Application of nondiscrimination rules

An applicable employer plan shall be treated as failing to meet the nondiscrimination requirements under section 401(a)(4) with respect to benefits, rights, and features unless the plan allows all eligible participants to make the same election with respect to the additional elective deferrals under this subsection.

For purposes of subparagraph (A), all plans maintained by employers who are treated as a single employer under subsection (b), (c), (m), or ( o ) of section 414 shall be treated as 1 plan, except that a plan described in clause (i) of section 410(b)(6)(C) shall not be treated as a plan of the employer until the expiration of the transition period with respect to such plan (as determined under clause (ii) of such section).