Chapter 04 — The Illinois file

Radon testing & mitigation in Illinois

Current IL IEMA credentials from the official Illinois roster. We group people by the city on that file. We do not invent neighborhoods. Source: IL IEMA.

Latest credential check August 29, 2026. Methodology Individual record dates may be earlier.

611current listings

474testing

137mitigation

Fig. 4 — 519 of 611 current listings are mapped. 91 records have no mappable in-state place. 1 record has an in-state place but no verified city or county coordinate. Each pin is a current listing at the Census city or county centroid on the file, approximate. Pins that share a place are spread so you can click them. Not street addresses.

§ 4.1

Cities with listings

A city appears only when at least one current listing serves it.

§ 4.3

How to verify a radon credential in Illinois

IL IEMA licenses radon work in Illinois and publishes a list we import monthly. Match the name and credential number on the official page before you hire.

Official IL IEMA verification page · All fifty states · reviewed September 8, 2026

§ 4.4

Questions about radon credentials in Illinois

Does Illinois license radon testers and mitigators?

IL IEMA licenses radon work in Illinois and publishes a current list with credential numbers. This site imports that list and re-checks it monthly. 611 current Illinois listings appear here as of August 29, 2026.

How do I verify a radon credential in Illinois?

Open the IL IEMA lookup at https://public.iema.state.il.us/Radon/Home/LicenseIndex, search the name, and match the credential number digit for digit. Status can change between our monthly check on August 29, 2026 and the day you hire. If the official page disagrees with this directory, the official page is right.

Is an NRPP or NRSB certification enough in Illinois?

Illinois issues its own radon credential through IL IEMA, so a national NRPP or NRSB certification is not a substitute for it. Every Illinois listing on this site shows the IL IEMA number, not a national one.