Neb. Rev. Stat. § 79-102

School districts in this state are classified as follows: (1) Class I includes any school district embracing territory having a population of fewer than one thousand five hundred inhabitants that maintains both elementary and high school grades under the direction of a single school board; (2) Class II includes any school district embracing territory having a population of one thousand five hundred or more but fewer than five thousand inhabitants that maintains both elementary and high school grades under the direction of a single school board; (3) Class III includes any school district embracing territory having a population of five thousand or more but fewer than two hundred thousand inhabitants that maintains both elementary and high school grades under the direction of a single school board; (4) Class IV includes any school district embracing territory having a population of two hundred thousand or more inhabitants with a city of the primary class within the territory of the district that maintains both elementary and high school grades under the direction of a single school board; and (5) Class V includes any school district whose employees participate in a retirement system established pursuant to the Class V School Employees Retirement Act and which embraces territory having a city of the metropolitan class within the territory of the district that maintains both elementary grades and high school grades under the direction of a single school board and any school district with territory in a city of the metropolitan class created pursuant to the Learning Community Reorganization Act and designated as a Class V school district in the reorganization plan.