N.J. Stat. § 43:13-22.15d
Notwithstanding any of the provisions of the act to which this act is amendatory and supplementary limiting the time within which application for membership in the retirement system was required to be made and the rates and salaries upon which payments were to be computed, all present employees of the city who are otherwise eligible for membership may make application for and be admitted to membership in the retirement system upon declaration of intention in writing, made to the commission within 3 months of the effective date of this act, or within the time prescribed by the act hereby supplemented, whichever is later. To receive credit for all the time served as a permanent employee with the city prior to joining the retirement system, such employee shall pay into the fund a sum equal to an amount computed for the period of time at the salary scale and rate of contribution effective at the time application for purchase is made. Time payments and methods of deductions shall be the same as are presently in effect under the act hereby supplemented.
No person becoming a member of the retirement system pursuant to this section shall be eligible for retirement or disability retirement pension for a period of 5 years following the date of his admission to membership, except for disability arising out of and in the course of his employment.
N.J.S. § 43:13-22.15d