N.J. Stat. § 43:13-22.49c
Notwithstanding any other law regarding the purchase of service credit, an elected official of the city may purchase credit for all previous service as such an elected official by paying into the pension fund 5% of the salaries he received in such prior periods, in which event he shall agree to make such purchase within 1 year after the effective date of this supplementary act or during the first year of service as an elected official in the city. If the request for the purchase is received beyond the 1-year period, interest shall be added to the amount of the arrearage obligation at an interest rate to be determined by the pension commission after consultation with the actuary. The purchase of service credit may be by lump sum or in regular installments over a maximum period of 10 years.
In the case of any elected official of the city coming under the provisions of this section, full pension credit for the period of service for which arrears are being paid by the member shall be given upon the payment of at least one-half of the total arrearage obligation and the completion of 1 year of service as an elected official of the city and the making of such arrears payments, except that in the case of retirement pursuant to section 17 of P.L. 1954, c. 218 (C. 43:13-22.19) and section 6 of P.L. 1972, c. 122 (C. 43:13-22.19a) and to this supplementary act, the total membership credit for such service shall be in direct proportion as the amount paid bears to the total amount of the arrearage obligation of the member.
No member shall receive credit for any service as an elected official of the city for which he has not contributed as required by this section.
N.J.S. § 43:13-22.49c