; increased by (ii) the percentage by which the rebate period CPI–U (as defined in subparagraph (F)) for the calendar quarter exceeds the benchmark period CPI–U (as defined in subparagraph (E)). (D) Payment amount benchmark quarter The term payment amount benchmark quarter means the calendar quarter beginning January 1, 2016. (E) Benchmark period CPI–U The term benchmark period CPI–U means the consumer price index for all urban consumers (United States city average) for July 2015. (F) Rebate period CPI–U The term rebate period CPI–U means, with respect to a calendar quarter described in subparagraph (C), the greater of the benchmark period CPI–U and the consumer price index for all urban consumers (United States city average) for the first month of the calendar quarter that is two calendar quarters prior to such described calendar quarter. (4) Special treatment of certain drugs and exemption (A) Subsequently approved drugs Subject to subparagraph (B), in the case of a part B rebatable drug first approved by the Food and Drug Administration after July 1, 2015, clause (i) of paragraph (3)(C) shall be applied as if the term payment amount benchmark quarter were defined under paragraph (3)(D) as the third full calendar quarter after the day on which the drug was first marketed and clause (ii) of paragraph (3)(C) shall be applied as if the term benchmark period CPI–U were defined under paragraph (3)(E) as if the reference to July 2015 under such paragraph were a reference to the first month of the first full calendar quarter after the day on which the drug was first marketed . (B) Timeline for provision of rebates for new drugs In the case of a part B rebatable drug first approved by the Food and Drug Administration after July 1, 2015, clause (i) of paragraph (1)(B) shall be applied as if the reference to July 1, 2021 under such paragraph were a reference to the later of the 6th full calendar quarter after the day on which the drug was first marketed or July 1, 2021. (C) Exemption for shortages The Secretary may