If money is due to the permanent school fund, either for loans or deferred payments of the purchase price of land sold, the interest shall be made payable on the first day of January each year, and if the debtor fails to pay the interest within six months of the date it is due, the entire amount of both principal and interest shall become due, and the county auditor shall report the nonpayment to the school board, which may immediately commence action for the collection of the amount reported as due. This section is a part of a contract made by virtue of this chapter, whether expressed in the contract or not.
Iowa Code § 257B.10
83 Acts, ch 185, §13, 62 2011 Acts, ch 43, § 1