Iowa Code § 622.67: Deposit — effect.

The court, for good cause shown, upon deposit with the clerk of the court of sufficient money to pay the fee and mileage of a witness, may order the clerk to issue a subpoena requiring the attendance of the witness from a greater distance within the state. The subpoena shall show that it is issued under this section. If the party requesting the subpoena is a county or the state, the court may order the issuance of the subpoena without the deposit of the fee and mileage.