105.660.  Definitions, retirement benefit changes. — The following words and phrases as used in sections 105.660 to 105.685, unless a different meaning is plainly required by the context, shall mean:

  (1)  "Actuarial valuation", a mathematical process which determines plan financial condition and plan benefit cost;

  (2)  "Actuary", an actuary:

  (a)  Who is a member of the American Academy of Actuaries or who is an enrolled actuary under the Employee Retirement Income Security Act of 1974; and

  (b)  Who is experienced in retirement plan financing;

  (3)  "Board", the governing board or decision-making body of a plan that is authorized by law to administer the plan;

  (4)  "Defined benefit plan", a plan providing a definite benefit formula for calculating retirement benefit amounts;

  (5)  "Defined contribution plan", a plan in which the contributions are made to an individual retirement account for each employee;

  (6)  "Funded ratio", the ratio of the actuarial value of assets over its actuarial accrued liability;

  (7)  "Lump sum benefit plan", payment within one taxable year of the entire balance to the participant from a plan;

  (8)  "Plan", any retirement system established by the state of Missouri or any political subdivision or instrumentality of the state for the purpose of providing plan benefits for elected or appointed public officials or employees of the state of Missouri or any political subdivision or instrumentality of the state;

  (9)  "Plan benefit", the benefit amount payable from a plan together with any supplemental payments from public funds;

  (10)  "Substantial proposed change", a proposed change in future plan benefits which would increase or decrease the total contribution percent by at least one-quarter of one percent of active employee payroll, or would increase or decrease a plan benefit by five percent or more, or would materially affect the actuarial soundness of the plan.  In testing for such one-quarter of one percent of payroll contribution increase, the proposed change in plan benefits shall be added to all actual changes in plan benefits since the last date that an actuarial valuation was prepared.  The closing or freezing of a current defined benefit plan is considered a substantial proposed change only for the purposes of sections 105.665, 105.670, 105.675, and 105.685.