Neb. Rev. Stat. § 79-910.01

(1) Each person employed by a public school who is a school employee and who is qualified to participate in the retirement system shall participate in the retirement system. (2) Public schools shall ensure that all school employees who qualify for participation pursuant to this section shall begin annual participation on July 1 of each plan year or upon such person's date of hire, if later than July 1, and that all required deposits are made on behalf of such employees.