Iowa Code § 105.15: Registry of licenses.

The name, location, license number, and date of issuance of the license of each person to whom a license has been issued shall be entered in a registry kept in the office of the department to be known as the plumbing, mechanical, HVAC-refrigeration, sheet metal, or hydronic registry. The registry may be electronic and shall be open to public inspection. However, the licensee’s home address, home telephone number, and other personal information as determined by rule shall be confidential.