. Section 104 says it applies to determinations of parentage in Illinois. Section 102 says a child has the same rights to parentage regardless of the parents' marital status, age, gender, gender identity or sexual orientation, or the circumstances of the child's birth. Public Act 104-448 amended the Act effective December 12, 2025, and its changes to the voluntary acknowledgment sections took effect January 1, 2026, so older summaries may use outdated wording.

The Act is organized into nine articles: general provisions, the parent-child relationship, voluntary acknowledgment, genetic testing, temporary relief, proceedings to adjudicate parentage, children of assisted reproduction, support and judgment, and miscellaneous provisions. Section 201 lists the ways a parent-child relationship is established: by giving birth (except as the Gestational Surrogacy Act provides), by a presumption under section 204, by an effective voluntary acknowledgment, by a court adjudication, by adoption, by consent to assisted reproduction, or under the Gestational Surrogacy Act.

Sections you are most likely to see

Presumptions of parentage

Section 204 says a person is presumed to be a child's parent in four situations:

• The person was married to, or in a civil union with, the person who gave birth when the child was born.
• The child was born within 300 days after that marriage or civil union ended by death, divorce, invalidity or legal separation.
• The couple attempted a marriage or civil union that could be declared invalid, and the child was born during it or within 300 days after it ended.
• The couple married after the birth, and the person agreed in writing to be named on the birth certificate.

A presumption is not the final word. Section 206 says a person challenging it must use clear and convincing evidence. Under section 608, anyone other than the child must bring that challenge within 2 years after the person knew or should have known the relevant facts, with time excluded for legal disability, duress or fraudulent concealment. The child is not bound by that 2-year limit. Section 608(b) allows a challenge at any time if the court finds the presumed parent and the birth parent did not live together or have sexual intercourse during the probable time of conception.

Section 205(c) separately lets a person who was adjudicated a parent based on a presumption ask to undo the adjudication if DNA testing shows they are not the parent. That petition is due within 2 years after the person learns the relevant facts, and never after the child turns 18.

Voluntary acknowledgment and genetic testing

The Voluntary Acknowledgment of Parentage

Many unmarried parents sign a Voluntary Acknowledgment of Parentage (VAP), often around the time of the birth. Under section 302, the form must be signed under penalty of perjury by the birth parent and the person establishing parentage, and it must be witnessed. It must state that the signers understand it is the equivalent of a court judgment of parentage. Section 304 says it takes effect when filed with the Illinois Department of Healthcare and Family Services (HFS), and section 305 gives it the full force of a judgment, including as a basis for child support.

A signer can rescind a VAP under section 307 by filing a signed, witnessed rescission with HFS. The deadline is the earlier of 60 days after the VAP took effect or the date of a court or administrative proceeding about the child in which the signer is a party. After that, section 309 allows a challenge only for fraud, duress or material mistake of fact, by verified petition within 2 years, proven by clear and convincing evidence. During the challenge, the court generally may not suspend the signer's duties, including child support. Our post on whether signing a VAP gives parenting time explains what the form does not do.

Genetic testing

Section 401 lets a court order DNA testing of the child, the birth parent and an alleged, presumed, acknowledged or adjudicated parent. On a party's request, the court must order testing unless it finds that the parent's conduct bars a denial of parentage, that disproving the relationship would be inequitable, and that denying the test is in the child's best interests. Under section 404, results showing a combined parentage index of at least 1,000 to 1 and a probability of at least 99.9% create a presumption of parentage. Section 405 says the party who asks for testing pays unless the court divides the cost, and section 615 lets the court decide parentage against a person who refuses court-ordered testing.

Who can file and the deadlines

Section 602 says a parentage case starts with a verified petition. It may be filed by the child, the birth parent, a pregnant person, a person presumed or alleged to be the parent, a support-enforcement agency, a person or agency caring for or supporting the child, HFS, an adoption or child welfare agency, a legal representative, or an intended parent. Under section 604, the case can be filed in any Illinois county where a party lives, while a request to allocate parental responsibilities is filed where the child lives.

Deadlines depend on whether the child already has a legal parent. Under section 607, if the child has no presumed, acknowledged or adjudicated parent, a case may be filed at any time, and an adult child may file. If there is a presumed parent, section 608 applies. If there is an acknowledged or adjudicated parent, section 609 limits challenges by signers to the section 309 window and gives others 2 years from the acknowledgment or judgment.

After parentage: support, parenting time and decision-making

Section 801 lets a court order temporary child support while the case is pending if a party shows parentage by clear and convincing evidence. Section 802 says the judgment must contain or expressly reserve child support, and may address parental responsibilities, parenting time and security for payment. The court applies the standards of the Illinois Marriage and Dissolution of Marriage Act and the section 505 guidelines. Support is ordered to start on the date the summons was served, and section 802(e) allows support for a period before the case was filed after weighing listed factors. If the case is filed within 2 years after the birth, the judgment may also address pregnancy and delivery expenses.

Section 802(c) contains a rule many parents miss. If a parentage judgment does not expressly allocate parental responsibilities, an order that makes one parent pay child support, or that gives one parent parenting time, is treated as giving all parental responsibilities to the other parent. If the judgment has none of those terms, all parental responsibilities are presumed to belong to the mother, unless the child has lived mainly with the other parent for at least 6 months before she seeks to enforce the judgment. Section 808 says later changes follow the divorce statute, and section 809 lets the court order fees under section 508. Section 801(d) also requires a termination date in every support order; see when child support ends in Illinois.

How a parentage case moves in Cook County

1. Start the parentage action by filing a verified petition in the Domestic Relations Division of the Circuit Court of Cook County, which hears parentage cases. Its main courthouse is the Richard J. Daley Center.
2. Serve the other parent. If parentage is disputed, ask for genetic testing under section 401.
3. If parenting time or decision-making is at issue, Illinois Supreme Court Rules 923 and 924 call for a case management conference within 90 days after service and a parenting education program. Disputed parenting issues go to mediation under Rule 905, which covers paternity cases. See whether mediation is mandatory.
4. Ask for temporary support under section 801 if needed, and exchange financial information.
5. Resolve the case by agreement or hearing, ending with a judgment under section 802.

Bring the child's birth certificate, any signed VAP, any existing orders, proof of income, and a record of who has cared for the child and where the child has lived.

Common mistakes

• Believing a VAP sets a parenting schedule. It establishes parentage; parenting time and decision-making need a court order.
• Missing the 60-day rescission window or the 2-year challenge period.
• Stopping support while a challenge is pending.
• Accepting a judgment that is silent on parental responsibilities without understanding section 802(c).
• Waiting years to file, which can affect the past-support analysis under section 802(e).

The other parent can contest parentage, ask for testing, raise the time limits or estoppel factors in section 610, and propose a different parenting plan.

How Chicago Family Attorneys can help

• Explain how the Parentage Act applies to your family, including presumptions and VAP questions.
• Prepare and file parentage petitions, responses and requests for genetic testing.
• Seek or respond to child support, parenting time and decision-making requests.
• Represent mothers and fathers in Cook, DuPage, Will and Lake Counties.
• Offer limited scope help: document drafting from $500 or one hearing appearance from $1,200.

Full representation starts with an initial payment of $1,500 to $2,500, then $500 to $650 per month beginning 30 days after the initial payment while representation remains active. See the paternity cost page, our Chicago paternity services page, our guide on how to establish paternity in Illinois, fathers' rights, and our overview of Illinois parental rights.

This article is general information about Illinois law, not legal advice for your situation, and it does not predict the outcome of any case.