Sec. 9. (a) At the time of contracting, an insurer shall only offer to plan sponsors the following plans:
(1) A plan that applies one hundred percent (100%) of the rebates to reduce premiums for all covered individuals equally.
(2) A plan that calculates defined cost sharing for covered individuals of the plan sponsor at the point of sale based on a price that is reduced by an amount equal to at least eighty-five percent (85%) of all of the rebates received or estimated to be received by the insurer concerning the dispensing or administration of the prescription drug.
(b) A plan sponsor may choose one (1) of the plans offered under subsection (a).