Sec. 8A. CITY CONTRIBUTIONS. (a) The city shall make contributions to the pension system for deposit into the pension fund as provided by this section and Section 8B, 8C, 8E, or 8F of this Act, as applicable. The city shall contribute:

(1) beginning with the year 2017 effective date and ending with the fiscal year ending June 30, 2018, an amount equal to the sum of:

(A) the city contribution rate, as determined in the initial risk sharing valuation study conducted under Section 8C of this Act, multiplied by the pensionable payroll for the fiscal year; and

(B) the city contribution amount for the fiscal year; and

(2) for each fiscal year after the fiscal year ending June 30, 2018, an amount equal to the sum of:

(A) the city contribution rate, as determined in a subsequent risk sharing valuation study conducted under Section 8B of this Act and adjusted under Section 8E or 8F of this Act, as applicable, multiplied by the pensionable payroll for the applicable fiscal year; and

(B) except as provided by Subsection (e) of this section, the city contribution amount for the applicable fiscal year.

(b) Except by written agreement between the city and the pension board under Section 3(n) of this Act providing for an earlier contribution date, at least biweekly, the city shall make the contributions required by Subsection (a) of this section by depositing with the pension system an amount equal to the sum of:

(1) the city contribution rate multiplied by the pensionable payroll for the biweekly period; and

(2) the city contribution amount for the applicable fiscal year divided by 26.

(c) With respect to each fiscal year:

(1) the first contribution by the city under this section for the fiscal year shall be made not later than the date payment is made to employees for their first full biweekly pay period beginning on or after the first day of the fiscal year; and

(2) the final contribution by the city under this section for the fiscal year shall be made not later than the date payment is made to employees for the final biweekly pay period of the fiscal year.

(d) In addition to the amounts required under this section, the city may at any time contribute additional amounts to the pension system for deposit in the pension fund by entering into a written agreement with the pension board in accordance with Section 3(n) of this Act.

(e) If, in any given fiscal year, the funded ratio is greater than or equal to 100 percent, the city contribution under this section may no longer include the city contribution amount.

(f) Contributions shall be made under this section by the city to the pension system in order to be credited against any amortization schedule of payments due to the pension system under this Act.

(g) Subsection (f) of this section does not affect the exclusion of contribution amounts under Subsection (e) of this section or changes to an amortization schedule of a liability layer under Section 8B(a)(7)(F), 8C(i)-(j), or 8E(c)(3)-(4) of this Act.

(h) Notwithstanding any other law and except for the pension obligation bond assumed under Section 8C(d)(2) of this Act, the city may not issue a pension obligation bond to fund the city contribution rate under Subsection (a)(1)(A) or (a)(2)(A) of this section or the city contribution amount under Subsection (a)(1)(B) or (a)(2)(B) of this section.