N.J. Stat. Ann. § 43:13-22.49a

Notwithstanding the provisions of P.L.1954, c. 218 (C. 43:13-22.3 et seq.) or any other law, the governing body of a city, as defined by P.L.1954, c. 218 (C. 43:13-22.3 et seq.), may adopt an ordinance which makes elected officials of such city eligible for the special retirement benefits provided by this act. Upon the adoption of such an ordinance, all elected officials of the city shall become members of the retirement system of the city.