Do I Need a DNA Test to Prove That I Am the Father in Illinois?

 Posted on August 28, 2025 in Family Law

Many fathers establish legal parentage without a lab test. If both parents agree, you can use simple paperwork or rely on rules tied to marriage. However, when there is a disagreement or confusion about who a child’s biological parents are, the court can step in to help work it out in the best interests of the child.

The right path depends on your relationship with the child’s mother, what the birth record shows, and whether anyone is challenging your paternity. A short meeting with an experienced Arlington Heights, IL paternity attorney can help you choose the option that protects your rights and keeps the process moving.

How Do You Establish Paternity in Illinois?

Illinois gives families a few clear routes to establish paternity. The quickest is a Voluntary Acknowledgment of Paternity (VAP), a form both parents sign and file with the state. Under 750 ILCS 46/305, the law treats that acknowledgment like a court judgment, giving the father legal rights and duties from day one.

Some families never need a form at all because the law presumes parentage based on marriage. According to 750 ILCS 46/204, if a child is born during a marriage, or within a set time after the marriage ends, the spouse is presumed to be the legal parent unless someone proves otherwise. 

If the parents are not married and are not both willing to sign a VAP, either parent can file a petition for a judge to establish parentage and then begin the process of allocating parental responsibilities, also known as custody.

When Is a DNA Test Needed To Establish Paternity in Illinois?

Genetic testing becomes important when there is a dispute over who the father is or when the court needs solid proof. A judge can order testing early in the case, and if a party asks for testing, the court generally allows it under 750 ILCS 46/401.

The test itself is a simple cheek swab taken from you and the child. Results that meet legal standards can confirm or exclude a biological relationship, and the court then uses that information to make a final decision. On the other hand, if both parents have already signed a valid acknowledgment, or the marriage presumption applies and no one challenges it, the case can move forward without DNA testing.

Can the Mother Force Me To Take a DNA Test in Illinois?

A private demand is not the same as a court order. Either you, the mother, or a public agency may ask the court to require testing. If the judge orders it, you must follow that order, and refusing can lead the court to decide parentage against you or impose other penalties. If you believe testing is unnecessary because you already signed a valid acknowledgment or you fall under a marriage presumption, your attorney can present those facts to the judge.

Contact an Arlington Heights, IL Paternity Attorney Today

Legal parentage affects parenting time, decision-making, and support. Therefore, getting it right matters. Our Arlington Heights, IL family law lawyers at A. Traub & Associates will review your situation, explain your options in plain language, and act quickly to protect your relationship with your child.

For over 15 years, we have helped Illinois families resolve paternity issues and related court orders. Our attorneys have been recognized by Super Lawyers. Our firm holds a 10.0 Avvo rating, the highest available, reflecting our commitment to quality work and client service. That peer recognition mirrors what we strive for in every case, which is strong, practical results for the people we serve. Call 847-749-4182 today for a consultation and a clear plan for moving forward.