Are Expert Witness Tax Returns and Financial Information Discoverable in Illinois?

Discovery regarding expert witnesses is governed by Illinois’s Supreme Court Rules, Rule 201. Ill. Comp. Stat. Ann. Sup. Ct. R. 201 (West 2017). This rule does not specifically note what each party must disclose regarding expert witnesses. Id. Looking to case law, the Supreme Court of Illinois has held that disclosing financial information of experts is allowed and can help show any potential bias or interest the expert may have in a case. Trower v. Jones, 520 N.E.2d 297 (Ill. 1988). However, the court has the authority to limit the extent of examination into the expert’s financial information. Sears v. Rutishauser, 466 N.E.2d 210 (Ill. 1984).