Nebraska Statutes: 23-1608
23-1608. County officers; audit required; cost. Each county board shall cause an examination and a complete and comprehensive annual audit to be made of the books, accounts, records, and affairs of all county officers in the county. The audits shall be conducted annually, except that the Auditor of Public Accounts may determine an audit of less frequency to be appropriate but not less than once in any three-year period. Each county board may contract with the Auditor of Public Accounts or select a licensed public accountant or certified public accountant or firm of such accountants to conduct the examination and audit and shall be responsible for the cost of the audit pursuant to the contract. The original copy of the audit shall be filed in the office of the Auditor of Public Accounts.