(a) A health benefit plan issuer that covers prescription drugs may not require an enrollee to make a payment for a prescription drug at the point of sale in an amount greater than the lesser of:
(1) the applicable copayment;
(2) the allowable claim amount for the prescription drug; or
(3) the amount an individual would pay for the drug if the individual purchased the drug without using a health benefit plan or any other source of drug benefits or discounts.
(b) A health benefit plan that covers prescription eye drops to treat a chronic eye disease or condition must allow the refill of prescription eye drops if the enrollee timely pays at the point of sale the maximum amount allowed by Subsection (a) and:
(1) the original prescription states that additional quantities of the eye drops are needed;
(2) the refill does not exceed the total quantity of dosage units authorized by the prescribing provider on the original prescription, including refills; and
(3) the refill is dispensed on or before the last day of the prescribed dosage period and:
(A) not earlier than the 21st day after the date a prescription for a 30-day supply of eye drops is dispensed;
(B) not earlier than the 42nd day after the date a prescription for a 60-day supply of eye drops is dispensed; or
(C) not earlier than the 63rd day after the date a prescription for a 90-day supply of eye drops is dispensed.