N.J. Stat. Ann. § 18A:6-64

Except as provided in section 13 of this act, a school district which is a member of a commission may withdraw from membership by adopting a resolution setting forth its intention to withdraw and the reason or reasons for the withdrawal, and filing with the county superintendent or superintendents, as the case may be, and secretary of the board of directors a certified copy of such resolution. The withdrawal shall be effective at the conclusion of the third full school year after the filing of such resolution with the secretary of the board of directors.