New Jersey Statutes Title 18A. Education 18A § 36B-21

a. (1) The school board of a sending district may adopt a resolution to restrict enrollment of its students in a choice district to a maximum of 10% of the number of students per grade level per year limited by any resolution adopted pursuant to this paragraph and 15% of the total number of students enrolled in the sending district, provided that the resolution shall be subject to approval by the commissioner upon a determination that the resolution is in the best interest of the district's students and that it will not adversely affect the district's programs, services, operations, or fiscal conditions, and that the resolution will not adversely affect or limit the diversity of the remainder of the student population in the district who do not participate in the choice program.

(2) Enrollment restriction percentages adopted by any resolution pursuant to paragraph (1) of this subsection shall not be compounded from year to year and shall be based upon the enrollment counts for the year preceding the sending district's initial year of participation in the choice program, except that in any year of the program in which there is an increase in enrollment, the percentage enrollment restriction may be applied to the increase and the result added to the preceding year's count of students eligible to attend a choice district. If there is a decrease in enrollment at any time during the duration of the program, the number of students eligible to attend a choice district shall be the number of students enrolled in the choice program in the initial year of the district's participation in the program, provided that a student attending a choice district school shall be entitled to remain enrolled in that school until graduation.

(3) The calculation of the enrollment of a sending district shall be based on the enrollment count as reported on the Application for State School Aid in October preceding the school year during which the restriction on enrollment shall be applicable.