(a) The administrator shall use forfeitures that arise for any reason, including from termination of employment or death, to reduce employer contributions. Forfeitures may not be applied to increase the benefits of any member.
(b) The administrator shall determine the amount of any benefit that is determined on the basis of actuarial tables using assumptions approved by the commissioner. The amount of benefits is not subject to employer discretion.
(c) Employee contributions paid to, and retirement benefits paid from, the plan may not exceed the annual limits on contributions and benefits, respectively, allowed by 26 U.S.C. § 415. Notwithstanding any contrary provision of law, the administrator may modify a request by a member to make a contribution to a plan if the amount of the contribution would exceed the limits provided in 26 U.S.C. § 415 by using the following methods:

(1) if the law requires a lump sum payment for the purchase of service credit, the administrator may establish a periodic payment plan for the member to avoid a contribution in excess of the limits under 26 U.S.C. § 415(c) or (n);
(2) if a periodic payment plan under (1) of this subsection will not avoid a contribution in excess of the limits imposed by 26 U.S.C. § 415(c), the administrator may either reduce the member’s contribution to an amount within the limits of that section or refuse the member’s contribution.