In general
In order to encourage beneficiaries to use drugs (in this subsection referred to as “preferred drugs”) identified by the State as the most (or more) cost effective prescription drugs within a class of drugs (as defined by the State), with respect to one or more groups of beneficiaries specified by the State, subject to paragraph (2), the State may—
(A)#
provide cost sharing (instead of the level of cost sharing otherwise permitted under section 1396 o of this title, but subject to paragraphs (2) and (3)) with respect to drugs that are not preferred drugs within a class; and
(B)#
waive or reduce the cost sharing otherwise applicable for preferred drugs within such class and shall not apply any such cost sharing for such preferred drugs for individuals for whom cost sharing may not be imposed under subsection (a) due to the application of subsection (b)(3)(B).