Medicare part A and Medicaid, and to establish the methodology and data collection requirements necessary to calculate the amount under paragraph (1)(A). (B) Methodology Any methodology established for the collection of data and calculation of the amount under paragraph (1)(A) shall take into account any legally mandated or voluntary discounts and rebates provided by the manufacturer of the applicable antimicrobial drug to the Federal health care programs that pay for such drug, on the condition that the Secretary may presume that discounts not described in subclauses (I) and (II) of subparagraph (C)(ii) are captured in the price determined under subparagraph (C)(i)(II). (C) Estimating annual net revenue (i) In general In determining the net revenue from sales of the applicable antimicrobial drug for beneficiaries or enrollees in Federal health care programs for the purpose of calculating the amount under paragraph (1)(A), the Secretary shall determine such net revenue amount by multiplying— (I) the total number of billing units of such antimicrobial drugs reported under the process described in subparagraph (D)(ii) for the applicable payment installment period