Sec. 4.03. MEMBER CONTRIBUTIONS. (a) Subject to Subsection (a-1) of this section and except as provided by Section 4.025 of this article, each Group A member of the combined pension plan shall have 13.5 percent of base pay deducted from the member's wages on a biweekly basis, and the contributions shall be promptly remitted to the fund by the city.

(a-1) If a Group A member is assigned, for any period, to a job-sharing program or any similar work schedule that is considered by the member's department to be less than a full-time work schedule, the member's contributions are determined by multiplying the applicable contribution rate by a fraction, the numerator of which is the number of hours the member actually worked during the period and the denominator of which is the number of hours the member would have worked during the period if the member had been working a full-time work schedule.

(b) Each member shall contribute to the fund under the applicable terms of this article until the member leaves active service with either department. If a member leaves active service with a department, the member shall cease making contributions.

(c) Each Group B member shall authorize the city to deduct from the member's salary a percentage of the member's computation pay. The authorization shall be in writing and filed with the executive director.

(d) Subject to Subsection (d-1) of this section and except as provided by Section 4.025 of this article, for pay periods starting on or after September 1, 2017, each Group B member shall have 13.5 percent of the member's computation pay deducted from the member's wages on a biweekly basis and the contributions shall be promptly remitted to the fund by the city.

(d-1) If a Group B member is assigned, for any period, to a job-sharing program or any similar work schedule that is considered by the member's department to be less than a full-time work schedule, the member's contributions are determined by multiplying the applicable contribution rate by a fraction, the numerator of which is the number of hours the member actually worked during the period and the denominator of which is the number of hours the member would have worked during the period if the member had been working a full-time work schedule.

(d-2) For purposes of Subsection (d) of this section, "computation pay" includes computation pay paid to a Group B member during any period the member is receiving workers' compensation.

(e) The city shall determine the frequency of deductions for member contributions, as long as there is at least one deduction each month.

(f) Each Group B member shall contribute to the fund beginning on the effective date of the member's Group B membership.

(g) The percentage of base pay contributed by Group A members or computation pay contributed by Group B members may not be altered except by an adjustment under Section 4.025 of this article.

(h) The only purposes for which member contributions to the fund and the investment income derived from member contributions may be applied are:

(1) to the payment of benefits prescribed by this article;

(2) to the payment of such administrative and professional service costs of the pension system as are provided for under Section 4.01 of this article or as may be within the discretion of the board to incur; and

(3) to invest any surplus in accordance with Section 4.07 of this article.

(i) Member contributions under this article or any payments a member is entitled to make under this article to receive additional pension service may be picked up by the city under the terms of an appropriate resolution of the city council.