than 1 State— (i) if each such State maintains or facilitates a qualifying State-facilitated automatic IRA program, the employer participation rules of each such program (and of subparagraph (A)) apply, respectively, to employees employed in such State, and (ii) if one or more of such States, but not all, maintain or facilitate a qualifying State-facilitated automatic IRA program— (I) the employer participation rules of each such program (and of subparagraph (A)) apply, respectively, to employees employed in such State, and (II) the employer is a covered employer for purposes of this section with respect to qualifying employees employed in States which do not maintain or facilitate such a program (unless otherwise excluded under paragraph (3)(A)), unless the employer makes an irrevocable election to be treated as a covered employer for purposes of this section with respect to all qualifying employees in all States. (6) Aggregation rule All persons treated as a single employer under subsection (a) or (b) of section 52 or subsection (m) or (o) of section 414 shall be treated as a single employer. (c) Qualifying employee For purposes of this section— (1) In general The term qualifying employee means any employee of the employer other than— (A) an excluded employee, and (B) an employee who participates in (or is eligible to, and has elected not to, participate in) a qualifying State-facilitated automatic IRA. (2) Plan sponsor’s employees If— (A) an employer maintains one or more qualifying plans or arrangements described in section 219(g)(5), (B) the employees of any subsidiary, division, or other major business unit of the employer are generally not eligible to participate in any such qualifying plan or arrangement, and (C) the number of employees of the employer described in subparagraph (B) for a calendar year is— (i) at least 50, and (ii) at least 10 percent of the employees of the employer (other than excludable employees), then, for purposes of this section, the employer shall be treated as a covered employer