Neb. Rev. Stat. § 23-917: Neb. Rev. Stat. § 23-917

After the adoption of the county budget, no county shall be liable, either on any contract, implied contract or on any obligation arising by operation of law, for any merchandise, machinery, materials, supplies or other property delivered to or for any services rendered such county in pursuance of any contract entered into by or on behalf of such county in violation of the provisions of section 23-916 .