; or (ii) for which payment is made separately under section 1833(i) or section 1833(t) and for which the payment amount is calculated based on the payment amount under this section. (3) Rebate amount (A) In general For purposes of paragraph (1)(B), the amount specified in this paragraph for a rebatable drug assigned to a billing and payment code for a rebate period is, subject to paragraph (4), the amount equal to the product of— (i) subject to subparagraph (B), the total number of units of the billing and payment code for such rebatable drug furnished during the rebate period; and (ii) the amount (if any) by which— (I) the amount determined under subsection (b)(4) for such rebatable drug during the rebate period; exceeds (II) the inflation-adjusted base payment amount determined under subparagraph (C) of this paragraph for such rebatable drug during the rebate period. (B) Excluded units For purposes of subparagraph (A)(i), the total number of units of the billing and payment code for rebatable drugs furnished during a rebate period shall not include units with respect to which the manufacturer provides a discount under the program under section 340B of the Public Health Service Act or a rebate under section 1927. (C) Determination of inflation-adjusted payment amount The inflation-adjusted payment amount determined under this subparagraph for a rebatable drug for a rebate period is— (i) the amount determined under subsection (b)(4) for such rebatable drug in the payment amount benchmark quarter (as defined in subparagraph (D))