Iowa Code § 43.11: Filing of nomination papers.

Nomination papers in behalf of a candidate shall be filed:

1. For an elective county office, in the office of the county commissioner not earlier than ninety-two days nor later than 5:00 p.m. on the seventy-fourth day before the day fixed for holding the primary election.

2. For United States senator, for an elective state office, for representative in Congress, and for member of the general assembly, in the office of the state commissioner not earlier than ninety-nine days nor later than 5:00 p.m. on the eighty-first day before the day fixed for holding the primary election.