Iowa Code § 524.203: Superintendent — vacancy.

If the office of the superintendent of banking is vacant or the superintendent is unable to serve, the chief of the bank bureau of the banking division shall be the acting superintendent until the governor appoints a new superintendent or acting superintendent. If the chief of the bank bureau is unable to serve, the chief examiner of the bank bureau of the banking division shall be the acting superintendent until the governor appoints a new superintendent or acting superintendent. If both the chief of the bank bureau and the chief examiner of the bank bureau are unable to serve, the chief of the finance bureau of the banking division shall be the acting superintendent until the governor appoints a new superintendent or acting superintendent.