Neb. Rev. Stat. § 23-404: Neb. Rev. Stat. § 23-404

In any county having a population of four hundred thousand inhabitants or more as determined by the most recent federal decennial census, there shall be a civil service commission which shall be formed as provided in the County Civil Service Commission Act. A county shall comply with this section within six months after a determination that the population has reached four hundred thousand inhabitants or more as determined by the most recent federal decennial census.