What Is the "Best Interest of the Child" Standard in Family Law?

 Posted on May 31, 2026 in Allocation of Parental Responsibilities

In family law cases involving questions about child custody, parents are strongly encouraged to work together to create a parenting plan that fits their situation. Judges are serious about making sure parents make a good faith effort to do this before asking for court intervention. Judges are allowed by Illinois law to require parents to go to mediation together for help creating a custody plan whenever necessary. What’s more, parents in Cook County must also take court-ordered parenting classes before a 2026 divorce or custody case can be finalized. 

However, parents cannot always cooperate well enough to make a parenting plan on their own. Cases involving abuse or neglect are usually also not good candidates for parental mediation. In situations like these, the court will step in to make custody decisions. 

Judges in Illinois always seek to find solutions that will give children as much stability as possible. But how could a judge, who doesn’t know a family, make such important decisions? What principles guide them? Illinois law addresses these questions, and our Hillside, IL child custody lawyer can explain what the answers might look like in your case. 

How Is Child Custody Decided in Illinois?

Legal parenting in Illinois is divided into two categories: Parental responsibilities, or decision-making powers, and parenting time, or visitation. Together, these are still commonly also referred to as custody. 

The "best interest of the child" standard is a legal principle that guides judges in making decisions about how parental responsibilities will be assigned, and how parenting time will be divided. Judges focus on protecting children’s health, safety and well-being. Of course, parents frequently disagree about how best to do this, and judges often have to rely on third parties to get accurate information. 

In strongly disputed custody cases, or in cases involving abuse or neglect, judges will often appoint a guardian ad litem or custody evaluator. This person’s job is to investigate a child’s life and make recommendations to the judge about what custody arrangement would be in a child’s best interests. 

The Factors Considered When Determining Child Custody Arrangements

When making decisions about child custody and parenting time, family court judges consider many factors to determine what would be in the best interest of the child. According to Illinois law, these factors may include:

• The child's wishes: Depending on their age and maturity level, a judge may take into account a child's preferences regarding custodial arrangements;

• The parents’ wishes: Each parent’s desires regarding how child-related decisions will be made and where children will live may be evaluated to determine whether compromises can be reached;

• Mental and physical health: The status of both parents may be evaluated to ensure they can provide a safe environment for their children;

• Parent-child relationships: The court will assess each parent's ability to foster a healthy relationship with their child and put their children’s needs ahead of their own;

• Children’s adjustment to their home and community: To maintain stability as much as possible, a judge may consider whether a custody arrangement will allow children to continue living in the same home and attending the same schools;

• Caregiving abilities: A judge will consider each parent's ability to meet their children's basic needs by providing food, shelter, clothing, education, healthcare, etc.;

• Historical caretaking role: A judge will look at how involved each parent has been in handling childcare duties during the two years prior to the initiation of a divorce or child custody case;

• Past decision-making responsibilities: In addition to considering parents’ involvement in caring for children, the court may also look at how they have worked together to make decisions in the past, or whether one parent has been primarily responsible for handling issues such as education or medical care;

• Co-parenting ability: A judge may assess each parent's willingness to cooperate with the other parent and make joint decisions regarding their children's upbringing;

• Practical issues: The distance between parents’ homes may be considered to determine how transportation arrangements will be handled;

• Domestic violence or abuse: Any history of abuse against children or other family members by a parent may be considered to ensure that children’s safety and well-being will be protected; and,

• Other factors: A judge may consider any other issues that they believe may affect children’s best interests while seeking to find solutions that will allow for stability and encourage positive parent/child relationships.

While these factors are written in Illinois law, using them to make custody decisions isn’t an exact science. Your attorney cannot predict exactly what the outcome of your case will be, but instead will work with you to make a well-constructed argument in favor of what you think is best for your family. 

Can I Get Sole Custody in Illinois? 

Your attorney will also work with you to help you understand what your options are and what certain judges tend to prefer. If you are asking for sole custody – whether this means exclusive parenting time, exclusive decision-making responsibilities, or both – you need to know that the law assumes this is not best for your child without strong evidence. 

This doesn’t mean it isn’t possible to get sole custody, but it does mean you will need to work closely with your attorney to create a well-supported argument using facts and evidence. Even still, sole custody is not the outcome in most custody cases.  

Contact Our Hillside Child Custody Attorney

Dealing with child custody matters can be very difficult. Hiring an experienced family law attorney who understands the "best interest of the child" standard is crucial to ensure that you can protect your rights as a parent and advocate for solutions that will allow for your family’s success.

If you are facing a child custody dispute in Illinois, the Law Office of Vincent C. Machroli, P.C. is here to help. Our Oak Park child custody lawyer has over 38 years of experience representing clients in family law cases. We understand how important it is to resolve these issues effectively. We will work to help you find solutions that will allow you to meet your children’s needs now and in the years to come. To schedule a no-charge legal consultation, contact the Law Office of Vincent C. Machroli, P.C. at 708-449-7404.