Iowa Code Title XIV. Property [Chs. 555-594A] § 573.14. Retention of unpaid funds

1. The fund provided for in section 573.13 shall be retained by the public corporation for a period of thirty days after the completion and final acceptance of the improvement. If at the end of the thirty-day period claims are on file, the public corporation shall continue to retain from the unpaid funds a sum equal to double the total amount of all claims on file. The remaining balance of the unpaid fund, or if no claims are on file, the entire unpaid fund, shall be released and paid to the contractor.

2. The public corporation shall order payment of any amount due the contractor to be made in accordance with the terms of the contract. Except as provided in section 573.12 for progress payments, failure to make payment pursuant to this section, of any amount due the contractor, within forty days, unless a greater time period not to exceed fifty days is specified in the contract documents, after the work under the contract has been completed and if the work has been accepted and all required materials, certifications, and other documentations required to be submitted by the contractor and specified by the contract have been furnished the awarding public corporation by the contractor, shall cause interest to accrue on the amount unpaid to the benefit of the unpaid party. Interest shall accrue during the period commencing the thirty-first day following the completion of work and satisfaction of the other requirements of this subsection and ending on the date of payment. The rate of interest shall be determined by the period of time during which interest accrues, and shall be the same as the rate of interest that is in effect under section 12C.6, as of the day interest begins to accrue, for a deposit of public funds for a comparable period of time. However, for institutions governed pursuant to chapter 262, the rate of interest shall be determined by the period of time during which interest accrues, and shall be calculated as the prime rate plus one percent per year as of the day interest begins to accrue. This subsection does not abridge any of the rights set forth in section 573.16. Except as provided in sections 573.12 and 573.16, interest shall not accrue on funds retained by the public corporation to satisfy the provisions of this section regarding claims on file. This chapter does not apply if the public corporation has entered into a contract with the federal government or accepted a federal grant which is governed by federal law or rules that are contrary to the provisions of this chapter. For purposes of this subsection, “prime rate” means the prime rate charged by banks on short-term business loans, as determined by the board of governors of the federal reserve system and published in the federal reserve bulletin.