Iowa Code § 97A.12
The right of any person to a pension, annuity, or retirement allowance, to the return of contributions, the pension, annuity, or retirement allowance itself, any optional benefit or death benefit, any other right accrued or accruing to any person under this chapter, and the moneys in the retirement fund created under this chapter, are not subject to execution, garnishment, attachment, or any other process whatsoever, and are unassignable except for the purposes of enforcing child, spousal, or medical support obligations or marital property orders, or as otherwise specifically provided in this chapter. For the purposes of enforcing child, spousal, or medical support obligations, the garnishment or attachment of or the execution against compensation due a person under this chapter shall not exceed the amount specified in 15 U.S.C. § 1673(b).
Iowa Code § 97A.12