New Jersey Statutes Title 18A. Education 18A § 16-1.1b

a. A vacant teaching position shall not be filled in any school year by one or more individuals employed as substitute teachers and holding a certificate of eligibility or a certificate of eligibility with advanced standing issued by the State Board of Examiners and working in an area authorized by their credentials for a total amount of time exceeding 60 school days. The executive county superintendent of schools may grant an extension upon written application from the school district demonstrating the district's inability to hire an appropriately certified teacher for the vacant position within the original 60-day time limit.

b. In the event that one individual employed pursuant to subsection a. of this section is employed in the same position for more than 60 days, he shall be compensated by the school district on a pro-rata basis consistent with the salary provided to a teacher with similar credentials in the employing district.