average sales price increase described in subparagraph (A)(ii) of such paragraph for such rebatable drug and rebate period. (iii) The rebate amount specified under such paragraph for such rebatable drug and rebate period. (B) Manufacturer rebate (i) In general Subject to clause (ii), for each rebate period beginning on or after January 1, 2021, the manufacturer of a rebatable drug shall, for such drug, not later than 30 days after the date of receipt from the Secretary of the information and rebate amount pursuant to subparagraph (A) for such rebate period, provide to the Secretary a rebate that is equal to the amount specified in paragraph (3) for such drug for such rebate period. (ii) Exemption for shortages The Secretary may reduce or waive the rebate under this subparagraph with respect to a rebatable drug that is listed on the drug shortage list maintained by the Food and Drug Administration pursuant to section 506E of the Federal Food, Drug, and Cosmetic Act. (C) Request for reconsideration The Secretary shall establish procedures under which a manufacturer of a rebatable drug may request a reconsideration by the Secretary of the rebate amount specified under paragraph (3) for such rebatable drug and rebate period, as reported to the manufacturer pursuant to subparagraph (A)(iii). (2) Rebate period and rebatable drug defined In this subsection: (A) Rebate period The term rebate period means a calendar quarter beginning on or after January 1, 2021. (B) Rebatable drug The term rebatable drug means a single source drug or biological (other than a biosimilar biological product)— (i) described in section 1842(o)(1)(C) for which the payment amount is provided under this section