(a) The board of trustees shall designate an actuary as its technical adviser.
(b) At least once every five years the actuary, on authorization of the board of trustees, shall:
(1) investigate the mortality, service, and compensation experience of the members and beneficiaries of the retirement system;
(2) on the basis of the investigation made under Subdivision (1), recommend to the board of trustees tables and rates that are required; and
(3) on the basis of tables and rates adopted by the board of trustees under § 825.105, evaluate the assets and liabilities of the retirement system.

(c) The board of trustees annually shall evaluate the performance of the actuary during the previous year. At least once every four years, the board shall redesignate its actuary after advertising for and reviewing proposals from providers of actuarial services.
(d) Each actuarial experience study must include a review of all actuarial assumptions in light of relevant experience, important trends, and economic projections. Interrelated actuarial assumptions shall be reviewed carefully to ensure that adjustments in one assumption are reflected appropriately in related assumptions.
(e) Each actuarial valuation must include a detailed analysis comparing experience factors to their actuarial assumptions. The analysis shall be developed and reported to identify significant variations in actual experience from what was assumed. A material variation should be the focus of an actuarial experience study.
(f) An actuarial audit shall be performed in conjunction with an actuarial experience study or at least once every five years. The audit must include:
(1) an analysis of the appropriateness of the actuarial assumptions;
(2) a review of the assumptions and methodology for compliance with the funding standards;
(3) verification of demographic data; and
(4) confirmation of the valuation results, including a determination of actuarial accrued liability, normal cost, expected employee contributions, and the effects of any recent legislation.