N.J. Stat. Ann. § 18A:66-14

Any person employed temporarily as a teacher whose temporary employment resulted, without interruption, in permanent employment, and any person who was employed as a substitute immediately prior to permanent employment may purchase credit for the temporary or substitute service. The purchase shall be made in the same manner and be subject to the same terms and conditions provided for the purchase of previous membership service by N.J.S.18A:66-9.