Iowa Code § 523A.605: Allocation of growth or interest.

If a purchase agreement funded by insurance proceeds under section 523A.401 or by annuity proceeds under section 523A.402 includes nonguaranteed merchandise or services, the purchaser, beneficiary, or the beneficiary’s estate shall receive a credit for, and the benefit of, any growth in death benefits that is at least equal to the percentage of the total price under the purchase agreement that is attributable to the nonguaranteed merchandise or services.