A health care insurer that offers, issues, delivers, or renews a health care insurance plan in the individual or group market in the state that provides coverage for prescription drugs for which cost sharing, deductibles, or copayment obligations are determined by unique categories or specialty tiers may impose cost sharing, deductibles, or copayment obligations for a unique category or specialty tier prescription drug that exceed the dollar amount of cost sharing, deductibles, or copayment obligations, as applicable, for a nonpreferred brand drug or the drug's equivalent, but only if the insurer notifies the insured of the cost sharing, deductible, or copayment terms applicable to unique categories or specialty tiers at least 90 days before the terms apply.