N.J. Stat. § 43:10-18.55
The members and certain conditions of membership in the retirement system created by this act shall be as follows:
Such persons shall not be given credit for pension purposes hereunder for any prior service; provided, however, that where any such employee has had prior service as an employee in any State, county or municipal position, such employees shall be given credit for pension purposes hereunder for such prior service upon written application therefor to the pension commission within 1 year after becoming a member of this retirement system and upon payment into the retirement system herein provided, for a period of time equal to the length of prior service for which credit is allowed, of a sum of money equal in amount to 6% of salary, said 6% of salary being based upon the salary received by such employee at the time of the making of said application. Said sum of money may be paid in one lump sum or by semimonthly deductions from salary, whichever method the applicant may elect, together with the regular deductions provided by this act, until completed; provided, however, that such prior service shall be credited only as paid for. All payments aforesaid by the employee shall be made together with interest thereon at a rate to be determined by the pension commission.
County detectives in counties of the first, second, third and fifth classes (article 2 of chapter 10 of Title 43 of the Revised Statutes);
Probation officers of counties of over 83,000 inhabitants (article 5 of chapter 10 of Title 43 of the Revised Statutes);
Sheriff's employees in counties of the first and second classes (article 6 of chapter 10 of Title 43 of the Revised Statutes);
County superintendents of weights and measures and assistant county superintendent of weights and measures ( "An act providing for the retirement of persons employed in the department of weights and measures of any county in this State, and providing a pension for such persons so retired," filed June 21, 1938 (P.L. 1938, c. 397));
County park police in counties of more than 200,000 population (sections 40:37-157 to 40:37-174, inclusive, of the Revised Statutes);
Court interpreters in counties of the second class (article 9 of chapter 10 of Title 43, of the Revised Statutes); shall on January 1, 1949, automatically become members of the county employees' retirement system provided for by this act, and all such employees shall be deemed to agree and consent to the transfer of such membership unless they, or any one or more of them shall, before January 1, 1949, by written notice to the pension commission of their respective retirement systems operating in such county, elect to withdraw therefrom their contributions theretofore made, without interest. Any such member electing to withdraw from such membership shall thereafter be ineligible for membership in any retirement system of such county, or for any pension payable, in whole or in part, by funds of such county under the provisions of any statute of this State except sections 43:4-1 to 43:4-5, inclusive, of the Revised Statutes.
All such employees who become members of the county employees' retirement system provided for by this act and other county employees mentioned in paragraph (b) who become members of the said county employees' retirement system and who have held elective office in the county government, shall be given credit for pension purposes hereunder for all services, including services performed in any elective office, rendered to the county prior to January 1, 1949; provided, however, that where any such employee had theretofore agreed, under the provisions of article 1 of chapter 10 of Title 43 of the Revised Statutes, to pay for any part or all of such service rendered to the county prior to January 1, 1949, the transfer or approval of such employee's membership into this system shall include the transfer to this system of all conditions and obligations of such prior agreement made by such employee and such employee shall be deemed to agree and consent to the transfer to this system of such conditions and obligations until the conditions of such agreement have been fully complied with. Employees mentioned in paragraph (b) who have held elective office in the county government prior to January 1, 1949, who were not members of the aforesaid systems defined in paragraph (c) herein, shall be given credit for pension purposes for all services including services performed in any elective office, rendered to the county prior to January 1, 1949, upon such employee agreeing and consenting in writing to pay for any part or all of such services rendered to the county prior to January 1, 1949 at the rate of 3% of the salary received for a period of time equal to the length of the prior elective service for which credit is allowed, plus interest thereon at a rate to be determined by the pension commission.
Except as otherwise provided by section 8 of this act, where any such employee's membership shall be transferred to this retirement system on January 1, 1949, such employee shall be given credit for pension purposes hereunder for any prior service or services rendered as an employee of the State and of any municipalities or other political subdivisions of the State, upon application therefor to the pension commission within 1 year after the transfer of such membership, and upon payment into the retirement system herein provided, for a period of time equal to the length of prior service for which credit is allowed, of a sum of money equal in amount to 3% of salary, said 3% of salary being based upon the salary received by such employee at the time of the making of said application. Said sum of money may be paid in one lump sum or by semimonthly deductions from salary, whichever method the applicant may elect, together with the regular deductions provided by this act, until completed; provided, however, that such prior service shall be credited only as paid for. All payments aforesaid by the employee shall be made together with interest thereon at a rate to be determined by the pension commission.
N.J.S. § 43:10-18.55