; (2) in clause (iii), by striking (iii) the determination and inserting the following: (iii) (I) in any case in which the benefit referred to in subparagraph (A) consists of medical care (as defined in section 812(a)(2)), the determination of whether a trade or business is under common control with another trade or business shall be determined under regulations of the Secretary applying principles consistent and coextensive with the principles applied in determining whether employees of two or more trades or businesses are treated as employed by a single employer under section 4001(b), except that, for purposes of this paragraph, an interest of greater than 25 percent may not be required as the minimum interest necessary for common control, or (II) in any other case, the determination ; (3) by redesignating clauses (iv) and (v) as clauses (v) and (vi), respectively