; increased by (B) the percentage by which the rebate period CPI–U (as defined in subsection (g)(5)) for the applicable year exceeds the benchmark period CPI–U (as defined in subsection (g)(4)). (3) Special treatment of certain drugs and exemption (A) Subsequently approved drugs In the case of a part D rebatable drug first approved by the Food and Drug Administration after January 1, 2016, subparagraph (A) of paragraph (2) shall be applied as if the term payment amount benchmark year were defined under subsection (g)(3) as the first year beginning after the day on which the drug was first marketed and subparagraph (B) of paragraph (2) shall be applied as if the term benchmark period CPI–U were defined under subsection (g)(4) as if the reference to January 2016 under such subsection were a reference to January of the first year beginning after the date on which the drug was first marketed by any manufacturer . (B) Exemption for shortages The Secretary may reduce or waive the rebate under paragraph (1) with respect to a part D rebatable drug in the case of a shortage of such drug or other exigent circumstances, as determined by the Secretary. (C) Treatment of new formulations (i) In general In the case of a part D rebatable drug that is a line extension of a single source drug or an innovator multiple source drug that is an oral solid dosage form, the Secretary shall establish a formula for determining the amount specified in this subsection with respect to such part D rebatable drug and an applicable year with consideration of the single source drug or an innovator multiple source drug. (ii) Line extension defined In this subparagraph, the term line extension means, with respect to a part D rebatable drug, a new formulation of the drug (as determined by the Secretary), such as an extended release formulation, but does not include an abuse-deterrent formulation of the drug (as determined by the Secretary), regardless of whether such abuse-deterrent formulation is an extended release formulation. (D) Selected drugs