Heyl Royster

Brad Antonacci

Chicago, IL

Joined Firm in 2002

Brad is not afraid of taking on the most complex Workers' Compensation claims and has been doing so for years. He is easily accessible to his clients, easy to get along with, and quickly responds to client requests.

  • Dedicated Workers' Compensation practice
  • Leading Lawyer by Law Bulletin Media
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Brad Antonacci

Attorney in Chicago, IL

Working out of the firm's Chicago office with extensive experience defending hundreds of employers before the Illinois Workers' Compensation Commission, Brad concentrates his practice solely on Workers' Compensation. Throughout his career, Brad Antonacci has arbitrated claims, argued reviews before the Commission, and appealed Illinois Workers' Compensation Commission decisions before the circuit court.

Beginning his career with Heyl Royster's Rockford office in 2002 after completing his J.D. at Northern Illinois University School of Law, Brad was promoted to partner in 2013. He is a frequent speaker and has authored articles on employment layoffs, temporary total disability benefits, and Workers' Compensation case law updates. He is a Workers' Compensation Lawyers' Association member and has been recognized by his peers for his legal accomplishments.

In his free time, he enjoys rooting for his favorite sports teams (including his children's teams), playing sports, and telling dad jokes.



J.D., Northern Illinois University School of Law

B.A., University of Illinois, Sociology

Licensure(s) and Admission(s)

State Courts of Illinois

United States District Court for the Northern District of Illinois

Professional Affiliations

Illinois Defense Counsel

Illinois State Bar Association 

Workers’ Compensation Lawyers’ Association


  • Ordoniz v. Dano Auto Body – Petitioner claimed he injured his low back and allegedly suffered a herniated disc while removing a car door from a vehicle. He amassed approximately $225,000 in outstanding medical bills for treatment in chiropractic care, physical therapy, medications, numerous spinal injections, radiofrequency ablation, and numerous radiological tests. The Workers' Compensation Commission relied on our IME and Utilization Review reports to find that the petitioner suffered a lumbar strain and denied approximately $225,000 in alleged outstanding medical bills as unreasonable, unnecessary, and causally unrelated to the work injury. The Commission awarded 3% person-as-a-whole.
  • Alanis v. Woodstock Christian Life Services – Petitioner injured her lower back while pushing a cart and slipping and falling on some water. She received medical treatment for approximately one month and was then released to return to work. She eventually began treating with a pain management physician who performed a series of lumbar spine injections and a radiofrequency ablation. When the pain management physician released the petitioner after one year of treatment, the petitioner had accumulated an extensive amount of outstanding medical bills which we denied. Relying on our IME physician, the Workers' Compensation Commission denied approximately $34,000 in alleged outstanding medical bills and awarded 6% person-as-a-whole for a lumbar strain.
  • Hieber v. Glass and Mirror Company – Petitioner suffered a compensable and accepted right shoulder injury. Following right shoulder surgery, the petitioner developed an infection in the right shoulder, resulting in revision surgery. Subsequent to the second surgery, the petitioner suffered from kidney failure and eventually required a kidney transplant. On behalf of the glass and mirror company, Heyl Royster presented evidence and an expert opinion that the renal failure was not related to the right shoulder surgeries and infection, that the petitioner had risk factors for developing renal failure, and that petitioner subsequently developed renal failure in the transplanted kidney. The arbitrator found the petitioner's renal failure to be causally connected to the right shoulder work injury and awarded all benefits related to the renal failure. On review, the Worker's Compensation Commission found no causal connection between the work injury and the petitioner's kidney condition, and the circuit court affirmed on appeal. The Commission's decision resulted in a reduction of the arbitrator's award of more than $300,000.



Can You Win In Illinois? Yes, You can! A Path to Success,” Heyl Royster's 34th Annual Claims Handling Seminar (2023)

Discussion of the McAllister Case and Pending Appeal; Case Law Update for 2020,” Heyl Royster WC Webinar Series

Going to the Bench: Bringing in an Expert Witness,” Heyl Royster's 32nd Annual Claims Handling Seminar (2017)

Functional Capacity Evaluations As Evidence of Disability In Workers’ Compensation Claims,” Heyl Royster's 31st Annual Claims Handling Seminar (2016)

Workers’ Compensation Case-Law Update,” Winnebago County Bar Association (2016)

All I Want for the Holidays is a Drone: Permitted Uses Today and What to Expect Tomorrow,” Heyl Royster Governmental Lunch & Learn Seminar, Rockford, IL (2015)

Vocational Rehabilitation – Respondent’s Perspective,” IICLE Advanced Workers’ Compensation Seminar (2014)

Case Law Update,” Heyl Royster 26th Annual Claims Handling Seminar (2011)

TTD Liability and Mass Layoffs," Heyl Royster 24th Annual Claims Handling Seminar (2009)


No Section 5(A) Immunity for General Contractor Operating Separately From Subsidiary-Subcontractor,” Below the Red Line - Heyl Royster Workers' Compensation Newsletter (2022)

Three Recent Appellate Court Jurisdictional Rulings Should Give Practitioners Pause When Filing Reviews,” Illinois Defense Counsel Quarterly (2018)

Corn Belt Energy Corp. v. Illinois Workers’ Compensation Commission: Is an AMA Rating Report Necessary and Should the Defense Obtain One?,” Illinois Defense Counsel Quarterly (2017)

"Loaning Employer Not Liable . . ., Personal Comfort Doctrine," Illinois Defense Counsel Quarterly (2008)


  • Leading Lawyer by Law Bulletin Media
  • Super Lawyer Rising Star by Super Lawyers®


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