Multi-Source drug is a drug that is available from a brand name manufacturer and also from several generic manufacturers.
According to 42 USCS § 1396r-8(k)(7)(A)(i),the term "multiple source drug" means, with respect to a rebate period, a covered outpatient drug (not including any drug described in paragraph (5)) for which there [is] at least 1 other drug product which:
(I) is rated as therapeutically equivalent (under the Food and Drug Administration's most recent publication of "Approved Drug Products with Therapeutic Equivalence Evaluations");
(II) except as provided in subparagraph (B), is pharmaceutically equivalent and bioequivalent, as defined in subparagraph (C) and as determined by the Food and Drug Administration; and
(III) is sold or marketed in the State during the period.