N.J. Stat. Ann. § 18A:30-3.6

3. Notwithstanding any law, rule or regulation to the contrary, a board of education, or an agency or instrumentality thereof, shall not pay supplemental compensation to any officer or employee for accumulated unused sick leave in an amount in excess of $15,000. Supplemental compensation shall be payable only at the time of retirement from a State-administered or locally-administered retirement system based on the leave credited on the date of retirement. This provision shall apply only to officers and employees who commence service with the board of education, or the agency or instrumentality thereof, on or after the effective date of P.L.2010, c.3. This section shall not be construed to affect the terms in any collective negotiations agreement with a relevant provision in force on that effective date.