Special rules relating to nondiscrimination requirements.—

A classification shall not be considered discriminatory within the meaning of paragraph (4) or section 410(b)(2)(A)(i) merely because it is limited to salaried or clerical employees.

A plan shall not be considered discriminatory within the meaning of paragraph (4) merely because the contributions or benefits of, or on behalf of, the employees under the plan bear a uniform relationship to the compensation (within the meaning of section 414(s)) of such employees.

A plan shall not be considered discriminatory within the meaning of paragraph (4) merely because the contributions or benefits of, or on behalf of, the employees under the plan favor highly compensated employees (as defined in section 414(q)) in the manner permitted under subsection (l).

(i) In general .— A defined benefit plan shall not be considered discriminatory within the meaning of paragraph (4) merely because the plan provides that the employer-derived accrued retirement benefit for any participant under the plan may not exceed the excess (if any) of— (I) the participant’s final pay with the employer, over (II) the employer-derived retirement benefit created under Federal law attributable to service by the participant with the employer.

For purposes of this clause, the employer-derived retirement benefit created under Federal law shall be treated as accruing ratably over 35 years.

(ii) Final pay .— For purposes of this subparagraph, the participant’s final pay is the compensation (as defined in section 414(q)(4)) paid to the participant by the employer for any year— (I) which ends during the 5-year period ending with the year in which the participant separated from service for the employer, and (II) for which the participant’s total compensation from the employer was highest.

For purposes of determining whether 2 or more plans of an employer satisfy the requirements of paragraph (4) when considered as a single plan—

(i) Contributions .— If the amount of contributions on behalf of the employees allowed as a deduction under section 404 for the taxable year with respect to such plans, taken together, bears a uniform relationship to the compensation (within the meaning of section 414(s)) of such employees, the plans shall not be considered discriminatory merely because the rights of employees to, or derived from, the employer contributions under the separate plans do not become nonforfeitable at the same rate.

(ii) Benefits .— If the employees’ rights to benefits under the separate plans do not become nonforfeitable at the same rate, but the levels of benefits provided by the separate plans satisfy the requirements of regulations prescribed by the Secretary to take account of the differences in such rates, the plans shall not be considered discriminatory merely because of the difference in such rates.

For purposes of testing for discrimination under paragraph (4)—

(i) the social security retirement age (as defined in section 415(b)(8)) shall be treated as a uniform retirement age, and

(ii) subsidized early retirement benefits and joint and survivor annuities shall not be treated as being unavailable to employees on the same terms merely because such benefits or annuities are based in whole or in part on an employee’s social security retirement age (as so defined).