N.J. Stat. § 40:20-20.5
In the event of a favorable vote on a proposition submitted pursuant to the provisions of section 6 of this amendatory and supplementary act, the first election of members of the board of chosen freeholders under that adopted proposition shall take place at the next general election immediately following that adoption.
In November of the first general election following the adoption of the proposition, the terms of all incumbent members of the board of chosen freeholders shall be deemed terminated at noon on the first Monday following the election of the new board of chosen freeholders. On that date, the newly elected freeholders shall take office and the new board shall organize itself accordingly, but their terms of office shall expire as if they had taken office on January 1 in the year following their election and in accordance with the following terms:
The length of the terms specified in subsections a. through d. of this section shall be determined by a drawing to be conducted by the county clerk 60 days prior to the first general election.
In all elections after the first election, all members shall be elected for four year terms beginning on January 1 in the year following their election.
Nothing in this section shall be construed to prevent an incumbent freeholder from becoming a candidate for the new board, even if his present term on the board has not yet expired.
N.J.S. § 40:20-20.5