1.410(b)-8—Additional rules.
(a) Testing methods—
(1) In general.
A plan must satisfy section 410(b) for a plan year using one of the testing options in paragraphs (a)(2) through (a)(4) of this section. Whichever testing option is used for the plan year must also be used for purposes of applying section 401(a)(4) to the plan for the plan year. The annual testing option in paragraph (a)(4) of this section must be used in applying section 410(b) to a section 401(k) plan or a section 401(m) plan, and in applying the average benefit percentage test of § 1.410(b)-5. For purposes of this paragraph (a), the plan provisions and other relevant facts as of the last day of the plan year regarding which employees benefit under the plan for the plan year are applied to the employees taken into account under the testing option used for the plan year. For this purpose, amendments retroactively correcting a plan in accordance with § 1.401(a)(4)-1 1(g) are taken into account as plan provisions in effect as of the last day of the plan year.
(2) Daily testing option.
A plan satisfies section 410(b) for a plan year if it satisfies § 1.410(b)-2 on each day of the plan year, taking into account only those employees (or former employees) who are employees (or former employees) on that day.
(3) Quarterly testing option.
A plan is deemed to satisfy section 410(b) for a plan year if the plan satisfies § 1.410(b)-2 on at least one day in each quarter of the plan year, taking into account for each of those days only those employees (or former employees) who are employees (or former employees) on that day. The preceding sentence does not apply if the plan's eligibility rules or benefit formula operate to cause the four quarterly testing days selected by the employer not to be reasonably representative of the coverage of the plan over the entire plan year.
(4) Annual testing option.
A plan satisfies section 410(b) for a plan year if it satisfies § 1.410(b)-2 as of the last day of the plan year, taking into account all employees (or former employees) who were employees (or former employees) on any day during the plan year.
Code of Federal Regulations
(b) Family member aggregation rule.
For purposes of section 410(b), and in accordance with section 414(q)(6), a highly compensated employee who is a 5-percent owner or one of the ten most highly compensated employees and any family member (or members) of such a highly compensated employee who is also an employee of the employer are to be treated as a single highly compensated employee. If any member of that group is benefiting under a plan, the deemed single employee is treated as benefiting under the plan. If no member of that group is benefiting under a plan, the deemed single employee is treated as not benefiting under the plan.