Illinois Custody Laws for Unmarried Parents: Paternity and Support

In Illinois, custody law for unmarried parents starts from a hard rule: the person who gave birth is the only legal parent until paternity is established for the other biological parent.¹ Once paternity is on record, either parent can ask a court to allocate decision-making authority, parenting time, and child support. Nothing about being unmarried limits what a court can order after that point. The gap between biology and legal recognition is what unmarried fathers, in particular, have to close first.

Where Unmarried Parents Start

The Illinois Parentage Act of 2015 creates an automatic parent-child relationship between a child and the person who gave birth.¹ It also presumes parentage for a spouse or civil-union partner of the birth parent, but that presumption requires a marriage or civil union.² An unmarried biological father fits none of the statutory presumptions.

Until paternity is legally established, that unmarried father cannot request parenting time, weigh in on major decisions, or be ordered to pay child support. He also has no standing to object if the birth parent moves the child out of state. The birth parent, by contrast, holds full authority from day one without any filing.

Establishing Paternity

Voluntary Acknowledgment of Parentage

The fastest route is a Voluntary Acknowledgment of Parentage (VAP), typically signed at the hospital after birth. Staff add the signing parent’s name to the birth certificate and forward the form to the Illinois Department of Healthcare and Family Services. Once filed, the VAP has the same legal effect as a court order of parentage.³ Parents who missed the hospital can still complete a VAP later through HFS.

A signatory can rescind the VAP within 60 days of its effective date, or before any court or administrative proceeding involving the child begins, whichever comes first.⁴ After that, challenges require proof of fraud, duress, or a material mistake of fact.

A Court or Administrative Order

When one parent will not sign a VAP, the other can file a petition for a judicial order of parentage in the local circuit court or pursue an administrative order through HFS child support services. Either path can require genetic testing. Court-admissible DNA tests through Illinois-listed laboratories generally run about $150 to $400. A judge can allocate that cost between the parties or waive it for a parent with a fee waiver.

Once a judgment of parentage is entered, the father gains legal standing to seek parenting time and decision-making, and the obligation to pay child support attaches. Rights and financial responsibility arrive together.

The Putative Father Registry

Illinois maintains a Putative Father Registry under the Parentage Act for men who believe they may have fathered a child but have not yet established paternity.⁵ Registering within 30 days of birth protects the right to be notified of any adoption proceedings. A father who misses that window can lose parental rights without ever being contacted. This matters most when communication with the birth parent has broken down.

What “Custody” Means in Illinois Now

Illinois replaced the old custody framework in 2016. There are now two separate things a court allocates: significant decision-making responsibilities, and parenting time. They are decided independently, and one parent can hold a lot of one and little of the other.

Significant Decision-Making

A court assigns authority over four areas:⁶

Education: school choice, tutors, special education.
Health: medical, dental, and mental health treatment.
Religion: religious training and observance.
Extracurricular activities: sports, clubs, organized activities.

These can be split. One parent might handle education and activities; the other might handle health care. Joint decision-making across all four is possible, but courts are cautious about ordering it when the parents have a history of high conflict.⁶

Religion is treated differently. A court allocates religious decision-making based on an express or implied agreement between the parents, or a demonstrated pattern of religious upbringing. Without either, the court will not allocate religious decision-making at all.⁶

Parenting Time

Parenting time is the actual schedule of when the child is in each parent’s physical care.⁷ The law presumes both parents are fit and should have meaningful time with the child. A court will not restrict a parent’s time unless there is evidence that the parent’s contact would seriously endanger the child’s physical, mental, or emotional health.⁸

How Courts Decide

Every allocation runs through the best interests of the child. The factors for decision-making and parenting time overlap but are not identical.

For decision-making, the court weighs the child’s wishes (given maturity), each parent’s past participation in that type of decision, the parents’ ability to cooperate, their level of conflict, and the distance between their homes.⁶ Track record matters. A parent who has handled every doctor’s appointment and school enrollment for years is not likely to lose that authority to a parent who was absent from those decisions.

For parenting time, courts look at a longer list:⁸

Caretaking history during the 24 months before the petition was filed, or since birth if the child is under two.
The child’s wishes, when the child is mature enough to express a reasoned preference.
The child’s adjustment to their current home, school, and community.
Each parent’s willingness to support the other parent’s relationship with the child.
Any violence, threats, or abuse in the child’s household.
Mental and physical health of both parents and the child.

Caretaking history is often decisive. Courts want to minimize disruption to the child’s established routine, so a parent who did most of the day-to-day work typically keeps that role, with structured time for the other parent built around it. Judges look at who actually did the caregiving, not who says they would have.

When a Parent’s Conduct Requires Restrictions

If a parent’s behavior has seriously endangered the child, Section 603.10 gives the court broad authority to restrict parenting time and decision-making. Available restrictions include:⁹

Reducing or eliminating parenting time.
Supervised visitation, including oversight by the Department of Children and Family Services.
Exchanges through an intermediary or in a protected location.
A bar on alcohol or drug use during and immediately before parenting time.
Required completion of abuse treatment, substance abuse treatment, or counseling.
Posting a bond to guarantee the child’s safe return.

The petitioner must show by a preponderance of the evidence that the parent’s conduct seriously endangered the child or significantly impaired the child’s emotional development.⁹

Filing the Case

The Parenting Plan

Parents must submit a parenting plan. The Illinois Supreme Court’s standardized Parenting Plan form is free on the Illinois Courts website and at any circuit clerk’s office, and every circuit court accepts it.¹⁰ The plan needs specifics: a weekly schedule with pickup and drop-off times, holiday and vacation coverage, transportation logistics, how the parents will communicate, which parent’s address governs school enrollment, and how each decision-making area is allocated.

If parents agree, they submit one joint plan. If not, each parent submits their own and the court uses both as a starting point. Vague proposals signal that a parent hasn’t thought through the logistics.

E-Filing, Fees, and Service

Most Illinois counties require electronic filing through the Odyssey eFileIL system.¹¹ Filing fees vary by county and are typically around $300. Fee waivers are available on a sliding scale tied to the Federal Poverty Guidelines, and courts must grant a full waiver to anyone receiving SSI, TANF, SNAP, or General Assistance.¹²

The other parent must be formally served with a summons by a process server or sheriff. If that parent cannot be located after a diligent search, service by publication is allowed but weakens the enforceability of any resulting order. Once served, the respondent has 30 days to appear and respond. A failure to respond can lead to default judgment.

Mediation

Every Illinois circuit maintains a mediation program for parenting disputes, and courts routinely refer contested cases there before trial. A judge can excuse a party from mediation when an impediment exists, such as domestic violence, substance abuse, or a mental health condition that would make the process unsafe or ineffective.¹³

Child Support

Once paternity is established, either parent can seek a support order. Illinois uses an income shares model, looking at both parents’ net incomes rather than just the paying parent’s.¹⁴ The calculation runs in four steps:

Determine each parent’s monthly net income.
Combine those figures.
Look up the basic obligation on the state’s schedule for that combined income and number of children.
Split the obligation proportionally by each parent’s share of the combined income.

The parent with less parenting time usually pays. For very low-income parents, a rebuttable presumption sets a $40-per-month minimum obligation per child, capped at $120 across all children. Parents with no income, those who receive only means-tested benefits, or those who cannot work due to a documented disability or incarceration may qualify for a zero-dollar order.¹⁴ Courts also routinely order health insurance coverage, with uninsured medical costs split in proportion to income shares.

Moving With the Child

Once a parenting order is in place, relocating with the child is governed by Section 609.2. The relocating parent must give at least 60 days’ written notice to the other parent, stating the new address, the move date, and how long the relocation will last.¹⁵

Whether court approval is required depends on distance. A move of 25 miles or less from the child’s current primary residence generally does not require permission, though notice may still be required. An out-of-state move of 25 miles or less keeps Illinois as the child’s home state, but any later move beyond that threshold triggers the full relocation process.¹⁵ Longer moves require either written consent from the other parent or a court order.

If the other parent objects, the court holds a hearing and evaluates whether the move serves the child’s best interests, looking at the reason for the move, the effect on the parenting schedule, and whether a revised schedule can preserve the child’s relationship with both parents.

Changing an Existing Order

Parenting orders can be modified, but the standard depends on what you want to change and how long the order has been in place.

For decision-making, no modification can be filed within two years of the original order unless the petitioner submits an affidavit showing that the child’s current environment may seriously endanger their health or significantly impair their emotional development.¹⁶ After two years, the petitioner must show a substantial change in circumstances and that the change serves the child’s best interests.

Parenting time is more flexible. It can be modified at any time without meeting the serious-endangerment threshold, as long as a change in circumstances makes a new schedule necessary for the child’s best interests.¹⁶ A new work schedule, a change of schools, or a parent’s move can all qualify.

Details Unmarried Parents Often Miss

Passports

Both parents must appear in person and give consent for a child under 16 to receive a U.S. passport.¹⁷ If the other parent will not cooperate or cannot be located, the applying parent has to provide documentation explaining the situation. Handling passport and international travel rights inside the parenting plan avoids that standoff.

Taxes

Only one parent claims the child as a dependent in a given tax year. By default, the parent with more overnights during the year claims the child. If the other parent will claim the child, the custodial parent must sign IRS Form 8332 releasing that claim.¹⁸ Alternating years is a common parenting-plan arrangement. A revocation of a prior release does not take effect until the following tax year.

Social Security

A child with established paternity can receive Social Security benefits based on a parent’s disability, retirement, or death. An eligible child can receive up to half of a living parent’s full benefit, or up to 75% of a deceased parent’s basic benefit.¹⁹ Without a legal parent-child relationship on file, qualifying for these benefits becomes much harder. That alone is a reason to establish paternity even when the father is not seeking parenting time.

1
Illinois General Assembly. Illinois Code 750 ILCS 46/201
2
Illinois General Assembly. Illinois Code 750 ILCS 46/204
3
Illinois Department of Healthcare and Family Services. Illinois Voluntary Acknowledgment of Parentage – HFS 3416B
4
Illinois General Assembly. Illinois Parentage Act of 2015 – Section 307
5
Illinois General Assembly. Illinois Parentage Act of 2015
6
Illinois General Assembly. Illinois Code 750 ILCS 5/602.5
7
Illinois General Assembly. Illinois Code 750 ILCS 5/602.7
8
Illinois General Assembly. Illinois Code 750 ILCS 5/602.7
9
Justia Law. Illinois Code 750 ILCS 5 Part VI – Allocation of Parental Responsibilities
10
Office of the Illinois Courts. Divorce, Child Support, and Maintenance
11
Illinois Courts. How to e-File
12
Illinois Courts. Illinois Court Fee Waivers Overview
13
Illinois Courts. Illinois Supreme Court Rule 905 – Mediation
14
Illinois General Assembly. Illinois Code 750 ILCS 5/505
15
Illinois General Assembly. Illinois Code 750 ILCS 5/609.2
16
Illinois General Assembly. Illinois Code 750 ILCS 5/610.5
17
U.S. Department of State. Apply for a Child’s Passport Under 16
18
Internal Revenue Service. Release/Revocation of Release of Claim to Exemption for Child by Custodial Parent
19
Social Security Administration. Benefits for Children