Iowa Code § 53.32: Ballot of deceased voter.

When it shall be made to appear by due proof to the precinct election officials that any elector, who has so marked and forwarded a ballot, has died before the envelope marked with the affidavit is opened, then the ballot of such deceased voter shall be endorsed, “Rejected because voter is dead”, and be returned to the commissioner. The casting of the ballot of a deceased voter shall not invalidate the election.