N.J. Stat. Ann. § 43:10-18.22

All funds created under this act and all pensions granted under this act shall be exempt from any State, county, or municipal tax, levy and sale, garnishment or attachment, or any other process and shall be unassignable, except that pension payments to be made to a pensioner may be assigned in writing by the pensioner but only for the payment of premiums for group plan for hospital service or for hospital, medical and surgical insurance or 1 or more of them.