N.J. Stat. § 43:13-22.49b
A separate account shall be established in the pension fund created pursuant to section 27 of P.L. 1954, c. 218 (C. 43:13-22.29) for each elected official of the city, and all contributions based on service as an elected official of the city shall be credited to this account, as distinguished from any other account that the elected official may have as a result of other public service covered by the retirement system. The elected official shall contribute at a rate equal to 5% of his official salary, which contribution shall be deducted from his salary at the time or times it is paid, and which shall be exclusive of any other contribution required of the member for Social Security, contributory death benefits or deductions for any other purpose.
An elected official of the city who is enrolled on the basis of other public service before, during, or after his service as such an elected official shall contribute for such other service at the rate of contribution required of other members of the system.
N.J.S. § 43:13-22.49b