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How to Find a Certified Radon Mitigation Contractor

Updated November 1, 2026 · General information, not medical advice

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Why hire a certified pro

EPA recommends a qualified radon mitigation contractor because lowering high radon levels requires specific technical knowledge and special skills. Without the proper equipment or knowledge, EPA says, you could actually increase your radon level or create other hazards and costs.

Where to look

1. Your state radon program. EPA's state contact page lists regional and state programs. Ask for its list of licensed or certified providers.
2. NRPP or NRSB. EPA lists NRPP at (828) 348-0185 and NRSB at (914) 345-1168. NRPP says it is recognized by EPA and accredited by the ANSI National Accreditation Board, and that it requires certified people to follow the applicable ANSI/AARST standards and document their competence every two years.
3. Photo ID cards. EPA says private proficiency programs usually give members a photo ID card showing their qualifications and an expiration date. If in doubt, check with the credentialing organization.

Questions to ask each contractor (EPA)

• Will you provide references, or photos and before-and-after radon test results from past jobs? Did you call the references?
• Can you explain the work, how long it will take and how the system will work?
• Did you inspect my home's structure before giving the estimate?
• Did you review the quality of my radon test results?
• Do you charge for diagnostic tests?

What the estimate should include (EPA)

• Proof of state certification or professional proficiency credentials.
• Proof of liability insurance, being bonded and having required local licenses.
• Diagnostic testing before the system is designed and installed.
• A warning device that alerts you if the system stops working.
• Testing after installation.
• A guarantee to reduce radon to 4 pCi/L or below, and for how long.

North Carolina's radon program asks homeowners to look for proof of current mitigation certification with NRPP or NRSB, proof of insurance and licenses, and notes that changing existing electrical wiring usually requires a licensed electrician.

The contract

EPA says to get a contract before any work starts and to make sure it matches the proposal. It should include the total cost with taxes and permit fees, the deposit and payment schedule, the time needed, an agreement to get permits and follow codes, liability insurance, damage and cleanup responsibility, any guarantee to reduce radon below a negotiated level, warranty details and whether warranties transfer if you sell.

Check the work

EPA says to check that the system is labeled, the exhaust pipe vents above the roof, the fan is not in or below living space, electrical work meets code and a warning device is installed. It recommends a test within 30 days, no sooner than 24 hours after the system is running, and an independent test to avoid any conflict of interest. See how mitigation systems work.

Common questions

What are NRPP and NRSB?

They are the two national radon proficiency programs EPA currently recognizes. NRPP is the National Radon Proficiency Program and NRSB is the National Radon Safety Board. EPA says its grant-receiving states must keep a public list of radon service providers credentialed through either a state-run process, such as a state license, or one of those two programs.

Does my state license radon contractors?

EPA says many states require radon professionals to be licensed, certified or registered. Contact your state radon program, which can usually give you a list of qualified providers.

What if my state does not regulate radon work?

EPA says to ask the contractor if they hold a professional proficiency or certification credential and if they follow industry consensus standards such as ASTM E2121, the standard practice for installing radon mitigation systems in existing low-rise residential buildings.

Should the installer also test afterward?

EPA recommends an independent follow-up test, because it removes any potential conflict of interest. It says a contractor may test their own work, but you should also get an independent measurement.

Related guides

• Radon mitigation cost
• How radon mitigation systems work
• Radon in a home sale
• What does my radon test result mean?