Illinois Stepparent Adoption Guide 2026: Complete Steps

The short answer: in Illinois, you and your spouse (or civil union partner) jointly file a petition to adopt in the circuit court. Because a stepchild is a "related child" under the Adoption Act, the usual home investigation is skipped unless the judge orders one. The other parent's consent is often not needed: Illinois lets the court proceed without it when that parent is found "unfit," for example for deserting the child for more than three months before you file, or failing for 12 months to visit or communicate (750 ILCS 50/1(D), 50/8). In our experience, about 80% of the stepparent adoptions we've completed went forward without the other biological parent's consent. The father never signed, and the judge approved the adoption anyway.

Who Can Adopt a Stepchild in Illinois?

The Illinois Adoption Act (750 ILCS 50) sets the rules:

• You file jointly with your spouse or civil union partner. When a married person or civil union partner wants to adopt the other's child, "the adoption shall be by both spouses or civil union partners jointly" (750 ILCS 50/2(A)(a)). Your spouse joins the petition and keeps every parental right.
• Residence. Petitioners generally must have lived in Illinois for six months before filing, but that requirement doesn't apply to the adoption of a related child (750 ILCS 50/2(B)(a)), and a stepchild is a related child (750 ILCS 50/1).
• Any county. An adoption proceeding may be started in any county in Illinois (750 ILCS 50/4). Most families file where they live.

What if we're not married?

Illinois allows "a reputable person of legal age" to petition (750 ILCS 50/2(A)(a)), but the joint spouse-or-civil-union-partner path above is the standard stepparent route. If you're unmarried and not in a civil union, talk with an Illinois family law attorney before filing about whether your situation fits. Other states' rules are in our state guides.

Does the Other Parent Have to Consent?

Often, no. In Illinois, a parent's consent isn't required when the court finds, by clear and convincing evidence, that the parent is an "unfit person" (750 ILCS 50/8(a)(1)). The Act lists the grounds of unfitness in 750 ILCS 50/1(D). The ones stepfamilies rely on most are:

When a parent has stepped out of the child's life, these grounds fit the facts families describe to us every day. That's the real world in Illinois courtrooms: the father never signs, and the judge grants the adoption.

When the other parent agrees

He signs a consent to the adoption, acknowledged before a person authorized under the Act. Cooperative cases are usually the quickest.

When the father was never legally established

Illinois also has rules that can remove the need for consent from a man who isn't the legal father, such as a court finding that he isn't the biological father, or that he waived his rights under the Act (750 ILCS 50/8(a)(2)–(3)). Ask about these if your child was born outside marriage.

What If You Don't Know Where the Other Parent Is?

That doesn't stop the adoption. The Adoption Act builds publication right into the process. You file an affidavit that he can't be found after diligent inquiry, and the clerk publishes the notice in a newspaper in the county where the case is pending. The notice says he may be defaulted after a stated date, and within 10 days of the first publication the clerk also mails a copy to any address listed in your affidavit (750 ILCS 50/7(A)). Your names as petitioners are left out of the published notice.

Start a dated search log now: last known addresses, relatives, social media, phone numbers, public records. It's what your affidavit is built on.

Step 1: Gather Your Documents

Step 2: File the Joint Petition

You and your spouse file the petition in the circuit court. It names the other biological parent (and anyone else required) as a defendant and states either his consent or the grounds of unfitness you're alleging. In Cook County, adoptions are handled by the Circuit Court's County Division, which publishes a guide for self-represented litigants and a set of adoption forms; other counties have their own local forms, so ask your circuit clerk.

Step 3: Serve the Other Parent

All defendants are notified the same way as in other civil cases, except where publication applies (750 ILCS 50/7(A)). If he's served and doesn't answer or appear, he can be defaulted. If he can't be found, the clerk handles publication as described above.

Step 4: Investigation and Guardian ad Litem (Often Waived)

Two steps that apply in other adoptions are usually lighter for stepfamilies:

• Investigation. For a related child, the court-ordered investigation "shall not be made" unless the court, in its discretion, orders one (750 ILCS 50/6(D)).
• Guardian ad litem. Illinois normally appoints an attorney as guardian ad litem for the child, but in a related adoption where the child isn't a youth in care, the court has discretion to waive that appointment (750 ILCS 50/13(B)(a)).

Ask your judge or clerk early whether either will be required in your county; it affects cost and timing.

Step 5: The Final Hearing

If the other parent didn't consent, the court decides whether the grounds of unfitness are proven by clear and convincing evidence. If your child is 14 or older on the date of judgment, the child's written consent is required (750 ILCS 50/12). Then the judge enters the judgment of adoption. If the other parent appears and actively fights the case, that's a good time to talk with a local attorney.

Step 6: After the Adoption

You become your child's legal parent alongside your spouse. The other parent's duty to pay child support going forward ends (Child Welfare Information Gateway). Whether back support already owed can still be collected depends on Illinois law and your support order.

Ask the clerk how the adoption is reported for a new birth certificate, then update Social Security, school, medical and insurance records and your estate plan.

What Does It Cost in Illinois?

Item	What to expect
Document preparation (StepParent Adoption 360)	$349 for the first child, $99 for each additional child
Circuit court filing fees	Set by county; ask your circuit clerk
Service or publication	Depends on how the other parent is served
Guardian ad litem	Only if the court doesn't waive one
Investigation and fingerprint background check	Only if the court orders an investigation

See our stepparent adoption cost guide and the Illinois state guide.

How Long Does It Take?

Many uncontested adoptions finish within a few months. Your county's court calendar, how quickly the other parent is served, any publication period, and whether the court appoints a guardian ad litem or orders an investigation set the pace.

Frequently Asked Questions

Can I adopt my stepchild in Illinois if the father hasn't been around?

Yes. If he's found unfit, for example for deserting the child for more than 3 months before the case begins, failing to keep a reasonable degree of interest in the child, or failing for 12 months to visit or communicate, his consent isn't required (750 ILCS 50/1(D), 50/8). In our experience, about 80% of the stepparent adoptions we've completed went forward without the other parent's consent; the father never signed, and the judge approved the adoption anyway.

What if I don't know where the other parent lives?

You file an affidavit of diligent inquiry, and the clerk publishes the notice in a local newspaper and mails a copy to any known address (750 ILCS 50/7). If he doesn't respond, he can be defaulted.

Does my stepchild have to agree?

If your stepchild is 14 or older on the date of judgment, yes, in writing (750 ILCS 50/12).

Do I need a home study in Illinois?

Usually not. For a related child, which includes a stepchild, the investigation isn't made unless the court orders it (750 ILCS 50/6(D)).

Do we have to live in Illinois for six months first?

Not for a stepparent adoption. The six-month residence requirement doesn't apply to the adoption of a related child (750 ILCS 50/2(B)(a)).

Can a civil union partner adopt?

Yes. Illinois treats a civil union partner adopting the other partner's child the same way as a spouse: you file jointly (750 ILCS 50/2(A)(a)).

About the Author

Doug Brown, Founder. Doug Brown has helped families prepare stepparent and adult adoption paperwork since 2001: more than 34,000 families in all 50 states. StepParent Adoption 360 is a document-preparation service, not a law firm, and doesn't give legal advice.

Sources: Illinois Adoption Act, 750 ILCS 50/1, 50/2, 50/4, 50/6, 50/7, 50/8, 50/12 and 50/13 (Illinois General Assembly); Circuit Court of Cook County, "Adoption Court Procedures"; Child Welfare Information Gateway, "Stepparent Adoption" factsheet. Company figures (34,000+ families since 2001; about 80% of completed stepparent adoptions without the other parent's consent) are from our own records.