IL SB3740

Requires pharmacy benefit managers to pay the full amount that health insurers pay for prescription drugs to pharmacies, minus only the PBM's administrative costs.

Mandates PBMs update maximum allowable cost pricing at least every 7 calendar days and maintain processes to eliminate or modify drugs based on pricing changes and product availability.

Establishes a pharmacy appeal process allowing contracted pharmacies 14 calendar days to challenge reimbursement rates that are below their net acquisition cost, with PBMs required to respond within 14 days.

Prohibits PBMs from limiting pharmacists' ability to disclose whether a patient's cost-sharing exceeds the retail price and whether more affordable alternatives are available.

Requires PBMs to provide plan sponsors annual audit rights for contract compliance, including full disclosure of all rebates received from pharmaceutical manufacturers.