IL SB3509

Amends the Illinois Insurance Code to expand the definition of biomarker testing to include protein expression, whole exome, whole transcriptome sequencing, and known gene-drug interactions for medications being considered or already in use

Requires health insurers, nonprofit health service plans, and HMOs to update and publicly post medical policies and coverage guidelines within 90 days of the Act's effective date, with any future policy changes published 30 days before taking effect

Mandates that insurers provide specific written justification to providers, patients, or laboratories when denying claims for biomarker testing that is supported by FDA indications, CMS coverage determinations, or nationally recognized clinical practice guidelines

Establishes prior authorization timelines of 72 hours for non-urgent requests and 24 hours for urgent requests, with authorization requests permitted from ordering providers, laboratories, or enrollees

Authorizes the Department of Insurance to conduct periodic audits and reviews to ensure compliance with biomarker testing coverage requirements