Directory
Find a certified radon professional
742 radon testers and mitigation contractors so far, every one taken from an official state certification or licence list and checked twice. We are adding states one at a time.
Illinois
353 professionals. Illinois listings show the counties each licensee told IEMA they serve.
Browse →Pennsylvania
389 professionals. Pennsylvania listings show the county where the firm is based. Many firms work in neighboring counties too.
Browse →How we build and check listings
We only list businesses that appear on a current public list kept by a state radon program. For each one we record the state’s certification or licence number, the date of the list we used, and a second check against another official list from the same agency. We never add reviews, ratings or claims a state did not publish. Any business can ask us to remove or correct its listing.
Other states
Until we add your state, use the national certification boards, the NRPP pro search and NRSB find a pro, or your state radon program below. Some states license radon pros themselves; others accept NRPP or NRSB certification.
Free, no obligation
Get radon quotes from certified pros
Tell us what you need and we will try to connect you with up to three state-certified or licensed radon professionals who work in your area. It is free and there is no obligation.
We only share your request with radon professionals for this job. We do not sell your details to anyone else. Radon by ZIP may be paid by professionals for leads or featured placement.
Frequently asked questions
What is the difference between radon testing and radon mitigation?
Testing measures the radon level in a home. Mitigation lowers it, usually with a vent pipe and fan that pull soil gas from under the foundation. Many firms do both, but some states certify them separately.
Why does certification matter?
Several states, including Illinois and Pennsylvania, require anyone who tests or fixes radon for pay to hold a state licence or certification. Elsewhere, EPA suggests hiring a professional certified by a national program such as NRPP or NRSB.
Do businesses pay to be listed?
No. Every listing is free. Businesses can pay for a featured spot at the top of their county pages, and featured spots are always labelled.