A. At least once in each two-year period, the actuary of the retirement system shall compute the annual rates of contributions payable by the employer on behalf of employees who are members. The rates shall be determined by an actuarial valuation of the retirement allowances and other benefits which will be payable on behalf of the employees who are members. The contributions shall be payable in lieu of contributions payable on behalf of other members in the system. The expense of making initial and subsequent valuations shall be assessed against and paid by the employer.
B. In the case of contributions payable by the employer on behalf of any local officer, the Commonwealth shall reimburse the employer on the basis on which the Commonwealth pays the salaries of the officer or shares or would share in the excess fees from the office. Payment shall be made from funds appropriated for this purpose.