Requires health insurers and pharmacy benefit managers to reduce an enrollee's defined cost sharing for a prescription drug by a price amount equal to at least 100 per cent of all rebates received, or to be received, in connection with the dispensing or administration of the prescription drug. Requires a pharmacy benefit manager to submit a certification to the Insurance Commissioner by January 1 of each calendar year certifying compliance with the cost sharing requirements. Establishes protections for the publishing of certain confidential or proprietary information by health insurers or pharmacy benefit managers.