Pharmacy benefit management; requiring pharmacy benefit managers to maintain certain fiduciary duty. Effective date.

SB 161 requires pharmacy benefit managers (PBMs) operating in Oklahoma to act in the best interest of pharmacies by prohibiting specific practices. It bans PBMs from charging pharmacies fees for enrollment, credentialing, or claim processing, mandates equal reimbursement for comparable services (including PBM-owned pharmacies), and prevents retroactive claim denials except for fraud or audit errors. The bill also ensures pharmacies can inform patients about cost differences between using insurance versus paying directly. These rules directly affect all PBMs and retail pharmacies participating in Oklahoma's pharmacy networks.