for a generic drug, $0;

for a preferred drug that is a multiple source drug (as defined in section 1396r–8(k)(7)(A)(i) of this title ), the dollar amount applied under this clause for such a drug for the preceding plan year, increased by the annual percentage increase in the consumer price index (all items; U.S. city average) as of September of such preceding year, or, if less, the copayment amount applicable to an individual under clause (iii); and

for a drug not described in either item (aa) or (bb), the dollar amount applied under this clause for such a drug for the preceding plan year, increased in the manner specified in item (bb), or, if less, the copayment amount applicable to an individual under clause (iii).