contributions are invested as provided in paragraph (6), or (ii) be applied toward the purchase of a qualifying retirement bond. (5) Amount of contributions and payments (A) In general The amount specified in this paragraph with respect to any employee is— (i) 3 percent of the compensation of the employee, or (ii) such other percentage of compensation as is specified in regulations prescribed by the Secretary which is not less than 2 percent or more than 6 percent. (B) Authority to provide for periodic increases In the case of qualifying employees under an automatic IRA arrangement for 2 or more consecutive years, the Secretary may by regulation provide for periodic (not more frequent than annual) increases in the percentage of compensation an employee is deemed to have elected under subparagraph (A). The considerations the Secretary shall take into account in issuing any regulations under this subparagraph and subparagraph (A) shall include the potential effects on lower-income employees as well as on adequacy of savings. (C) Permitted additional procedures to limit contributions An employer— (i) shall have no responsibility for any calendar year for determining whether, or ensuring that, the contributions with respect to any employee do not exceed the deductible amount in effect for taxable years beginning in the calendar year under section 219(b)(5) (determined without regard to subparagraph (B) thereof), and (ii) shall not be treated as failing to satisfy the requirements of this section or any other provision of this title merely because the employer chooses to limit the contributions under this subsection on behalf of a qualifying employee for any calendar year in a manner reasonably designed to avoid exceeding such deductible amount. (6) Required investments (A) In general Amounts contributed under paragraph (4)(B)(i) shall be invested only in the class of assets or funds described in subparagraph (B) unless the employee elects a class of assets or funds described in subparagraph (C), (D), or (E). (B)