(a) A health benefit plan that provides benefits for prescription drugs shall prorate any cost-sharing amount charged for a partial supply of a prescription drug if:
(1) the pharmacy or the enrollee’s prescribing physician or health care provider notifies the health benefit plan that:
(A) the quantity dispensed is to synchronize the dates that the pharmacy dispenses the enrollee’s prescription drugs; and
(B) the synchronization of the dates is in the best interest of the enrollee; and
(2) the enrollee agrees to the synchronization.
(b) The proration described by Subsection (a) must be based on the number of days’ supply of the drug actually dispensed.