Iowa Code § 280.31

The board of directors of a school district, the superintendent or chief administering officer of a school or school district, and the authorities in charge of each accredited nonpublic school shall not adopt, enforce, or implement a policy that requires its employees, students, or members of the public to wear a facial covering for any purpose while on the school district’s or accredited nonpublic school’s property unless the facial covering is necessary for a specific extracurricular or instructional purpose, or is required by section 280.10 or 280.11 or any other provision of law.