General rules.
General rules. In order to satisfy section 401(a)(9), except as otherwise provided in this section, distributions of the employee's entire interest under a defined benefit plan must be paid in the form of periodic annuity payments for the employee's life (or the joint lives of the employee and beneficiary) or over a period certain that does not exceed the maximum length of the period certain determined in accordance with A3 of this section. The interval between payments for the annuity must be uniform over the entire distribution period and must not exceed one year. Once payments have commenced over a period, the period may only be changed in accordance with A13 of this section. Life (or joint and survivor) annuity payments must satisfy the minimum distribution incidental benefit requirements of A2 of this section. Except as otherwise provided in this section (such as permitted increases described in A14 of this section), all payments (whether paid over an employee's life, joint lives, or a period certain) also must be nonincreasing.