the date of the implementation of the payment system under paragraph (1)(A). (iii) Transitional home infusion drug defined For purposes of this paragraph, the term transitional home infusion drug has the meaning given to the term home infusion drug under section 1861(iii)(3)(C)), except that clause (ii) of such section shall not apply if a drug described in such clause is identified in clauses (i), (ii), (iii) or (iv) of subparagraph (C) as of the date of the enactment of this paragraph. (B) Payment methodology For purposes of this paragraph, the Secretary shall establish a payment methodology, with respect to items and services described in subparagraph (A)(i). Under such payment methodology the Secretary shall— (i) create the three payment categories described in clauses (i), (ii), and (iii) of subparagraph (C)