(A) In general. If a cash or deferred arrangement is included in a plan (within the meaning of
§ 1.410(b)-7(b)) that is mandatorily disaggregated under the rules of
section 410(b) (as modified by this paragraph (b)(4)), the cash or deferred arrangement must be disaggregated in a consistent manner. For example, in the case of an employer that is treated as operating qualified separate lines of business under
section 414(r), if the eligible employees under a cash or deferred arrangement are in more than one qualified separate line of business, only those employees within each qualified separate line of business may be taken into account in determining whether each disaggregated portion of the plan complies with the requirements of
section 401(k), unless the employer is applying the special rule for employer-wide plans in
§ 1.414(r)-1(c)(2)(ii) with respect to the plan. Similarly, if a cash or deferred arrangement under which employees are permitted to participate before they have completed the minimum age and service requirements of
section 410(a)(1) applies
section 410(b)(4)(B) for determining whether the plan complies with
section 410(b)(1), then the arrangement must be treated as two separate arrangements, one comprising all eligible employees who have met the age and service requirements of
section 410(a)(1) and one comprising all eligible employees who have not met the age and service requirements under
section 410(a)(1), unless the plan is using the rule in
§ 1.401(k)-2(a)(1)(iii)(A).